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Accurate Reporting of Expected Delivery Date by Mothers 9 Months After Birth EDITORIAL COMMENT
Abstract
To measure agreement between gestational age based on maternal report of expected date of delivery (EDD) 9 months after birth and gestational age at birth in routine hospital data. Furthermore, to examine whether sociodemographic and perinatal factors influenced agreement and whether disagreement affected classification of infants in preterm groups.
The study used data on 8,058 singleton infants from the UK Millennium Cohort Study. Women were interviewed 9 months after birth and interviews were linked to routine hospital data. The infant's date of birth and EDD were used to calculate gestational age in completed weeks.
Agreement between maternal report and hospital data was 72% for exact number of weeks' gestation and 94% for agreement within 1 week. Disagreement was associated with the infant not being firstborn, unplanned pregnancy, late or no antenatal care, and low socioeconomic status. Maternal report of gestational age resulted in slightly more children being classified as preterm (6.4%) than gestational age based on hospital data (6.1%). Agreement was found to be poor for postterm births.
Gestational age based on retrospective maternal reporting of EDD is reliable within 1 week or when used to assign infants to broad gestational groups.
... Gestational age in weeks was ascertained from the mother's report of estimated date of delivery and actual date of birth. This information has been shown to have high agreement with linked routine hospital records, except for births post term (≥42 weeks) [15]. Completed gestational weeks were categorised as 23-32 weeks (very preterm), 32-33 weeks (moderately preterm), 34-36 weeks (late preterm), 37-38 weeks (early term), 39 weeks, 40 weeks (both defined full term) and 41 weeks (late term) ( Table 1) [16]. ...
... Of the 18,818 children recruited to the MCS, 12,990 (69%) participated in the age 11 survey (Figure 1). Children were excluded if the mother was not the main respondent at the initial survey or if gestational age was missing or implausible given the reported birthweight [15,17]. Post term births were excluded due to lower data quality [15]. ...
... Children were excluded if the mother was not the main respondent at the initial survey or if gestational age was missing or implausible given the reported birthweight [15,17]. Post term births were excluded due to lower data quality [15]. Children with missing data on SEN or confounders were also excluded. ...
Objective
To examine the association between gestational age at birth across the entire gestational age spectrum and special educational needs (SENs) in UK children at 11 years of age.
Methods
The Millennium Cohort Study is a nationally representative longitudinal sample of children born in the UK during 2000–2002. Information about the child’s birth, health and sociodemographic factors was collected when children were 9 months old. Information about presence and reasons for SEN was collected from parents at age 11. Adjusted relative risks (aRRs) were estimated using modified Poisson regression, accounting for confounders.
Results
The sample included 12 081 children with data at both time points. The overall prevalence of SEN was 11.2%, and it was inversely associated with gestational age. Among children born <32 weeks of gestation, the prevalence of SEN was 27.4%, three times higher than among those born at 40 weeks (aRR=2.89; 95% CI 2.02 to 4.13). Children born early term (37–38 weeks) were also at increased risk for SEN (aRR=1.33; 95% CI 1.11 to 1.59); this was the same when the analysis was restricted to births after labour with spontaneous onset. Birth before full term was more strongly associated with having a formal statement of SEN or SEN for multiple reasons.
Conclusion
Children born at earlier gestational ages are more likely to experience SEN, have more complex SEN and require support in multiple facets of learning. This association was observed even among children born early-term and when labour began spontaneously.
... To our knowledge, maternal recall of birth events has not been validated in a Canadian population and few studies have involved electronic health records. According to previous studies, the validity of maternal recall varies based on the type of information23456, the way questions were worded [7] , mothers' socio-economic status [1,8,9], and length of time since the event [9,10] . Other studies, specifically those examining maternal recall of infant birth weight, suggest that age, parity, time since birth and ethnicity do not affect the validity of maternal recall [1,11]. ...
... Other studies, specifically those examining maternal recall of infant birth weight, suggest that age, parity, time since birth and ethnicity do not affect the validity of maternal recall [1,11]. The majority of validation studies have focused on maternal recall of infant birth weight, gestational age and/ or mode of delivery1234568910111213141516171819. Generally, they have found that maternal recall for these variables is excellent. ...
... A US study found that 89% of 46,637 women sampled could recall their infant's birth weight within one ounce when compared to the weight recorded on the medical charts [13], while a British study found that 91% of 649 mothers were able to recall their infant's birth weight within 200g compared to medical charts [16]. Another study conducted in the UK, determined that 94.5% of 8037 women could recall their infants gestational age at birth within one week of the gestational age found in the medical charts [8]. Other studies showed that maternal recall of gestational age is less accurate than their recall of birth weight, but concluded that maternal recall of both gestational age and birth weight are valid [1,2,6,9,15,19]. ...
Maternal report of events that occur during labour and delivery are used extensively in epidemiological research; however, the validity of these data are rarely confirmed. This study aimed to validate maternal self-report of events that occurred in labour and delivery with data found in electronic health records in a Canadian setting.
Data from the All Our Babies study, a prospective community-based cohort of women's experiences during pregnancy, were linked to electronic health records to assess the validity of maternal recall at four months post-partum of events that occurred during labour and delivery. Sensitivity, specificity and kappa scores were calculated. Results were stratified by maternal age, gravidity and educational attainment.
Maternal recall at four months post-partum was excellent for infant characteristics (gender, birth weight, gestational age, multiple births) and variables related to labour and delivery (mode of delivery, epidural, labour induction) (sensitivity and specificity >85%). Women who had completed a university degree had significantly better recall of labour induction and use of an epidural.
Maternal recall of infant characteristics and events that occurred during labour and delivery is excellent at four months post-partum and is a valid source of information for research purposes.
... Those born post-term (≥ 42 weeks) were also excluded due to known poor agreement between maternal recall and hospital records for this group in the MCS. 23 In this study, children with valid information on their SCD on at least one of all five waves (i.e. age 3, 5, 7, 11 and 14 interviews) were included, resulting in 15,821 children in the analytic sample ( Figure S1). ...
... Gestational age in weeks was calculated based on the mother's report of the expected due date, which corresponded well with gestational age recorded in the linked hospital data. 23 Children were divided into four groups based on their reported-gestational age: ...
Objectives
To examine if gestational age groups predict the development of social competence difficulties (SCDs) from childhood into mid-adolescence and to assess the mediation by maternal psychological distress during infancy on these trajectories.
Design
Nationally representative population-based birth cohort (UK Millennium Cohort Study).
Participants
15 821 children born in 2000–2002.
Outcome measures
SCDs (derived from peer and prosocial subscales of Strengths and Difficulties Questionnaire) were assessed by parent report when the participants were aged 3, 5, 7, 11 and 14 years. Maternal psychological distress was self-rated using Rutter Malaise Inventory when the children were 9 months of age. Data were modelled using latent growth curve analysis.
Results
Developmental trajectories of SCDs were U-shaped in all groups. Very preterm (VP) children (<32 weeks, n=173) showed pronounced difficulties throughout, with the coefficient difference from the full term at age 14 being 0.94 (95% CI 0.23 to 1.66, equivalent to 0.32 SD of the population average SCDs). Moderate-to-late preterm children (32–36 weeks, n=1130) and early-term children (37–38 weeks, n=3232) showed greater difficulties compared with the full-term peers around age 7 years, which resolved by age 14 years (b=0.20, 95% CI –0.05 to 0.44; b=0.03, 95% CI –0.12 to 0.17, respectively). Maternal psychological distress during infancy mediated 20% of the aforementioned association at age 14 years for the VP.
Conclusion
There was a dose–response association between gestational age and the trajectories of SCDs. Monitoring and providing support on social development throughout childhood and adolescence and treating early maternal psychological distress may help children who were born earlier than ideal, particularly those born VP.
... We observed both low individual-level accuracy and high population-level bias for the preterm birth indicator generated from maternal reports of length of gestation at birth. Several studies have reported high degrees of accuracy of gestational age reports from mothers in developed countries [19,21,22,34,35]. One study conducted in the US Nurses' Health Studies population reported moderate sensitivity (68%) and high specificity (92%) using maternally reported gestational age to classify preterm birth [20]. ...
... We also observed slight improvements in maternal report accuracy associated with maternal education, consistent other studies' findings [19,22,26,27]. Finally, across all three indicators, we found that multiparous mothers had greater accuracy compared to first-time mothers, which contrasts with patterns described in prior studies [19,26,27,35]. ...
Background
Tracking progress towards global newborn health targets depends largely on maternal reported data collected through large, nationally representative surveys. We evaluated the validity, across a range of recall period lengths (1 to 24 months post-delivery), of maternal report of birthweight, birth size and length of pregnancy.
Methods
We compared maternal reports to reference standards of birthweights measured within 72 hours of delivery and gestational age generated from reported first day of the last menstrual period (LMP) prospectively collected as part of a population-based study (n = 1502). We calculated sensitivity, specificity, area the under the receiver operating curve (AUC) as a measure of individual-level accuracy, and the inflation factor (IF) to quantify population-level bias for each indicator. We assessed if length of recall period modified accuracy by stratifying measurements across time bins and using a modified Poisson regression with robust error variance to estimate the relative risk (RR) of correctly classifying newborns as low birthweight (LBW) or preterm, adjusting for child sex, place of delivery, maternal age, maternal education, parity, and ethnicity.
Results
The LBW indicator using maternally reported birthweight in grams had low individual-level accuracy (AUC = 0.69) and high population-level bias (inflation factor IF = 0.62). LBW using maternally reported birth size and the preterm birth indicator had lower individual-level accuracy (AUC = 0.58 and 0.56, respectively) and higher population-level bias (IF = 0.28 and 0.35, respectively) up to 24 months following birth. Length of recall time did not affect accuracy of LBW indicators. For the preterm birth indicator, accuracy did not change with length of recall up to 20 months after birth and improved slightly beyond 20 months.
Conclusions
The use of maternal reports may underestimate and bias indicators for LBW and preterm birth. In settings with high prevalence of LBW and preterm births, these indicators generated from maternal reports may be more vulnerable to misclassification. In populations where an important proportion of births occur at home or where weight is not routinely measured, mothers perhaps place less importance on remembering size at birth. Further work is needed to explore whether these conclusions on the validity of maternal reports hold in similar rural and low-income settings.
... Prior validation studies have shown that maternal recall of preterm or SGA birth is good (sensitivity >0.90). 16,17 Women in the current analysis were categorized into 3 exposure groups: those who ever experienced a PTB, those with a prior term SGA birth, and those with all term and AGA births. ...
Objective:
To examine whether blood pressure (BP) accelerates more rapidly during the menopause transition for women with a history of preterm or term small for gestational age (SGA) delivery compared to women with all term and appropriate for gestational age (AGA) births.
Methods:
A longitudinal analysis was conducted with 1,008 parous women who had BP data at ≥2 study visits. We used generalized linear modeling to examine BP before the final menstrual period, at the final mentrual period, and up to 10 years after the final menstrual period, according to pregnancy group. We assessed maternal changes in BP over time in relation to years near the final menstrual period using a piece-wise linear model, consistent with menopause-induced changes. Models were adjusted for socio-demographics, body mass index, smoking, physical activity, medications, parity, age at first birth, gestational diabetes, and gestational hypertension/preeclampsia.
Results:
At baseline, women were on average 46 years old, 101 (10%) reported a prior preterm birth, and 102 (10.1%) reported a term SGA birth. Compared to women with all term AGA births, women with a term SGA birth had higher BP before the final menstrual period, at the final menstrual period, and up to 10 years after the final menstrual period; women with a preterm birth had higher BP in the postmenopausal years. Annual rate of change in BP during the menopause transition did not differ between pregnancy groups.
Conclusions:
Women with a history preterm and term SGA delivery have higher BP than women with all term AGA births during the menopause transition, but rate of change in BP does not differ in these groups relative to final menstrual period.
... Parents were interviewed for the first time when the children were aged 9 months (survey 1), and again at 14 years (survey 6). Validity of parent-reported gestational age at 9 months after birth has been reported by Poulsen and colleagues [27]. Cross-sectional data at wave 6 were used for the current study, when participants were 14.2 years old (SD = 0.3). ...
