Paediatric and Perinatal Epidemiology (Paediatr Perinat Epidemiol)

Publications in this journal

• Article: Physical activity during pregnancy and language development in the offspring.

  Anne Marie Z Jukic, Debbie A Lawlor, Mette Juhl, Katrine M Owe, Barbara Lewis, Jihong Liu, Allen J Wilcox, Matthew P Longnecker
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  ABSTRACT: In rodents, physical activity during pregnancy has been associated with improved learning and memory in the offspring. We used data from the Avon Longitudinal Study of Parents and Children (born in 1991-92) to investigate maternal physical activity during pregnancy and offspring language development. At 18 weeks of gestation, women reported the hours per week they participated in 11 leisure-time physical activities and the hours per week spent in general physical activity (leisure, household and occupational). Caregivers completed a modified MacArthur Infant Communication scale at 15 months. Verbal intelligence quotient (IQ) was measured at age 8 years. Regression analysis was used to examine the associations of physical activity with MacArthur score (more than 75th percentile) and verbal IQ. The number of participants available for analyses ranged from 4529 to 7162. Children of women in the two highest quintiles of leisure activity (compared with no leisure activity) were more likely to have high 15-month MacArthur scores (adjusted odds ratio 1.2 [95% confidence interval 0.9, 1.4] and adjusted odds ratio 1.4 [95% CI 1.1, 1.7], respectively). Leisure activity was not associated with IQ, while general physical activity was linked with lower verbal IQ (1 and 3 points lower for the two highest quintiles). The most robust finding was a transient increase in offspring vocabulary score at young ages with maternal leisure activity. Differences in the associations with leisure-time physical activity compared with general physical activity need further exploration.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):283-93.
• Article: Pregnancy Recruitment for Population Research: the National Children's Study Vanguard Experience in Wayne County, Michigan.

  Jean Kerver, Michael Elliot, Gwendolyn Norman, Robert Sokol, Dan Keating, Glenn Copeland, Christine Johnson, Kendall Cislo, KH Alcser, SR Kruger-Ndiaye, Beth-Ellen Pennell, Shobha Mehta, Christine Joseph, Nigel Paneth
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  ABSTRACT: Abstract Background To obtain a probability sample of pregnancies, the National Children's Study conducted door-to-door recruitment in randomly selected neighbourhoods in randomly selected counties in 2009–10. In 2011, an experiment was conducted in 10 US counties, in which the two-stage geographic sample was maintained, but participants were recruited in prenatal care provider offices. We describe our experience recruiting pregnant women this way in Wayne County, Michigan, a county where geographically eligible women attended 147 prenatal care settings, and comprised just 2% of total county pregnancies. Methods After screening for address eligibility in prenatal care offices, we used a three-part recruitment process: (1) providers obtained permission for us to contact eligible patients, (2) clinical research staff described the study to women in clinical settings, and (3) survey research staff visited the home to consent and interview eligible women. Results We screened 34 065 addresses in 67 provider settings to find 215 eligible women. Providers obtained permission for research contact from 81.4% of eligible women, of whom 92.5% agreed to a home visit. All home-visited women consented, giving a net enrolment of 75%. From birth certificates, we estimate that 30% of eligible county pregnancies were enrolled, reaching 40–50% in the final recruitment months. Conclusions We recruited a high fraction of pregnancies identified in a broad cross-section of provider offices. Nonetheless, because of time and resource constraints, we could enrol only a fraction of geographically eligible pregnancies. Our experience suggests that the probability sampling of pregnancies for research could be more efficiently achieved through sampling of providers rather than households.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):303-311.
• Article: Cell phone exposures and hearing loss in children in the danish national birth cohort.

  Madhuri Sudan, Leeka Kheifets, Onyebuchi A Arah, Jorn Olsen
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  ABSTRACT: Children today are exposed to cell phones early in life, and may be the most vulnerable if exposure is harmful to health. We investigated the association between cell phone use and hearing loss in children. The Danish National Birth Cohort (DNBC) enrolled pregnant women between 1996 and 2002. Detailed interviews were conducted during gestation, and when the children were 6 months, 18 months and 7 years of age. We used multivariable-adjusted logistic regression, marginal structural models (MSM) with inverse-probability weighting, and doubly robust estimation (DRE) to relate hearing loss at age 18 months to cell phone use at age 7 years, and to investigate cell phone use reported at age 7 in relation to hearing loss at age 7. Our analyses included data from 52 680 children. We observed weak associations between cell phone use and hearing loss at age 7, with odds ratios and 95% confidence intervals from the traditional logistic regression, MSM and DRE models being 1.21 [95% confidence interval [CI] 0.99, 1.46], 1.23 [95% CI 1.01, 1.49] and 1.22 [95% CI 1.00, 1.49], respectively. Our findings could have been affected by various biases and are not sufficient to conclude that cell phone exposures have an effect on hearing. This is the first large-scale epidemiologic study to investigate this potentially important association among children, and replication of these findings is needed.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):247-57.
• Article: Maternal smoking during pregnancy and failure of the georgia first grade criterion-referenced competency test.