This study examined whether physical activity is associated with better mental health and well-being among very preterm (≤32 weeks) and term born (≥37 weeks) adolescents alike or whether the associations are stronger in either of the groups. Physical activity was measured with accelerometry in children born very preterm and at term in two cohorts, the Basel Study of Preterm Children (BSPC; 40 adolescents born ≤32 weeks of gestation and 59 term born controls aged 12.3 years) and the Millennium Cohort Study (MCS; 45 adolescents born ≤32 weeks of gestation and 3137 term born controls aged 14.2 years on average). In both cohorts, emotional and behavioral problems were mother-reported using the Strengths and Difficulties Questionnaire. Subjective well-being was self-reported using the Kidscreen-52 Questionnaire in the BSPC and single items in the MCS. Hierarchical regressions with ‘preterm status × physical activity’-interaction effects were subjected to individual participant data (IPD) meta-analysis. IPD meta-analysis showed that higher levels of physical activity were associated with lower levels of peer problems, and higher levels of psychological well-being, better self-perception/body image, and school related well-being. Overall, the effect-sizes were small and the associations did not differ significantly between very preterm and term born adolescents. Future research may examine the mechanisms behind effects of physical activity on mental health and wellbeing in adolescence as well as which type of physical activity might be most beneficial for term and preterm born children.
... Parents were interviewed for the first time when the children were aged 9 months (survey 1), and again at 14 years (survey 6). Validity of parent-reported gestational age at 9 months after birth has been reported by Poulsen and colleagues [27]. Cross-sectional data at wave 6 were used for the current study, when participants were 14.2 years old (SD = 0.3). ...
Preprint manuscriptVery preterm birth is a risk factor for later mental health problems. This study examined whether physical activity is associated with better mental health and well-being among very preterm (≤32 weeks) and term born (≥37 weeks) adolescents alike or whether the associations are stronger in either of the groups. Physical activity was measured with accelerometry in children born very preterm and at term in two cohorts, the Basel Study of Preterm Children (BSPC; 40 adolescents born ≤ 32 weeks of gestation and 59 term born controls aged 12.3 years) and the Millennium Cohort Study (MCS; 45 adolescents born ≤ 32 weeks of gestation and 3,137 term born controls aged 14.2 years). In both cohorts, emotional and behavioural problems were mother-reported using the Strengths and Difficulties Questionnaire. Subjective well-being was self-reported using the Kidscreen-52 Questionnaire in the BSPC and single items in the MCS. Hierarchical regressions with ‘preterm status x physical activity’-interaction effects were subjected to individual participant data (IPD) meta-analysis. IPD meta-analysis showed that higher levels of physical activity were associated with lower levels of emotional symptoms and peer problems, higher levels of psychological well-being, better self-perception/body image, and school related well-being, but also higher levels of hyperactivity/inattention. Overall the effect-sizes were small and the associations did not differ significantly between very preterm and term born adolescents. Physical activity was associated with lower levels of emotional and peer problems and higher levels of subjective well-being among adolescents, irrespective of whether they were born very preterm or at term.
... Although maternal recall is often used to characterise reproductive histories, studies examining validity through agreement between maternal recall and routine hospital records have largely been confined to high-income countries. [9][10][11] Gichane et al 12 carried out the first study in Cape Town, South Africa, to assess pregnancy outcomes and maternity service use in a sample of signing Deaf women. Deaf (capitalised) refers to those permanently, sensorily disabled people with congenital or early-onset deafness and whose first language is signed, referred to in this country as South African Sign Language (SASL). ...
Introduction
There is little credible quantitative data on pregnancy histories and outcomes for disabled women in low-income and middle-income countries. The purpose of this study, based in Cape Town, South Africa, was to test the reliability and validity of maternal recall of pregnancy history and service use among a sample of Deaf women who use South African Sign Language (SASL).
Methods
We interviewed 42 signing Deaf women of childbearing age (18–49 years) in SASL using a structured questionnaire in July 2016. To assess reliability, seven participants (16% of the sample) were reinterviewed by different interviewers under the same conditions after 10–30 min. For the analysis we used (1) Cohen’s kappa, an inter-rater statistical method, and (2) overall percentage agreement. Validity was explored by comparing the participants’ pregnancy history to the Western Cape Provincial Health Data Centre (PHDC) database.
Results
The reliability results showed that out of 19 questions 14 demonstrated substantial to perfect agreement kappa scores (kappa between 0.61 and 1) and 5 had the lowest kappa agreement scores (kappa <0.61). With respect to percentage agreement, participants provided identical responses in 87% cases. Overall, women provided more reliable responses to pregnancy outcomes compared with demographic information. Validity results showed that 29 out of 35 Deaf women provided survey responses that matched or nearly matched (83% agreement) the PHDC database for birth history and delivery location.
Conclusion
This study suggests that for this sample of signing Deaf women recall of pregnancy history and service use is reliable and valid. Extending this approach to other similar populations will require further research, but it is important that methods to access hard-to-reach disabled populations are developed so that health system responsiveness to marginal populations can be based on robust evidence.
... Gestational age was calculated using the mother's recall of her gestational due date, which was previously found to have good agreement with hospital records. 16 Gestational age was categorised into very preterm (<32 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks) and full term (39-41 weeks). ...
Objective
Children born preterm have an increased risk of asthma in early childhood. We examined whether this persists at 7 and 11 years, and whether wheezing trajectories across childhood are associated with preterm birth.
Design
Data were from the UK Millennium Cohort Study, which recruited children at 9 months, with follow-up at 3, 5, 7 and 11 years.
Outcomes
Adjusted ORs (aOR) were estimated for recent wheeze and asthma medication use for children born <32, 32–33, 34–36 and 37–38 weeks’ gestation, compared with children born at full term (39–41 weeks) at 7 (n=12 198) and 11 years (n=11 690). aORs were also calculated for having ‘early-remittent’ (wheezing at ages 3 and/or 5 years but not after), ‘late’ (wheezing at ages 7 and/or 11 years but not before) or ‘persistent/relapsing’ (wheezing at ages 3 and/or 5 and 7 and/or 11 years) wheeze.
Results
Birth <32 weeks, and to a lesser extent at 32–33 weeks, were associated with an increased risk of wheeze and asthma medication use at ages 7 and 11, and all three wheezing trajectories. The aOR for ‘persistent/relapsing wheeze’ at <32 weeks was 4.30 (95% CI 2.33 to 7.91) and was 2.06 (95% CI 1.16 to 2.69) at 32–33 weeks. Birth at 34–36 weeks was not associated with asthma medication use at 7 or 11, nor late wheeze, but was associated with the other wheezing trajectories. Birth at 37–38 weeks was not associated with wheeze nor asthma medication use.
Conclusions
Birth <37 weeks is a risk factor for wheezing characterised as ‘early-remittent’ or ‘persistent/relapsing’ wheeze.
... However, key measures such as the EPDS and perceptions of their infant were reported at the same time as the survey return and recall of earlier salient events around childbirth, such as gestational age, is generally good. [28][29][30] Over 95% of women had a dating scan in early pregnancy so their reports of gestational age are likely to be reasonably accurate. A further limitation was that the items relating to antenatal and postnatal health were based on a symptom checklist rather than validated measures, however, the EPDS as a standard measure was also used in collecting data on maternal well-being. ...
Background
Approximately 15 million babies were born preterm worldwide in 2010 and in England in 2014 there were 52 249 preterm births. Preterm babies are at increased risk of poor outcomes and this can put enormous strain on the family.
Objective
This study aimed to test the hypothesis that giving birth preterm affects maternal health, mood and well-being, and alters women's feelings and perceptions about their baby.
Methods
Data collected in a population-based survey of maternity care in England in 2014 were used. Women were randomly selected and asked about their pregnancy, birth and postnatal experience when their babies were about 3 months of age. Descriptive statistics were produced, and logistic regression used to estimate ORs, adjusted for key confounders.
Main outcome measures—Women's self-reported postnatal health, Edinburgh Postnatal Depression Scale, women's perceptions of their baby.
Results
4578 women returned completed questionnaires. Of these, 42 (0.9%) had babies born before 32 weeks' gestation and 243 (5.5%) at 32–36 weeks. Comparing the three gestational age groups, no statistically significant differences in rates of depressive symptoms measured on the Edinburgh Postnatal Depression Scale were found. However, using a health problems checklist, anxiety, fatigue and flash-backs were more common in mothers of preterm babies. Overall, mothers of preterm babies had less early contact with their baby, more postnatal health problems, substantially less positive feelings towards their baby and made less use of the support options available.
Conclusions
Women with preterm births are at increased risk of ill-health and negative feelings about their baby in the early months after birth. They make less use of postnatal services and support than other women and this may be an area where the use of specialist services would be appropriate.
... Gestational age was derived from maternal report of the expected due date during the 9 month interview, which was based on the date of the last menstrual period and results of the antenatal ultrasound scan. These data have been shown to provide an accurate estimation when compared to linked hospital database records [18]. Children with valid accelerometry data were divided into four groups based on gestational age at birth: 25-32, 33-34, 35-36 and 37-43 weeks' gestation (term control). ...
Background:
Previous studies of preterm-born children (<37 weeks' gestation) have demonstrated decrements in lung function, exercise capacity, and increased respiratory symptoms compared to their term-born peers. However, it is unclear if these children have decreased levels of physical activity (PA) and increased sedentary behavior as a consequence of this increased respiratory morbidity. We therefore compared objectively measured PA in 7-year old preterm-born children with those born at term.
Methods:
Children in the Millennium Cohort Study underwent assessment of PA at 7 years of age using accelerometry. 6422/12781 (50%) provided valid accelerometry and had gestational age data. A series of general linear models adjusted for confounders investigated the association between gestational age and levels of Total PA (average accelerometer counts per minute over the period of the recording), Moderate-to-Vigorous PA (MVPA) and sedentary behavior. Mediation analysis was performed to specifically investigate whether the observed association of gestational age on PA was mediated by respiratory symptoms.
Results:
PA data were available for 79, 119, 275 and 5949 children born at 25-32, 33-34, 35-36 and 37-43 weeks' gestation respectively. Boys born at ≤32 weeks' gestation had modest but statistically significant reductions in MVPA when compared to term controls. This equated to a reduction of 9 minutes per day. No differences were found for Total PA or sedentary behavior. The association between gestational age and MVPA was not mediated by respiratory symptoms. In females, there was no association between gestational age and any measure of PA or sedentary behavior.
Conclusions:
Boys born at ≤32 weeks' gestation took part in less MVPA than their term-born peers at 7 years of age. The differences were modest, but equated to a reduction of over 1 hour per week. Since PA levels have been shown to decline during childhood and adolescence, this vulnerable group deserves further surveillance.
... Gestational age was reported by the natural mother, and has previously been validated against linked Hospital Episodes Statistics data. 39 Implausible values were excluded, by assessing reported birth weight and gestational age against standard growth percentiles (N=90 excluded). To examine whether the risk of PD increased with greater prematurity, we grouped births as very preterm (<32 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), full-term (39-41 weeks) and post-term (≥42 weeks). ...
Objective
To assess whether the parents of babies born preterm (PT; <37 weeks completed gestation) are at excess risk of psychological distress (PD) at 9 months postpartum, and to explore the influence of the degree of prematurity.
Design and participants
Data were drawn from the UK Millennium Cohort Study, a nationally representative prospective cohort of babies born in 2000–2002. 12 100 families with complete data available for both parents at recruitment (9 months postpartum) are included.
Exposure and outcome
Mothers report of gestational age at birth (in weeks) was grouped into: very PT (<32 weeks), moderately PT (32–33 weeks), late PT (34–36 weeks), early term (37–38 weeks), full-term (39–41 weeks), post-term (42 weeks). PD was assessed using a modified Rutter Malaise Inventory, a validated instrument that has been used in both men and women to assess levels of anxiety and distress.
Results
Overall, 7% of families reported a PT birth; 12.1% of mothers and 8.9% of fathers showed signs of PD at 9 months postpartum. The mothers of very PT infants had an increased risk of PD, compared with the mothers of full-term babies (unadjusted OR 2.10 (1.30 to 3.39; adjusted OR 1.66 (1.02 to 2.69)). Mothers of moderate or late PT babies had no apparent increased risk of PD. However, mothers of early term babies also showed a small excess risk of PD (adjusted OR 1.16 (0.99 to 1.36)). Unadjusted analysis suggested a doubling in the risk of PD in fathers of very and moderately PT babies, compared with fathers of full-term babies, which remains statistically significant after adjustment in the moderately PT group (adjusted OR1.98 (1.20 to 3.29)).
Conclusions
The parents of very PT children are at an increased risk of PD at 9 months postpartum, and mothers of children born at early term also see an elevated risk compared with mothers of full-term babies.
... Cross-sectional designs meant that outcome data were generally complete, and the two longitudinal studies identified had high retention rates. 3 9 20 Given the salience of stillbirth and surrounding events to women and partners, and evidence of the reliability of women's self-report regarding events around birth, [67][68][69] information collected from women probably represents the most effective and accurate estimate of whether or not women held their stillborn baby. As noted in the results, no studies clearly defined and assessed the way the infant was held (eg, skin-to-skin, timing or duration). ...
Objective
To collate and critically appraise extant evidence for the impact of contact with the stillborn infant on parental mental health, well-being and satisfaction.
Design
Systematic review.
Data sources
A structured systematic search was conducted in 13 databases, complemented by hand-searching.
Study eligibility criteria
English language studies providing quantitative comparison of outcomes for parents who held their baby or engaged in other memory-making activities, such as having photos and handprints, compared to those who did not, were eligible for inclusion.
Outcome measures
Primary outcomes included clinically diagnosed mental health issues, standardised assessment of mental health issues or self-reported psychological distress. Secondary outcomes included poor health, relationship difficulties and satisfaction with the decision to have contact with the baby.
Results
Two authors independently screened abstracts, selected potentially eligible studies, extracted data and evaluated the quality of included papers. 11 eligible studies, reported in 18 papers, were included. Studies were heterogeneous, precluding quantitative synthesis, thus a narrative synthesis is presented. Studies presented high risks of bias, particularly in regard to sample representativeness, and confounder identification and adjustment. Results were mixed concerning the impact of holding the stillborn baby on mental health and well-being. One study found no significant effects, and two studies reported no impact on depression. Conflicting effects were found for anxiety and post-traumatic stress. Other memory-making activities were not found to have a significant association with mental health or well-being outcomes. Across studies, mothers were satisfied with their decision to hold their baby or engage in other memory making.
Conclusions
Evidence for the impact of holding the stillborn baby on mental health and well-being is sparse, and of poor quality. High-quality research guided by a priori hypotheses, with attention to potential confounders and moderating effects, is needed to provide more rigorous evidence to guide practitioners’ and parents’ decision-making for care following stillbirth.
Review protocol number
PROSPERO CRD42014013890.
... Cross-sectional designs meant that outcome data were generally complete, and the two longitudinal studies identified had high retention rates. 3 9 20 Given the salience of stillbirth and surrounding events to women and partners, and evidence of the reliability of women's self-report regarding events around birth, [67][68][69] information collected from women probably represents the most effective and accurate estimate of whether or not women held their stillborn baby. As noted in the results, no studies clearly defined and assessed the way the infant was held (eg, skin-to-skin, timing or duration). ...
Background Stillbirth is a devastating event for women and their partners. Actions surrounding the stillbirth, have been identified as critical events with short and long term implications. Standard care for parents has changed over time and it is essential that present guidelines for care reflect best available evidence. This systematic review aimed to collate and critically appraise evidence for the impact of contact with the stillborn infant on parental mental health, wellbeing and satisfaction.
Methods Studies providing quantitative comparison of outcomes for parents who held their baby or engaged in other memory-making activities, such as having photos and handprints, compared to those who did not were eligible for inclusion. Primary outcomes included clinically diagnosed mental health issues, standardised assessment of mental health issues or self-reported psychological distress. Secondary outcomes included poor health, relationship difficulties, and satisfaction with the decision to have contact with the baby. Structured systematic searching was conducted in thirteen databases, complemented by hand-searching. Titles and abstracts were screened for eligibility by two reviewers. Study quality was appraised by two reviewers using a framework based on a recent assessment of quality appraisal tools for observational studies. Narrative synthesis was undertaken and standardised measures of effects calculated for each study to aid comparison. Methodological heterogeneity precluded meta-analysis.
Results Searches returned 1,294 unique titles. Two authors independently screened titles and abstracts, and assessed 29 full-text articles were assessed. Eleven studies reported in eighteen papers met criteria. Studies were heterogeneous in approach and presented high risks of bias, particularly in regards to sample representativeness, and confounder adjustment. Results were mixed concerning the impact of holding the stillborn on mental health and wellbeing. One study found no significant effects on any outcomes, and two studies reported no impact on depression. Conflicting effects were found for anxiety and posttraumatic stress. Other memory-making activities were not found to have a significant association with mental health or wellbeing outcomes. Across studies, mothers were satisfied with their decision to hold their baby or engage in other memory-making activities.
Conclusion Evidence for the impact of holding the stillborn baby on mental health and wellbeing is sparse and of poor quality. High quality research guided by a-priori hypotheses, with attention to potential confounders and moderating effects, is needed to provide more rigorous evidence to guide practitioners and parents’ decision-making for care following stillbirth.
... Previous studies have shown that there is good agreement between mothers' self-report of baby's birth weight, gestation and mode of delivery compared to hospital records. [31][32][33] Birth weight was classified as ≥2.5 kg ('normal') or <2.5 kg ('low'). Gestation was recorded in weeks and classified as <28, 28-32, 33-36 or ≥37 weeks. ...
Objectives There has been very little description of the health and social outcomes at pregnancy and early motherhood of girls who were previously looked after by local authorities. The objectives of this study were to compare the sociodemographic and health profiles of mothers who had spent time in a children's home or with foster parents as a child to mothers who had not. In particular, to examine associations between being looked after and the likelihood of smoking during pregnancy, birth weight, the presence of symptoms of maternal depression and the initiation of breastfeeding.
Design A retrospective cross-sectional study using the baseline questionnaire of the Millennium Cohort Study.
Setting The UK.
Participants A nationally representative study of 18 492 mothers of babies born in the UK during 2000–2002.
Exposure A history of spending time in a children's home or with foster parents.
Outcome measures (1) Smoking during pregnancy; (2) low birth weight; (3) symptoms of maternal depression and (4) initiation of breastfeeding.
Results In univariable analyses, women who had been looked after by local authorities were significantly less likely to be of a higher social class, live in a high-income household or have achieved a high level of education. They were more likely to have a low-birthweight baby and be a single parent. In multivariable analyses, women who had been looked after by local authorities were more likely to smoke during pregnancy (adjusted OR 3.0 95% CI 2.14 to 4.3) and were more likely to have symptoms of depression (adjusted OR 1.98 95% CI 1.4 to 2.7) compared with women who had not been looked after.
Conclusions Our results suggest that these women carry social disadvantage into motherhood, with the potential of continuing the cycle of deprivation. There is a case for increasing our attention on this group, which can be readily accessed by maternity and early years’ services.
Background
Preterm birth (PTB) and small-for-gestational-age (SGA) disproportionately affect women who are Black or Asian. Structural racism produces health inequalities. Identifying latent socioeconomic classes may help to understand the role socioeconomic position (SEP) plays in this inequality.
Methods
We included women from the baseline survey of the UK-based Millennium Cohort Study who had a live singleton pregnancy and gave birth from 1 September 2000 to 11 January 2002. Relative risks (RR) with 95% confidence intervals (CI) for PTB and SGA were estimated for ethnic groups compared with women who were white, with adjustment for SEP. Latent SEP classes were then identified using diverse prospective socioeconomic data. Mediation of health inequality via SEP and latent SEP class was tested.
Results
Among 17 701 included women, 6.7% (95% CI 6.2%, 7.1%) experienced PTB and 7.0% (6.5%, 7.5%) SGA. We found evidence that the association between ethnic groups and PTB was mediated by latent SEP class for women who were Bangladeshi, Black African, Black Caribbean and Pakistani, with indirect ‘effects’ of RR 1.08 (1.01, 1.16), 1.07 (1.01, 1.14), 1.06 (1.00, 1.12) and 1.06 (1.00, 1.13), respectively, relative to White. When using the simple measures of maternal education, household income and marital status, we found no evidence of mediation except for a potential protective effect among Indian women, relative to White. We found similar evidence for SGA, with indirect effects through latent SEP class of RR 1.35 (1.19, 1.52), 1.32 (1.17, 1.48), 1.26 (1.12, 1.41), 1.27 (1.13, 1.42), respectively. When using the simple measures, we found evidence of mediation only among Black African and Black Caribbean women, with RR 1.16 (1.04, 1.30) and 1.12 (1.00, 1.26), respectively, relative to White.
Conclusion
The determinants of inequality appeared to differ by ethnicity. We demonstrated the mediating role of individual-level SEP and a role for latent class analysis to interpret complex combinations of socioeconomic data.
Preterm born individuals have an increased risk for mental health problems. Participation in club sport is associated with better mental health but the causal direction is unclear. It is not known whether this association could also be found in preterm children. Data from term born (N = 10,368), late preterm (N = 630), and very to moderately preterm born (N = 243) children from the Millennium Cohort Study at the ages of 3, 5, 7, 11, and 14 years were used. Longitudinal associations between the parent-reported Strengths and Difficulties questionnaire (SDQ) and club sport participation (days per week) were analysed using multigroup structural equation modelling, adjusting for gender, maternal depression, parental education; motor problems and attrition were controlled for. Multi-group structural equation modelling showed that children with more peer relationship problems, emotional symptoms, conduct problems or hyperactivity-inattention were less likely to participate in club sport at subsequent assessment time points. More days with club sport participation was associated with lower levels of emotional symptoms and peer relationship problems but not conduct problems or hyperactivity-inattention at subsequent ages. Results were similar in all gestational age groups. Club sport participation predicts lower levels of peer relationship and emotional problems in subsequent waves while it is also predicted by lower levels of emotional problems, peer relationship problems, conduct problems and hyperactivity-inattention in preceding waves. Since no differences in the relationship between SDQ subscales and club sport participation were seen with regard to gestational age groups, club sport should be encouraged in all children.
The current study tested whether the reported lower wellbeing of parents after preterm birth, relative to term birth, is a continuation of a pre-existing difference before pregnancy. Parents from Germany (the German Socio-Economic Panel Study, N = 10,649) and the United Kingdom (British Household Panel Study and Understanding Society, N = 11,012) reported their new-born’s birthweight and gestational age, subsequently categorised as very preterm or very low birthweight (VP/VLBW, < 32 weeks or < 1500 g), moderately/late preterm or low birthweight (MLP/LBW, ≥ 32 weeks and < 37 weeks/≥ 1500 g and < 2500 g), or term-born (≥ 37 weeks and ≥ 2500 g). Mixed models were used to analyse life satisfaction, an aspect of wellbeing, at four assessments-two years and six months before birth and six months and two years afterwards. Two years before birth, satisfaction of prospective term-born, MLP/LBW, or VP/VLBW mothers did not significantly differ. However, mothers of VP/VLBWs had lower satisfaction relative to mothers of term-borns at both assessments post-birth. Among fathers, satisfaction levels were similarly equivalent two years before birth. Subsequently, fathers of VP/VLBWs temporarily differed in satisfaction six months post-birth relative to fathers of term-borns. Results indicate that parents’ lower life satisfaction after VP/VLBW birth is not a continuation of pre-existing life satisfaction differences.
Importance:
Birth weight percentiles (BWPs) are often dichotomized at the 10th percentile and show statistically significant association with later cognitive performance, for both preterm and term-born children. However, research testing nonlinear associations between BWPs and cognitive performance is scarce.
Objective:
To investigate culturally invariant, nonlinear associations of BWPs and gestational age with later cognitive performance.
Design, setting, and participants:
In this cohort study, participants with valid neonatal and cognitive data were combined from 4 observational cohorts, including the Millennium Cohort Study, the National Longitudinal Survey of Youth 1979 Child and Young Adult cohort, Growing Up in Ireland, and the Longitudinal Study of Australian Children, with children born between 2000 and 2002, 1980 and 2010, 2007 and 2008, and 2003 and 2004, respectively. Neonatal data were parent reported before age 1 year. At approximately 5 years of age, multiple cognitive tests were performed. Follow-up at 5 years of age was the predominant focus. Data were analyzed July 17, 2023.
Exposure:
The parent-reported neonatal data were used to calculate BWPs according to the Fenton growth chart.
Main outcome and measure:
Scores for IQ were created from multiple measures of cognition, which were z standardized separately within each cohort.
Results:
Of 30 643 participants (50.8% male), 7.5% were born preterm (before 37 weeks gestation) and 92.5% were term born (between 37 and 42 weeks gestation). In the pooled data using multivariate adaptive regression splines, IQ linearly increased by 4.2 points as BWPs increased from the first to the 69th percentile before completely plateauing. For gestational age, IQ linearly increased by 1.3 points per week up until 32 weeks, with the association reducing to 0.3 points per week after 32 weeks. The association of BWP with IQ was not moderated by gestational age. For term-born infants, the estimated IQ score was only clinically meaningfully lower than average when birth weight was below the third percentile. Consistent results were found when instead using multivariable regression where gestational age and BWPs were categorized into groups.
Conclusions and relevance:
In this cohort study, lower BWPs and gestational age were independently associated with lower IQ. For term-born infants, a cutoff of the third percentile would be more appropriate than the traditionally used 10th percentile when the aim is estimating meaningful cognitive differences.
Preterm birth (<37 weeks’ gestation) is a risk factor for poor educational outcomes. A dose-response effect of earlier gestational age at birth on poor primary school attainment has been observed, but evidence for secondary school attainment is limited and focused predominantly on the very preterm (<32 weeks) population. We examined the association between gestational age at birth and academic attainment at the end of primary and secondary schooling in England. Data for children born in England from 2000–2001 were drawn from the population-based UK Millennium Cohort Study. Information about the child’s birth, sociodemographic factors and health was collected from parents. Attainment on national tests at the end of primary (age 11) and secondary school (age 16) was derived from linked education records. Data on attainment in primary school was available for 6,950 pupils and that of secondary school was available for 7,131 pupils. Adjusted relative risks (aRRs) for these outcomes were estimated at each stage separately using modified Poisson regression. At the end of primary school, 17.7% of children had not achieved the expected level in both English and Mathematics and this proportion increased with increasing prematurity. Compared to full term (39–41 weeks) children, the strongest associations were among children born moderately (32–33 weeks; aRR = 2.13 (95% CI 1.44–3.13)) and very preterm (aRR = 2.06 (95% CI 1.46–2.92)). Children born late preterm (34–36 weeks) and early term (37–38 weeks) were also at higher risk with aRR = 1.18 (95% CI 0.94–1.49) and aRR = 1.21 (95% CI 1.05–1.38), respectively. At the end of secondary school, 45.2% had not passed at least five General Certificate of Secondary Education examinations including English and Mathematics. Following adjustment, only children born very preterm were at significantly higher risk (aRR = 1.26 (95% CI 1.03–1.54)). All children born before full term are at risk of poorer attainment during primary school compared with term-born children, but only children born very preterm remain at risk at the end of secondary schooling. Children born very preterm may require additional educational support throughout compulsory schooling.
Background
Several studies have reported that birth by caesarean section is associated with increased risk of lower respiratory tract infections in the child, but it is unclear whether this applies to any caesarean section or specifically to planned caesareans. Furthermore, although infections of the upper respiratory tract are very common during childhood, there is a scarcity of studies examining whether caesarean is also a risk factor for this site of infection.
Methods
We obtained data from two UK cohorts: the Millennium Cohort Study (MCS) and linked administrative datasets of the population of Wales through the Secure Anonymised Information Linkage (SAIL) databank. The study focused on term-born singleton infants and included 15,580 infants born 2000–2002 (MCS) and 392,145 infants born 2002–2016 (SAIL). We used information about mode of birth (vaginal delivery, assisted vaginal delivery, planned caesarean and emergency caesarean) from maternal report in the MCS and from hospital birth records in SAIL. Unplanned hospital admission for lower respiratory tract infection (LRTI) was ascertained from maternal report in the MCS and from hospital record ICD codes in SAIL. Information about admissions for upper respiratory tract infection (URTI) was available from SAIL only. Cox regression was used to estimate hazard ratios for each outcome and cohort separately while accounting for a wide range of confounders. Gestational age at birth was further examined as a potential added, indirect risk of planned caesarean birth due to the early delivery.
Findings
The rate of hospital admission for LRTI was 4.6 per 100 child years in the MCS and 5.9 per 100 child years in SAIL. Emergency caesarean was not associated with LRTI admission during infancy in either cohort. In the MCS, planned caesarean was associated with a hazard ratio of 1.39 (95% CI 1.03, 1.87) which further increased to 1.65 (95% CI 1.24, 2.19) when gestational age was not adjusted for. In SAIL, the adjusted hazard ratio was 1.10 (95% CI 1.05, 1.15), which increased to 1.17 (95% CI 1.12, 1.22) when gestational age was not adjusted for. The rate of hospital admission for URTI was 5.9 per 100 child years in SAIL. Following adjustments, emergency caesarean was found to have a hazard ratio of 1.09 (95% CI 1.05, 1.14) for hospital admission for URTI. Planned caesarean was associated with a hazard ratio of 1.11 (95% CI 1.06, 1.16) which increased to 1.17 (95% CI 1.12, 1.22) when gestational age was not adjusted for.
Conclusions
The risk of severe LRTIs during infancy is moderately elevated in infants born by planned caesarean compared to those born vaginally. Infants born by any type of caesarean may also be at a small increased risk of severe URTIs. The estimated effect sizes are stronger if including the indirect effect arising from planning the caesarean birth for an earlier gestation than would have occurred spontaneously. Further studies are needed to confirm these results.
Objective
To examine the association between gestational age at birth and hospital admissions to age 10 years and how admission rates change throughout childhood.
Design
Population based, record linkage, cohort study in England.
Setting
NHS hospitals in England, United Kingdom.
Participants
1 018 136 live, singleton births in NHS hospitals in England between January 2005 and December 2006.
Main outcome measures
Primary outcome was all inpatient hospital admissions from birth to age 10, death, or study end (March 2015); secondary outcome was the main cause of admission, which was defined as the World Health Organization’s first international classification of diseases, version 10 (ICD-10) code within each hospital admission record.
Results
1 315 338 admissions occurred between 1 January 2005 and 31 March 2015, and 831 729 (63%) were emergency admissions. 525 039 (52%) of 1 018 136 children were admitted to hospital at least once during the study period. Hospital admissions during childhood were strongly associated with gestational age at birth (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, and 42 weeks). In comparison with children born at full term (40 weeks’ gestation), those born extremely preterm (<28 weeks) had the highest rate of hospital admission throughout childhood (adjusted rate ratio 4.92, 95% confidence interval 4.58 to 5.30). Even children born at 38 weeks had a higher rate of hospital admission throughout childhood (1.19, 1.16 to 1.22). The association between gestational age and hospital admission decreased with increasing age (interaction P<0.001). Children born earlier than 28 weeks had an adjusted rate ratio of 6.34 (95% confidence interval 5.80 to 6.85) at age less than 1 year, declining to 3.28 (2.82 to 3.82) at ages 7-10, in comparison with those born full term; whereas in children born at 38 weeks, the adjusted rate ratios were 1.29 (1.27 to 1.31) and 1.16 (1.13 to 1.19), during infancy and ages 7-10, respectively. Infection was the main cause of excess hospital admissions at all ages, but particularly during infancy. Respiratory and gastrointestinal conditions also accounted for a large proportion of admissions during the first two years of life.
Conclusions
The association between gestational age and hospital admission rates decreased with age, but an excess risk remained throughout childhood, even among children born at 38 and 39 weeks of gestation. Strategies aimed at the prevention and management of childhood infections should target children born preterm and those born a few weeks early.
Rapid infant weight gain is a key risk factor for paediatric obesity, yet there is very little evidence on how healthy behaviours in childhood might modify this association. We aimed to examine how the association of infant weight gain with adolescent adiposity might be attenuated by moderate-to-vigorous physical activity (MVPA) in childhood.
The sample comprised 4666 children in the UK Millennium Cohort Study. The two outcomes were BMI Z-score and % fat at 14 years. Sex-stratified regression models were developed testing for interactions between infant weight Z-score gain between 0 and 3 years (continuous or categorical) and MVPA at 7 years (continuous or binary). Models were sequentially adjusted for basic covariates, socioeconomic variables, and parental BMI levels.
Effect modification was observed in boys but not girls and, among boys, was stronger for % fat than BMI. In a fully adjusted model for boys, the association between infant weight Z-score gain and adolescent % fat was 1.883 (1.444, 2.322) if MVPA < 60 min/day and 1.305 (0.920, 1.689) if MVPA ≥ 60 min/day; the difference between these two estimates being −0.578 (−1.070, −0.087). Similarly, % fat was 2.981 (1.596, 4.367) units higher among boys who demonstrated rapid infant weight gain (+0.67 to +1.34 Z-score) compared to normal weight gain (−0.67 to +0.67 Z-scores), but having MVPA ≥ 60 min/day reduced this effect size by −2.259 (−3.989, −0.535) units.
In boys, ~75% of the excess % fat at 14 years associated with rapid infant weight gain was attenuated by meeting the MVPA guideline. In boys known to have demonstrated rapid infant weight gain, increasing childhood MVPA levels, with the target of ≥60 min/day, might therefore go a long way to towards offsetting their increased risk for adolescent obesity. The lack of effect modification in girls is likely due to lower MVPA levels.
Purpose
Evaluate the association between psychotropic medication use during pregnancy and gestational age at delivery, after adjusting for depressive symptom and perceived stress severity.
Methods
We analyzed data on singleton live births from 2,914 female PRESTO participants, aged 21-45, with a reported conception from 6/2013-6/2018. Women reported psychotropic medication use at 8-12 weeks and ∼32 weeks’ gestation. We measured depressive symptoms using the Major Depressive Inventory (MDI) and perceived stress using the 10-item Perceived Stress Scale (PSS). Data on gestational age at delivery were based on self-report and/or birth certificates. We used restricted mean survival time models, stratifying by severity of depressive symptoms (MDI <25 vs. ≥25) and perceived stress (PSS <20 vs. ≥20).
Results
Two hundred and ten (7.2%) participants reported using psychotropic medications during pregnancy. Mean gestational age at delivery among women who never used psychotropic medications was 38.2 weeks (95% CI: 37.7, 38.7), while it was 37.3 weeks (95% CI: 36.7, 37.9) among women who used psychotropic medications during pregnancy. Results were similar across strata of depressive symptoms and perceived stress.
Conclusion
Our data indicate that the association between psychotropic medication use and gestational age at delivery is not confounded by indication.
Background:
Most maternal health programs in low- and middle- income countries estimate gestational age to provide appropriate antenatal care at the correct times throughout the pregnancy. Although various gestational dating methods have been validated in research studies, the performance of these methods has not been evaluated on a larger scale, such as within health systems. The objective of this research was to investigate the magnitude and impact of errors in estimated delivery dates on health facility delivery among women enrolled in a maternal health program in Zanzibar.
Methods:
This study included 4225 women who were enrolled in the Safer Deliveries program and delivered before May 31, 2017. The exposure of interest was error in estimated delivery date categorized as: severe overestimate, when estimated delivery date (EDD) was 36 days or more after the actual delivery date (ADD); moderate overestimate, when EDD was 15 to 35 days after ADD; accurate, when EDD was 6 days before to 14 days after ADD; and underestimate, when EDD was 7 days or more before ADD. We used Chi-squared tests to identify factors associated with errors in estimated delivery dates. We performed logistic regression to assess the impact of errors in estimated delivery dates on health facility delivery adjusting for age, district of residence, HIV status, and occurrence of past home delivery.
Results:
In our data, 28% of the estimated delivery dates were a severe overestimate, 23% moderate overestimate, 41% accurate, and 8% underestimate. Compared to women with an accurate delivery date, women with a moderate or severe overestimate were significantly less likely to deliver in a health facility (OR = 0.71, 95% CI: [0.59, 0.86]; OR = 0.74, 95% CI: [0.61, 0.91]). When adjusting for multiple confounders, women with moderate overestimates were significantly less likely to deliver in a health facility (AOR = 0.76, 95% CI: [0.61, 0.93]); the result moved slightly towards null for women with severe overestimates (AOR = 0.84, 95% CI: [0.69, 1.03]).
Conclusions:
The overestimation of women's EDDs reduces the likelihood of health facility delivery. To address this, maternal health programs should improve estimation of EDD or attempt to curb the effect of these errors within their programs.
Background
Oral and written language in late adolescence are influenced by many pre‐ and postnatal factors, including cognitive performance at earlier ages. We investigated whether the association between birth weight and lexical knowledge and reading comprehension in late adolescence (14–16 years) is mediated by verbal cognition during early adolescence (10–11 years).
Methods
We conducted a mediation analysis via a potential outcomes approach to data from three United Kingdom (UK) prospective birth cohorts – The National Child Development Study (NCDS; year of birth (Y.B.) = 1,958; analytic sample size (A.N.) = 9,399; original sample size (O.N.) = 18,558), British Cohort Study (BCS70; Y.B. = 1,970; A.N. = 6,591; O.N. = 17,196), and Millennium Cohort Study (MCS; Y.B. = 2,000–2,001; A.N. = 3,950; O.N. = 18,552) – to evaluate the indirect effects of birth weight on lexical knowledge (BCS and MCS) and reading comprehension measures (NCDS) in adolescence.
Results
We found an indirect effect but no statistically significant direct effects for the BCS and MCS cohorts. The proportion of the effect of birth weight on oral and written language in late adolescence mediated by early adolescence verbal cognition was 59.19% (BCS) and 8.41% (MCS) for lexical knowledge and 61.00% when the outcome was reading comprehension (NCDS). Sensitivity analyses, used to assess whether unmeasured variables could have affected our mediation estimates, showed that for reading comprehension, in NCDS, the indirect effect is robust; only unmeasured confounders highly correlated with the mediator and outcome (ρ = .68) would explain away the indirect effect. For lexical knowledge, smaller correlations with hypothetical confounders (ρ = .33 for BCS) would suffice to render the indirect effect non‐significant; the indirect effect for MCS non statistical significant.
Conclusions
Birth weight affects oral and written language skills (lexical knowledge and reading comprehension) in late adolescence via verbal cognition in early adolescence in two cohorts born in 1958 and 1970, but not in a cohort born at the turn of the millennium. These indirect effects were stronger than the direct effects and are unlikely to be explained by unmeasured confounders when the outcome involves complex skills such as reading comprehension.
Background:
Adverse pregnancy outcomes, such as preterm birth (PTB), have been associated with elevated risk of maternal cardiovascular disease, but their effect on late midlife blood pressure (BP) and subclinical vascular measures remains understudied.
Methods and results:
We conducted a cross-sectional analysis with 1220 multiethnic parous women enrolled in SWAN (Study of Women's Health Across the Nation) to evaluate the impact of self-reported history of adverse pregnancy outcomes (PTB, small-for-gestational-age, stillbirth), on maternal BP, mean arterial pressure, and subclinical vascular measures (carotid intima-media thickness, plaque, and pulse wave velocity) in late midlife. We also examined whether these associations were modified by race/ethnicity. Associations were tested in linear and logistic regression models adjusting for sociodemographics, reproductive factors, cardiovascular risk factors, and medications. Women were on average aged 60 years and 255 women reported a history of an adverse pregnancy outcome. In fully adjusted models, history of PTB was associated with higher BP (systolic: β=6.40; SE, 1.62 [P<0.0001] and diastolic: β=3.18; SE, 0.98 [P=0.001]) and mean arterial pressure (β=4.55; SE 1.13 [P<0.0001]). PTB was associated with lower intima-media thickness, but not after excluding women with prevalent hypertension. There were no significant associations with other subclinical vascular measures.
Conclusions:
Findings suggest that history of PTB is associated with higher BP and mean arterial pressure in late midlife. Adverse pregnancy outcomes were not significantly related to subclinical cardiovascular disease when excluding women with prevalent hypertension. Future studies across the menopause transition may be important to assess the impact of adverse pregnancy outcomes on midlife progression of BP.
Background:
Preterm birth and childhood poverty each adversely impact children's cognitive development and academic outcomes. In this study, we investigated whether the relationships between preterm and early term birth and children's cognitive scores at 3, 5, and 7 years old were modified by childhood poverty.
Methods:
This study was conducted by using data on singletons born at 24 to 40 weeks' gestation enrolled in the Millennium Cohort Study in the United Kingdom. Linear regression models were used to test independent and joint associations of gestational age (early or moderate preterm, late preterm, or early term compared with term) and childhood poverty (<60% of median UK income) with children's cognitive scores. Presence of additive interaction between gestational age and poverty was tested by using interaction terms.
Results:
Children born preterm (<37 weeks) or early term (37-38 weeks) tended to score more poorly on cognitive assessments than children born at term (39-40 weeks). The estimated deficits were ∼0.2 to 0.3 SD for early or moderate preterm, 0.1 SD for late preterm, and 0.05 SD for early term compared with term. Children living in poverty scored 0.3 to 0.4 SD worse than children not living in poverty on all assessments. For most assessments, the estimated effects of the 2 factors were approximately additive, with little or no evidence of interaction between gestational age and poverty.
Conclusions:
Although children born preterm who lived in poverty had the poorest cognitive outcomes, living in poverty did not magnify the adverse effect of being preterm on cognitive development.
Background:
Early-life factors can be associated with future health outcomes and are often measured by maternal recall.
Methods:
We used data from the North Carolina Early Pregnancy Study and Follow-up to characterize long-term maternal recall. We used data from the Early Pregnancy Study as the gold standard to evaluate the accuracy of pre-pregnancy weight, early pregnancy behaviors, symptoms and duration of pregnancy, and child's birthweight reported at follow-up, for 109 women whose study pregnancies had resulted in a live birth.
Results:
Most (81%) participants reported a pre-pregnancy weight at follow-up that correctly classified them by BMI category. Women reported experiencing pregnancy symptoms later at follow-up than what they reported in the Early Pregnancy Study. Accuracy of reporting of early pregnancy behaviors varied based on exposure. Overall, women who had abstained from a behavior were more likely to be classified correctly. Sensitivity of reporting was 0.14 for antibiotics, 0.30 for wine, 0.71 for brewed coffee, and 0.82 for vitamins. Most misclassification at follow-up was due to false-negative reporting. Among women who gave birth to singletons 94% could report their child's correct birthweight within ? pound and 86% could report duration of pregnancy within 7 days at follow-up.
Conclusions:
Self-report of pre-pregnancy weight, duration of pregnancy, and child's birthweight after almost 30 years was good whereas self-reported pregnancy-related exposures resulted in higher levels of reporting error. Social desirability appeared to influence women's report of their behaviors at follow-up. Self-reported assessment of confidence in the recalled information was unrelated to accuracy.
Access to reliable birth data (birthweight (BW) and gestational age (GA)) is essential for the identification of individuals who are at subsequent health risk.
This study aimed to explore the feasibility of retrospectively collecting birth data for schoolchildren from parental questionnaires (PQ) and general practitioners (GPs) in primary care clinics, in inner city neighbourhoods with high density of ethnic minority and disadvantaged populations.
Attempts were made to obtain birth data from parents and GPs for 2,171 London primary schoolchildren (34% White, 29% Black African origin, 25% South Asians, 12% Other) as part of a larger study of respiratory health.
Information on BW and/or GA were obtained from parents for 2,052 (95%) children. Almost all parents (2,045) gave consent to access their children's health records held by GPs. On the basis of parental information, GPs of 1,785 children were successfully contacted, and GPs of 1,202 children responded. Birth data were retrieved for only 482 children (22% of 2,052). Missing birth data from GPs were associated with non-white ethnicity, non-UK born, English not the dominant language at home or socioeconomic disadvantage. Paired data were available in 376 children for BW and in 407 children for GA. No significant difference in BW or GA was observed between PQ and GP data, with <5% difference between sources regardless of normal or low birth weight, or term or preterm status.
Parental recall of birth data for primary schoolchildren yields high quality and rapid return of data, and it should be considered as a viable alternative in which there is limited access to birth records. It provides the potential to include children with an increased risk of health problems within epidemiological studies.
Objectives:
We developed a new research approach, called cross-linked survey analysis, to explore how an acute exposure might lead to changes in survey responses. The goal was to identify associations between exposures and outcomes while reducing some ambiguities related to interpreting cause and effect in survey responses from a population-based community questionnaire.
Study design and setting:
Cross-linked survey analysis differs from a cross-sectional, longitudinal, and panel survey analysis by individualizing the timeline to the unique history of each respondent. Cross-linked survey analysis, unlike a repeated-measures self-matching design, does not track changes in a repeated survey question given to the same respondent at multiple time points.
Results:
Pilot data from three analyses (n = 1,177 respondents) illustrate how a cross-linked survey analysis can control for population shifts, temporal trends, and reverse causality. Accompanying graphs provide an intuitive display to readers, summarize results, and show differences in response distributions. Population-based individual-level linkages also reduce selection bias and increase statistical power compared with a single-center cross-sectional survey. Cross-linked survey analysis has limitations related to unmeasured confounding, pragmatics, survivor bias, statistical models, and the underlying artifacts in survey responses.
Conclusion:
We suggest that a cross-linked survey analysis may help in epidemiology science using survey data.
Objective To investigate the effect of gestational age, particularly late preterm birth (34–36 weeks gestation) and early term birth (37–38 weeks gestation) on school performance at age 7 years.
Design Population-based prospective UK Millennium Cohort Study, consisting of linked educational data on 6031 children.
Methods School performance was investigated using the statutory Key Stage 1 (KS1) teacher assessments performed in the third school year in England. The primary outcome was not achieving the expected level (≥level 2) of general performance in all three key subjects (reading, writing and mathematics). Other outcomes investigated subject-specific performance and high academic performance (level 3).
Results 18% of full-term children performed below the expected KS1 general level, and risk of poor performance increased with prematurity: compared to children born at full-term, there was a statistically significant increased risk of poor performance in those born very preterm (<32 weeks gestation, adjusted RR 1.78, 95% CI 1.24 to 2.54), moderately preterm (32–33 weeks gestation, adjusted RR 1.71, 95% CI 1.15 to 2.54) and late preterm (34–36 weeks gestation, adjusted RR 1.36, 95% CI 1.09 to 1.68). Early term children performed statistically significantly worse in 4 out of 5 individual subject domains than full-term children, but not in the primary outcome (adjusted RR 1.07, 95% CI 0.94 to 1.23).
Conclusions Late preterm, and to a lesser extent, early term birth negatively impact on academic outcomes at 7 years as measured by KS1 assessments.
Objective
To examine how cognitive ability is related to gestational age and the extent to which observed differences could be explained by socio-economic confounding.Methods
The Millennium Cohort Study collected data on 18 818 children at 9 months and 3, 5 and 7 years. Cognitive development was assessed using Bracken School Readiness Assessment at age 3, British Ability Scales II at ages 3, 5 and 7 and progress in mathematics at 7 years. Z-scores were analysed by linear regression with adjustment for confounders.ResultsChildren born at
Recent studies suggest that children born at late preterm (34-36 weeks gestation) and early term (37-38 weeks) may have poorer developmental outcomes than children born at full term (39-41 weeks). We examined how gestational age is related to cognitive ability in early childhood using the UK Millennium Cohort Study.
Cognitive development was assessed using Bracken School Readiness Assessment at age 3 years, British Ability Scales II at ages 3, 5 and 7 years and Progress in Mathematics at age 7 years. Sample size varied according to outcome between 12 163 and 14 027. Each gestational age group was compared with the full-term group using differences in z-scores and risk ratios for scoring more than -1 SD below the mean.
Children born at <32 weeks gestation scored lower (P < 0.05) than the full-term group on all scales with unadjusted z-score differences ranging between -0.8 to -0.2 SD. In all groups, there was an increased risk (P < 0.05) of scoring less than -1 SD below the mean compared with the full-term group for some of the tests: those born at < 32 weeks had a 40-140% increased risk in seven tests, those born at 32-33 weeks had a 60-80% increased risk in three tests, those born at 34-36 weeks had a 30-40% increased risk in three tests, and those born at 37-38 weeks had a 20% increased risk in two tests.
Cognitive ability is related to the entire range of gestational age, including children born at 34-36 and 37-38 weeks gestation.
Preterm children are at greater risk for psychiatric disorders, including anxiety disorders and attention-deficit/hyperactivity disorder (ADHD), than their term-born peers. Prior research has focused primarily on children born at early gestational ages. Less is known about the rate of psychiatric disorders among late preterm or early term children. In addition, whether a history of maternal depression also associated with prematurity has an impact on the risk for psychiatric disorders remains underexplored.
Preschoolers between ages 3 and 6 years (N = 306) were recruited for a study examining preschool depression that included healthy and disruptive preschoolers. Preschoolers were placed in the following groups: late preterm (34-36 weeks, n = 39), early term (37-39 weeks, n = 78), and full term (40-41 weeks, n = 154). DSM-IV psychiatric disorders were assessed via the Preschool Age Psychiatric Assessment. Maternal history of psychiatric disorders was assessed using the Family Interview for Genetic Studies.
Late preterm children had higher rates of any Axis I psychiatric diagnosis (odds ratio = 3.18, 95% confidence interval = 1.09-4.76) and of any anxiety disorder (odds ratio = 3.74, 95% confidence interval = 1.59-8.78) than full term children after adjusting for gender, ethnicity, family income, and IQ. There were no differences in rates of psychiatric diagnoses between early term and full term children. A history of maternal depression mediated the relationship between late preterm birth and anxiety disorders in preschoolers.
Late preterm children were at increased risk for anxiety disorders at preschool age. A history of maternal depression mediated this association. Findings confirm the extension of the risk of psychiatric disorders associated with prematurity to the late preterm group, and suggest that maternal depression may play a key role in this risk trajectory.
In case-control studies that assess associations between medication use and birth defects, detailed information on type of medication and timing of use is essential to prevent misclassification. However, data on the accuracy of recall of medication use during pregnancy are scarce.
The aim of this study was to validate a self-administered questionnaire to assess prescription medication use in the 3 months before and during pregnancy.
This validation study was embedded in Eurocat Northern Netherlands, a population-based birth defects registry that covers 10 % of all births in The Netherlands. The questionnaire was validated among 560 mothers of infants with major birth defects registered from 1 January 2009 through 30 June 2010 by comparing it with a reference standard consisting of pharmacy data which were checked for compliance by maternal interviews. Sensitivity and specificity were calculated to quantify validity for any prescription medication use, groups of medications and individual medications. In addition, we determined whether maternal characteristics influenced disagreement between the questionnaire and the reference standard using logistic regression analyses.
The sensitivity for any prescription medication use was 0.57, ranging between 0.07 (dermatological corticosteroids) and 0.83 (antihypertensives) for medication groups, and between 0.00 (naproxen) and 0.73 (salbutamol) for individual medications. Overall, specificity was high (0.93-1.00). Smoking during pregnancy and completing the questionnaire >2 years after delivery were associated with increased disagreement between the questionnaire for prescription medication use and the reference standard.
The validity of the self-administered questionnaire for prescription medication use during pregnancy was moderate to poor for most medications and disagreement differed by some maternal characteristics. As many epidemiological studies use similar questionnaires to assess medication use these studies may need additional data sources such as pharmacy records or prescription databases for medication use next to self-reported methods. Also, previous knowledge on the effect of questionnaire design should be taken into account.
To investigate the burden of later disease associated with moderate/late preterm (32-36 weeks) and early term (37-38 weeks) birth.
Secondary analysis of data from the Millennium Cohort Study (MCS).
Longitudinal study of infants born in the United Kingdom between 2000 and 2002.
18,818 infants participated in the MCS. Effects of gestational age at birth on health outcomes at 3 (n = 14,273) and 5 years (n = 14,056) of age were analysed.
Growth, hospital admissions, longstanding illness/disability, wheezing/asthma, use of prescribed drugs, and parental rating of their children's health.
Measures of general health, hospital admissions, and longstanding illness showed a gradient of increasing risk of poorer outcome with decreasing gestation, suggesting a "dose-response" effect of prematurity. The greatest contribution to disease burden at 3 and 5 years was in children born late/moderate preterm or early term. Population attributable fractions for having at least three hospital admissions between 9 months and 5 years were 5.7% (95% confidence interval 2.0% to 10.0%) for birth at 32-36 weeks and 7.2% (1.4% to 13.6%) for birth at 37-38 weeks, compared with 3.8% (1.3% to 6.5%) for children born very preterm (<32 weeks). Similarly, 2.7% (1.1% to 4.3%), 5.4% (2.4% to 8.6%), and 5.4% (0.7% to 10.5%) of limiting longstanding illness at 5 years were attributed to very preterm birth, moderate/late preterm birth, and early term birth.
These results suggest that health outcomes of moderate/late preterm and early term babies are worse than those of full term babies. Additional research should quantify how much of the effect is due to maternal/fetal complications rather than prematurity itself. Irrespective of the reason for preterm birth, large numbers of these babies present a greater burden on public health services than very preterm babies.
To compare school performance at age 5 years in children born at full term (39-41 weeks gestation) with those born at early term (37-38 weeks gestation), late preterm (34-36 weeks gestation), moderately preterm (32-33 weeks gestation) and very preterm (<32 weeks gestation).
Population-based cohort (UK Millennium Cohort Study).
Seven thousand six hundred and fifty children born in 2000-2001 and attending school in England in 2006.
School performance was measured using the foundation stage profile (FSP), a statutory assessment by teachers at the end of the child's first school year. The FSP comprises 13 assessment scales (scored from 1 to 9). Children who achieve an average of 6 points per scale and at least 6 in certain scales are classified as 'reaching a good level of overall achievement'.
Fifty-one per cent of full term children had not reached a good level of overall achievement; this proportion increased with prematurity (55% in early term, 59% in late preterm, 63% in moderately preterm and 66% in very preterm children). Compared with full term children, an elevated risk remained after adjustment, even in early term (adjusted RR 1.05, 95% 1.00 to 1.11) and late preterm children (adjusted RR 1.12, 95% CI 1.04 to 1.22). Similar effects were noted for 'not working securely' in mathematical development, physical development and creative development. The effects of late preterm and early term birth were small in comparison with other risk factors.
Late preterm and early term birth are associated with an increased risk of poorer educational achievement at age 5 years.
As perinatal events have been linked with diseases of later onset, epidemiological studies on child development and adult
health require information on the perinatal period. When national neonatal registers do not exist, review of medical records
may be impractical. However, neonatal information could be obtained by asking mothers to complete a postal questionnaire using
data from the Personal Child Health Record (PCHR). We assessed agreement between medical records and mothers’ reports for
information on delivery and the newborn’s condition at birth, based on the PCHR, a short time after delivery. Of 711 women
giving birth in 3 French hospitals and invited to participate in the study, 580 (82%) completed a postal questionnaire 6weeks
after delivery, copying the data recorded in the PCHR when available. Information on pregnancy, delivery and the newborn’s
health at birth was independently extracted from medical records by physicians of the maternity departments. Agreement between
medical records and maternal reports for a range of perinatal factors was assessed in 580 newborn-mother dyads using kappa
coefficients. Agreement was excellent for first and second stages of delivery, gestational age, birth weight, birth size and
head circumference (kappa coefficients 0.80–1.00) and good for hospitalization during pregnancy, but poor for Apgar scores.
With this exception, mothers’ reports appeared reliable when compared with medical records. As PCHRs exist in most developed
countries, this approach could be used in epidemiological studies on child development to increase the reliability of mothers’
reports of their newborn’s condition at birth.
To compare healthy late-preterm infants with their full-term counterparts from age 4 through 15 years for numerous standard cognitive, achievement, socioemotional, and behavioral outcomes.
Prospective cohort study.
National Institute of Child Health and Development Study of Early Child Care and Youth Development, 1991-2007.
A total of 1298 children (53 born at 34-36 weeks' gestational age), and their families, observed from birth through age 15 years. None of the infants had major health problems before or immediately following birth, and all the infants were discharged from the hospital within 7 days.
Preterm status: children born late preterm (34-36 weeks) vs those born full term (37-41 weeks).
Eleven standard outcomes measuring cognition, achievement, social skills, and behavioral/emotional problems using the Woodcock-Johnson Psycho-Educational Battery-Revised and the Child Behavior Checklist, administered repeatedly through age 15 years.
No consistent significant differences were found between late-preterm and full-term children for these standard measures from ages 4 to 15 years. Through age 15 years, the mean difference of most of these outcomes hovered around 0, indicating, along with small confidence intervals around these differences, that it is unlikely that healthy late-preterm infants are at any meaningful disadvantage regarding these measures.
Late-preterm infants born otherwise healthy seem to have no real burdens regarding cognition, achievement, behavior, and socioemotional development throughout childhood.
The cognitive and behavioral outcomes of school-aged children who were born preterm have been reported extensively. Many of these studies have methodological flaws that preclude an accurate estimate of the long-term outcomes of prematurity.
To estimate the effect of preterm birth on cognition and behavior in school-aged children.
MEDLINE search (1980 to November 2001) for English-language articles, supplemented by a manual search of personal files maintained by 2 of the authors.
We included case-control studies reporting cognitive and/or behavioral data of children who were born preterm and who were evaluated after their fifth birthday if the attrition rate was less than 30%. From the 227 reviewed studies, cognitive data from 15 studies and behavioral data from 16 studies were selected.
Data on population demographics, study characteristics, and cognitive and behavioral outcomes were extracted from each study, entered in a customized database, and reviewed twice to minimize error. Differences between the mean cognitive scores of cases and controls were pooled. Homogeneity across studies was formally tested using a general variance-based method and graphically using Galbraith plots. Linear meta-analysis regression models were fitted to explore the impact of birth weight and gestational age on cognitive outcomes. Study-specific relative risks (RRs) were calculated for the incidence of attention-deficit/hyperactivity disorder (ADHD) and pooled. Quality assessment of the studies was performed based on a 10-point scale. Publication bias was examined using Begg modified funnel plots and formally tested using the Egger weighted-linear regression method.
Among 1556 cases and 1720 controls, controls had significantly higher cognitive scores compared with children who were born preterm (weighted mean difference, 10.9; 95% confidence interval [CI], 9.2-12.5). The mean cognitive scores of preterm-born cases and term-born controls were directly proportional to their birth weight (R(2) = 0.51; P<.001) and gestational age (R(2) = 0.49; P<.001). Age at evaluation had no significant correlation with mean difference in cognitive scores (R(2) = 0.12; P =.20). Preterm-born children showed increases in externalizing and internalizing behaviors in 81% of studies and had more than twice the RR for developing ADHD (pooled RR, 2.64; 95% CI, 1.85-3.78). No differences were noted in cognition and behaviors based on the quality of the study.
Children who were born preterm are at risk for reduced cognitive test scores and their immaturity at birth is directly proportional to the mean cognitive scores at school age. Preterm-born children also show an increased incidence of ADHD and other behaviors.
The Millennium Cohort Study of UK babies born this century obtained maternal report of birth weight and data on the family's characteristics, including parental ethnicity, education, and social circumstances. Parental permission to link babies to their birth registration data provided the opportunity to investigate factors affecting accuracy of maternal recall of birth weight and to determine possible causes of error.
Logistic regression was used to investigate the relationship between maternal factors and recall of birth weight. Numerical and graphical methods were used to identify potential causes for birth weight discrepancies.
Data were obtained from the birth registry and Millennium Cohort Study for 11 890 of the 14 294 cohort children born in England and Wales. Weight was reported in imperial units by 84% of mothers and this was more common in younger mothers. Accuracy within 100 g was 92% overall, varying from 94% among British/Irish white mothers to 69-89% for other ethnic groups and was lower among the long-term unemployed and those living in disadvantaged or ethnic wards. Explanations (mostly rounding and transcription errors) were identified for 27% of the discrepancies of 100 g or more. Conclusion Mothers' reports of their infants' birth weight showed high level of agreement with registration data, the mean discrepancy being consistently close to zero. However, the variance of the discrepancy differed according to ethnic group, ward type, and socioeconomic status. These sources of differential variability should be taken into account in analyses using birth weight, and possibly other reported data, from socially mixed populations.
The Millennium Cohort Study of 18 818 UK babies born in 2000–02 interviewed parents when the baby was 9 months old. Time constraints on the interview limited the amount of health‐related questions that could be included. The aim of this study was to augment interview data with information from birth registrations and hospital records. It also provided an opportunity to assess the accuracy of the data acquired and parents' recall of the information on pregnancy and delivery. Deterministic and probabilistic matching were used to obtain information from birth registration and hospital records. Investigation into the accuracy of the matches obtained was undertaken. The records received were checked for range, consistency and completion.
Birth registration data were obtained for 99% of those who gave consent. The number of additional variables gained ranged from six in Northern Ireland to 16 in Scotland. Hospital record data were obtained for 83% of those who gave consent. The additional general and maternity‐related variables gained ranged from 55 in Scotland to 76 in England. Completion of available health record variables ranged from 28% to 100% across all UK countries. Linkage to birth registration and hospital records in order to augment Millennium Cohort Study data with routinely collected data was successful. The variables gained by linkage have added considerable value to the cohort study and validated some of the mother's responses.
Centile charts of birthweight for gestational age are used to identify low birthweight babies. The charts currently used in Scotland are based on data from the 1970s and require updating given changes in birthweight and in the measurement of gestational age since then.
Routinely collected data of 100,133 singleton births occurring in Scotland from 1998-2003 were used to construct new centile charts using the LMS method.
Centile charts for birthweight for sex and parity groupings were constructed for singleton birth and compared to existing charts used in Scottish hospitals.
Mean birthweight has been shown to have increased over recent decades. The differences shown between the new and currently used centiles confirm the need for more up-to-date centiles for birthweight for gestational age.
Context
The World Health Organization defines preterm birth as birth at less
than 37 completed gestational weeks, but most studies have focused on very
preterm infants (birth at <32 weeks) because of their high risk of mortality
and serious morbidity. However, infants born at 32 through 36 weeks are more
common and their public health impact has not been well studied.Objective
To assess the quantitative contribution of mild (birth at 34-36 gestational
weeks) and moderate (birth at 32-33 gestational weeks) preterm birth to infant
mortality.Design, Setting, and Participants
Population-based cohort study using linked singleton live birth–infant
death cohort files for US birth cohorts for 1985 and 1995 and Canadian birth
cohorts (excluding Ontario) for 1985-1987 and 1992-1994.Main Outcome Measures
Relative risks (RRs) and etiologic fractions (EFs) for overall and cause-specific
early neonatal (age 0-6 days), late neonatal (age 7-27 days), postneonatal
(age 28-364 days), and total infant death among mild and moderate preterm
births vs term births (at ≥37 gestational weeks).Results
Relative risks for infant death from all causes among singletons born
at 32 through 33 gestational weeks were 6.6 (95% confidence interval [CI],
6.1-7.0) in the United States in 1995 and 15.2 (95% CI, 13.2-17.5) in Canada
in 1992-1994; among singletons born at 34 through 36 gestational weeks, the
RRs were 2.9 (95% CI, 2.8-3.0) and 4.5 (95% CI, 4.0-5.0), respectively. Corresponding
EFs were 3.2% and 4.8%, respectively, at 32 through 33 gestational weeks and
6.3% and 8.0%, respectively, at 34 through 36 gestational weeks; the sum of
the EFs for births at 32 through 33 and 34 through 36 gestational weeks exceeded
those for births at 28 through 31 gestational weeks. Substantial RRs were
observed overall for the neonatal (eg, for early neonatal deaths, 14.6 and
33.0 for US and Canadian infants, respectively, born at 32-33 gestational
weeks; EFs, 3.6% and and 6.2% for US and Canadian infants, respectively) and
postneonatal (RRs, 2.1-3.8 and 3.0-7.0 for US and Canadian infants, respectively,
born at 32-36 gestational weeks; EFs, 2.7%-5.8% and 3.0%-7.0% for the same
groups, respectively) periods and for death due to asphyxia, infection, sudden
infant death syndrome, and external causes. Except for a reduction in the
RR and EF for neonatal mortality due to infection, the patterns have changed
little since 1985 in either country.Conclusions
Mild– and moderate–preterm birth infants are at high RR
for death during infancy and are responsible for an important fraction of
infant deaths.
The World Health Organization defines preterm birth as a gestational
age at birth of less than 37 completed gestational weeks.1
Preterm birth is recognized as a major public health problem by both clinicians
and researchers because it is the leading cause of infant mortality in industrialized
countries and also contributes to substantial neurocognitive, pulmonary, and
ophthalmologic morbidity.2- 5
Caring for preterm infants also incurs large health care expenditures.6 Most studies of morbidity and mortality among preterm
infants have focused on those born very preterm, ie, at gestational ages less
than 32 weeks.7- 17
For infants born at 32 through 36 gestational weeks, the risks are much lower,
especially with recent advances in neonatal intensive care.7,16
On the other hand, from a public health perspective, births at gestational
ages of 32 through 36 weeks are much more common than those at less than 32
gestational weeks.7,18 Thus it
is important to distinguish absolute risk both from relative risk (RR) and
from public health impact (ie, etiologic fraction [EF]).
The RR indicates how much more frequently a given outcome occurs in
persons with vs those without a risk factor. The EF is the proportion of all
cases of the outcome occurring in a given population that can be attributed
to exposure to the risk factor; it is sometimes referred to as the population-attributable
risk.19 Because the EF is a function of both
the RR and the population prevalence of exposure to the risk factor, common
risk factors account for much higher EFs than do rare risk factors. For example,
an anomalous coronary artery is associated with a very high RR of myocardial
infarction but (owing to its extreme rarity) a very low EF. By contrast, cigarette
smoking, which is highly prevalent, accounts for an appreciable portion of
myocardial infarctions despite its modestly elevated RR.
We hypothesized that mild and moderate preterm births, which we define
as live births at 34 through 36 and 32 through 33 completed weeks of gestation,
respectively, are associated with an increased risk of infant mortality relative
to term births. We further hypothesized that mild and moderate preterm births
account for an important fraction of infant deaths. In particular, we suspected
that the increased RRs and substantial EFs for infant death would be most
pronounced for specific groups of causes (infection, sudden infant death syndrome
[SIDS], and external causes such as unintentional injuries and abuse) and
would be concentrated in the postneonatal rather than the neonatal period.
Finally, we hypothesized that these increased risks would be observed in both
the United States and Canada and would have diminished only slightly over
time.
Evidence on the validity of parental recall of early childhood behavior is lacking. Our aim was to examine the validity of parental recall at child age 10-12 years for maternal lifestyle during pregnancy, the birth characteristics, and early childhood behavior.
The study population comprised 2,230 children and their parents. Children aged 10-12 years were recruited from elementary schools (response: 76.0%). Parents were asked to recall lifestyle during pregnancy, birth characteristics, and childhood behavior at age 4-6 years. Recalled data were compared with information registered by Preventive Child Healthcare (PCH) from birth onwards.
For birth weight and gestational age, we found no systematic difference between recalled and PCH-registered data; 95% limits of agreement were + or - 1.2 pounds (600 g) and + or - 2.4 weeks, respectively. For maternal alcohol use during pregnancy and early childhood behavior problems, Cohen's kappas were low (0.03-0.11). Compared with PCH registration, parents tended to overreport at age 10-12 years. In contrast, kappa was high for maternal smoking during pregnancy (0.77).
Retrospectively collected information on lifestyle during pregnancy, birth, and early childhood behavior is sometimes biased, which limits its value in estimating the contribution of early-life adversity to health in later life.
To determine the analytic advantages obtained from separating unmarried mothers with partners from unmarried mothers without partners when assessing risk of adverse birth outcomes.
Data were obtained from Listening to Mothers II, a national survey of women's childbearing experiences. Marital status was asked with three choices: married (71%), unmarried with partner (24%), and unmarried without partner (5%). Demographic differences between the three marital status groups were compared using chi (2) tests. Multiple logistic regressions, controlling for age, education, race/ethnicity, and parity, tested for associations between birth outcomes (birth weight and gestational age) and marital status.
Unmarried mothers with partners and without partners were similar in age, education, and parity. Unmarried mothers without partners delivered by cesarean more often (39%) and were more likely to have a doctor as birth attendant (99%) than unmarried mothers with partners. The multiple logistic regressions indicated that, compared to married mothers, unmarried mothers with partners had the same risk of premature infants, while unmarried mothers without partners had greater risk. Unmarried first-time mothers with partners had over twice the risk of premature infants (OR = 2.71; 1.07-6.85) and unmarried mothers without partners had over 5 times the risk (OR = 5.64; 1.68-18.92) when compared to married first-time mothers.
Mothers without partners were at higher risk than unmarried mothers with partners indicating a gradient of risk. Future data collection on marital status should consider distinguishing between unmarried mothers with and without partners.
Agreement between maternal interview- and medical record-based gestational age was assessed by using data from a case-control study of childhood strabismus. The sample consisted of 383 cases of strabismus and their age-matched controls, diagnosed between 1985 and 1986 in Baltimore, Maryland, who were under age 7 years when diagnosed. Medical record-based gestational age was derived, in order of priority, from early ultrasound examination, time from the last menstrual period, pediatric examination, and obstetric examination. The intraclass correlation coefficient, kappa, and mean difference were used to compare agreement between maternal interview- and medical record-based gestational age by maternal and pregnancy characteristics and characteristics related to study design. Overall, 86 percent of mothers were within 2 weeks of the gestational age reported in the medical record. The intraclass correlation coefficient comparing maternal and medical record-based gestational age was 0.83 (95% confidence interval 0.80-0.86). Agreement was positively associated with shorter length of recall, low birth order, and having a neonatal illness related to prematurity. Agreement was poor among mothers of healthy preterm infants. There was a weak positive association between recall and some sociodemographic covariates. There was greater misclassification of prematurity in the controls than in the cases. The results suggest that, in general, women recall gestational age well, which supports the use of gestational age derived from maternal interviews.
Epidemiologic studies frequently obtain exposure information through subjects' self-report (personal interview or mailed questionnaire). The authors used data from a case-control study of infant leukemia, to assess the validity and reliability of maternally reported information on birth characteristics such as birth weight, reproductive history, and medical procedures. Cases were gathered from the Children's Cancer Group, a United States and Canadian cooperative clinical trails group with approximately 100 member and affiliate institutions, during 1983-1988. Telephone interviews were completed for 302 cases and 558 matched controls. Medical records of the index pregnancy were obtained for 287 cases and 467 controls. Correlations between medical charts and maternal interview were high for birth weight (r = 0.98, kappa = 0.9) and gestational age (r = 0.86, kappa = 0.6). Mean differences between the two sources were small, -10.5 g for birth weight and -0.36 weeks for gestational age. Reproductive history and medical procedures had high to moderate reliability. Problems after delivery and pregnancy complications generally had low validity and reliability. Little evidence of differential misclassification was found. Time between delivery and interview ranged from zero to 8 years and did not greatly affect reliability. This study suggests that validity and reliability of maternally reported pregnancy and delivery information may differ with the nature of the factor of interest, but is affected little by time from birth or case-control status.
Women themselves are often the most convenient source of information regarding their pregnancy and birth outcomes such as prematurity. However, the ability of mothers to recall birth information and the accuracy of information they do recall has rarely been assessed. This study used a mail survey of women who delivered either term or preterm infants in Rochester, Minnesota, between 1980 and 1985. Maternal reports of circumstances and outcome of delivery were compared to data abstracted from the medical records. Maternal ability to recall and report events varied from 99.5% for smoking during pregnancy to 85% for infant's gestational age at birth. Agreement between medical record and maternal report was very high for perinatal events such as delivery by cesarean section, preexisting diabetes, and smoking. Percent negative agreement was quite high when comparing information on rare events such as placental abruption. Recall of gestational age was better for women delivering preterm infants but uncommon in all women. Maternal reports of perinatal events in which they directly participated such as cesarean section can be accurately and reliably reported 10 to 15 years after the birth. Gestational age is reported less accurately and with different rates of recall for mothers with term and preterm deliveries.
Agreement between two methods of clinical measurement can be quantified using the differences between observations made using the two methods on the same subjects. The 95% limits of agreement, estimated by mean difference +/- 1.96 standard deviation of the differences, provide an interval within which 95% of differences between measurements by the two methods are expected to lie. We describe how graphical methods can be used to investigate the assumptions of the method and we also give confidence intervals. We extend the basic approach to data where there is a relationship between difference and magnitude, both with a simple logarithmic transformation approach and a new, more general, regression approach. We discuss the importance of the repeatability of each method separately and compare an estimate of this to the limits of agreement. We extend the limits of agreement approach to data with repeated measurements, proposing new estimates for equal numbers of replicates by each method on each subject, for unequal numbers of replicates, and for replicated data collected in pairs, where the underlying value of the quantity being measured is changing. Finally, we describe a nonparametric approach to comparing methods.
Obtaining information on children's health and health events is heavily dependent on maternal report. Experience as to what factors influence accuracy of reporting varies, and few studies have examined the influence of current child health status on recall.
A prospective cohort study involving 1833 children who were assessed in infancy and at 8 to 10 years of age was conducted to assess maternal reports of birth weight, gestational age, neonatal transport, length of neonatal hospitalization, and rehospitalizations in the first year compared with data collected in infancy overall, and as a function of concurrent child functional health status, socioemotional health, and ratings of child health.
Maternal recall of neonatal events was accurate but not that of rehospitalizations in the first year. Concurrent child health problems affected accuracy but not sufficiently to make information unusable.
Maternal recall of neonatal events 8 to 10 years later is accurate; however, the influence of current child health status on recall may be important in research on the cognitive processes underlying health questionnaire responses.
The World Health Organization defines preterm birth as birth at less than 37 completed gestational weeks, but most studies have focused on very preterm infants (birth at <32 weeks) because of their high risk of mortality and serious morbidity. However, infants born at 32 through 36 weeks are more common and their public health impact has not been well studied.
To assess the quantitative contribution of mild (birth at 34-36 gestational weeks) and moderate (birth at 32-33 gestational weeks) preterm birth to infant mortality.
Population-based cohort study using linked singleton live birth-infant death cohort files for US birth cohorts for 1985 and 1995 and Canadian birth cohorts (excluding Ontario) for 1985-1987 and 1992-1994.
Relative risks (RRs) and etiologic fractions (EFs) for overall and cause-specific early neonatal (age 0-6 days), late neonatal (age 7-27 days), postneonatal (age 28-364 days), and total infant death among mild and moderate preterm births vs term births (at >/=37 gestational weeks).
Relative risks for infant death from all causes among singletons born at 32 through 33 gestational weeks were 6.6 (95% confidence interval [CI], 6.1-7.0) in the United States in 1995 and 15.2 (95% CI, 13.2-17.5) in Canada in 1992-1994; among singletons born at 34 through 36 gestational weeks, the RRs were 2.9 (95% CI, 2.8-3.0) and 4.5 (95% CI, 4.0-5.0), respectively. Corresponding EFs were 3.2% and 4.8%, respectively, at 32 through 33 gestational weeks and 6.3% and 8.0%, respectively, at 34 through 36 gestational weeks; the sum of the EFs for births at 32 through 33 and 34 through 36 gestational weeks exceeded those for births at 28 through 31 gestational weeks. Substantial RRs were observed overall for the neonatal (eg, for early neonatal deaths, 14.6 and 33.0 for US and Canadian infants, respectively, born at 32-33 gestational weeks; EFs, 3.6% and and 6. 2% for US and Canadian infants, respectively) and postneonatal (RRs, 2.1-3.8 and 3.0-7.0 for US and Canadian infants, respectively, born at 32-36 gestational weeks; EFs, 2.7%-5.8% and 3.0%-7.0% for the same groups, respectively) periods and for death due to asphyxia, infection, sudden infant death syndrome, and external causes. Except for a reduction in the RR and EF for neonatal mortality due to infection, the patterns have changed little since 1985 in either country.
Mild- and moderate-preterm birth infants are at high RR for death during infancy and are responsible for an important fraction of infant deaths. JAMA. 2000;284:843-849
Adverse obstetric events have been implicated as risk factors for schizophrenia. Many studies have relied on retrospective recall of these events, given typical adult onset of schizophrenia, when most studies ascertain their samples. The goal of this study was to assess the validity of an interview for the long-term recall of prenatal and perinatal events. Ninety-six women from the Providence and Boston cohorts of the National Collaborative Perinatal Project were administered a brief structured telephone interview regarding their recall of pregnancy-related events that had occurred 22 years or more prior to interview. Women accurately reported major medical events such as cesarean section, breech delivery, and multiple birth (kappa=1) and demographic items, such as age at birth and parity. Medical interventions and major medical conditions such as placental (kappa=-0.01) and cord (kappa=-0.10) difficulties were not accurately reported. Estimated birthweight, low birthweight, and length of gestation were recalled with reasonable accuracy. Women who completed high school generally recalled events more accurately than those who did not. It is therefore important to attend to the sources of information, the mode of interviewing, the specific type of event, and sociodemographic characteristics of the informant to improve the accuracy of retrospective data on obstetric events, and to increase the validity of findings relating these to the onset of schizophrenia.
The increased use of computer-based records has facilitated linkage of routine data with that obtained for research. When children are involved, parental consent for linkage is usually required. The Millennium Cohort Study, of 18,819 UK babies born in 2000-02, over-sampled families from disadvantaged and ethnic wards, providing the opportunity to investigate factors associated with mother's consent to access her child's birth records.
Factors considered included ward type and mother's socioeconomic status, ethnicity, education, age, and language. Logistic regression was used to investigate the relationship of these factors with consent.
Consent for linkage to birth register and/or hospital maternity data was obtained from 92% of the cohort mothers. The proportions consenting differed according to the mother's country of residence, age, and education, with consent being less likely among minority ethnic group mothers, lone parents, and those with higher degrees or no qualifications. Where interviews had been translated, consent was significantly less likely if the interpreter was a male.
A large proportion of mothers who were interviewed gave permission for linkage. However, there were some groups who were less likely to do so, particularly those from minority ethnic groups. These sources of non-consent bias should be taken into account when analysing linked data from socially and ethnically mixed populations. Efforts should be made to understand the reasons for non-consent, which in turn will help determine the best ways to encourage more mothers to consent in future.
This study examined the accuracy of maternal recall of obstetric complications and birth characteristics and its determinants for both preterm and term deliveries 3-9 years ago.
In 101 preterm and 107 term deliveries at the National Taiwan University Hospital during 1995-2000, recall data were obtained by telephone interview with the mothers and were matched with medical records.
Among 10 obstetric complications assessed, the accuracy of maternal recall could either have high sensitivity and high specificity (Cesarean section, gestational hypertension, and induced labor), low to moderate sensitivity and high specificity (pre-eclampsia, breech, and cord loops), or low sensitivity and low specificity (ante partum vaginal bleeding, edema, and proteinuria). The correlations between maternal recall and medical records for birth weight (r = .95) and gestational age (r =.93) in the preterm group were slightly higher than those in the term group (r = .89 and .83, respectively). Factors associated with higher recall accuracy included preterm delivery, first birth order, and lower total parity, but no factor consistently related to maternal accuracy for all obstetric complications and birth characteristics.
The accuracy of maternal recall on obstetric complications varied depending on the nature of complications examined, whereas that on birth characteristics was high.
To determine the accuracy of maternal recall of children birthweight (BW) and gestational age (GA), using the Danish Medical Birth Register (DBR) as reference and to examine the reliability of recalled BW and its potential correlates.
Comparison of data from the DBR and the European Youth Heart Study (EYHS).
Schools in Odense, Denmark.
A total of 1271 and 678 mothers of school children participated with information in the accuracy studies of BW and GA, respectively. The reliability sample of BW was composed of 359 women.
The agreement between the two sources was evaluated by mean differences (MD), intraclass correlation coefficient (ICC) and Bland-Altman's plots. The misclassification of the various BW and GA categories were also estimated.
Differences between recalled and registered BW and GA.
There was high agreement between recalled and registered BW (MD =-0.2 g; ICC = 0.94) and GA (MD = 0.3 weeks; ICC = 0.76). Only 1.6% of BW would have been misclassified into low, normal or high BW and 16.5% of GA would have been misclassified into preterm, term or post-term based on maternal recall. The logistic regression revealed that the most important variables in the discordance between recalled and registered BW were ethnicity and parity. Maternal recall of BW was highly reliable (MD =-5.5 g; ICC = 0.93), and reliability remained high across subgroups.
Maternal recall of BW and GA seems to be sufficiently accurate for clinical and epidemiological use.
Because limited long-term outcome data exist for infants born at 32 to 36 weeks gestation, we compared school outcomes between 32- to 33-week moderate preterm (MP), 34-36 week late preterm (LP) and full-term (FT) infants.
A total of 970 preterm infants and 13 671 FT control subjects were identified from the Early Childhood Longitudinal Study-Kindergarten Cohort. Test scores, teacher evaluations, and special education enrollment from kindergarten (K) to grade 5 were compared.
LP infants had lower reading scores than FT infants in K to first grade (P < .05). Adjusted risk for poor reading and math scores remained elevated in first grade (P < .05). Teacher evaluations of math skills from K to first grade and reading skills from K to fifth grade were worse for LP infants (P < .05). Adjusted odds for below average skills remained higher for math in K and for reading at all grades (P < .05). Special education participation was higher for LP infants at early grades (odds ratio, 1.4-2.1). MP infants had lower test and teacher evaluation scores than FT infants and twice the risk for special education at all grade levels.
Persistent teacher concerns through grade 5 and greater special education needs among MP and LP infants suggest a need to start follow-up, anticipatory guidance, and interventions for infants born at 32 to 36 weeks gestation.
Cogni-tive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis
- Cleves Ma Bhutta At
- Casey Ph Cradock Mm
- Anand
- Kj
Bhutta AT, Cleves MA, Casey PH, Cradock MM, Anand KJ. Cogni-tive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis. JAMA 2002;288:728e37.
Confidential Enquiry into Maternal and Child Health
Confidential Enquiry into Maternal and Child Health. Perinatal mortality 2005: England, Wales and Northern Ireland. London, UK:
CEMACH; 2007.
Millennium Cohort Study First Survey: technical report on sampling.
- Plewis I.
Plewis I. Millennium Cohort Study First Survey: technical report on
sampling. 4th ed. London, UK: Centre for Longitudinal Studies,
Institute of Education; 2007.
Measuring agreement in method comparison studies
- Bland
Bland JM, Altman DG. Measuring agreement in method comparison
studies. Stat Methods Med Res 1999 Jun;8(2):135e60.
Perinatal mortality 2005: England, Wales and Northern Ireland.
- Confidential Enquiry into Maternal and Child Health
NHS maternity statistics, England 1998-1999 to 2000-2002.
- Government Statistical Service