  Jia Feng, Michael R Kramer, Bridget V Dever, Anne L Dunlop, Bryan Williams, Lucky Jain
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  ABSTRACT: Maternal smoking during pregnancy (MSDP) has been reported to be associated with impaired measures of cognitive function, but it remains unclear whether exposure to MSDP has an impact upon offspring school performance. We examined the association between MSDP and failure of the Criterion-Referenced Competency Tests (CRCT) among Georgia first grade students. A retrospective cohort was created by deterministically linking 331 531 children born in Georgia from 1998 to 2002 (inclusive) to their individual CRCT education records from 2005 to 2009. We evaluated the association between MSDP (yes/no) and failure of the CRCT Reading, English/Language Arts (ELA), and Mathematics tests, with adjustment for maternal and child sociodemographic characteristics and birth outcomes. Log-binomial models estimated the risk ratios and 95% confidence intervals. Conditional models were fitted to paired sibling data. MSDP was associated with CRCT failure with an adjusted risk ratios for Reading: 1.16 [95% CI 1.12, 1.21]; ELA: 1.12 [95%CI 1.10, 1.15]; and Mathematics: 1.13 [95%CI 1.10, 1.16]. The association remained significant in paired sibling analyses. MSDP may have independent long-term effects on offspring school performance, which does not appear to be through smoking-related adverse birth outcomes.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):275-82.
• Article: Maternal stress/distress, hormonal pathways and spontaneous preterm birth.

  Michael S Kramer, John Lydon, Lise Goulet, Susan Kahn, Mourad Dahhou, Robert W Platt, Shakti Sharma, Michael J Meaney, Louise Séguin
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  ABSTRACT: Although second-trimester blood corticotrophin-releasing hormone (CRH) levels are robustly associated with preterm birth, the findings with respect to cortisol have been inconsistent, as have been those relating stress hormones to measured stressors and maternal distress. We measured plasma CRH, adrenocorticotrophic hormone (ACTH), cortisol, cortisol-binding globulin, oestradiol and progesterone at 24-26 weeks in a nested case-control study of 206 women who experienced spontaneous preterm birth and 442 term controls. We also related the hormonal levels to measures of environmental stressors, perceived stress and maternal distress (also assessed at 24-26 weeks) and to placental histopathology. With the exception of an unexpectedly low oestradiol : progesterone ratio among cases (adjusted odds ratio = 0.5 [95% confidence interval 0.3, 0.8] for ratios above the median in controls), none of the hormonal measures was independently associated with spontaneous preterm birth; placental histopathological evidence of infection/inflammation, infarction or decidual vasculopathy; or measures of maternal stress or distress. CRH levels were positively associated with cortisol, but not with ACTH, whereas ACTH was also positively associated with cortisol. Our findings suggest an intact pituitary-adrenal axis and confirm the positive feedback effect of cortisol on (placental) CRH. Neither of these hormonal pathways, however, was strongly linked to maternal stress/distress or to the risk of spontaneous preterm birth.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):237-46.
• Article: Smoking during Pregnancy and Risk of Autism Spectrum Disorder in a Finnish National Birth Cohort.

  Phuong Lien Tran, Venla Lehti, Katja M Lampi, Hans Helenius, Auli Suominen, Mika Gissler, Alan S Brown, Andre Sourander
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  ABSTRACT: Results of previous population-based studies examining associations between smoking during pregnancy and autism spectrum disorders (ASD) are contradictory. Furthermore, there is a lack of population-based studies examining the relationship between smoking during pregnancy and the main diagnostic subtypes of ASD. We conducted a population-based nested case-control study based on the Finnish Prenatal Study of Autism (FIPS-A) among liveborn infants delivered in Finland between 1987 and 2005. Data on maternal smoking during pregnancy were available from the Finnish Medical Birth Register (FMBR) since October 1990. Data on ASD in the offspring were obtained from the Finnish Hospital Discharge Register (FHDR). Among the three subtypes of ASD, maternal smoking during the whole pregnancy was associated with an increased risk of pervasive developmental disorder (PDD) (odds ratio 1.2, 95% confidence interval 1.0, 1.5). The increase in odds persisted after controlling for maternal age, mother's socio-economic and psychiatric status, and infant's weight for gestational age. However, smoking exposure limited to the first trimester was not associated with PDD or any of the other ASD subtypes. Maternal smoking is related to a modest increase in risk of PDD, while no associations were observed for childhood autism and Asperger's syndrome.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):266-74.
• Article: Moving forward: a new associate editor for paediatric and child health epidemiology.

  Cande V Ananth
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):227.
• Article: The exposome - exciting opportunities for discoveries in reproductive and perinatal epidemiology.

  Germaine M Buck Louis, Edwina Yeung, Rajeshwari Sundaram, S Katherine Laughon, Cuilin Zhang
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  ABSTRACT: Understanding the mechanisms that underlie successful human reproduction and development is an ambitious goal, given the many unique methodological challenges surrounding such study. These challenges are well understood by reproductive and perinatal epidemiologists and include its conditional nature, unobservable yet informative outcomes such as conception, multi-scale missing data, correlated or non-independent outcomes, interval censoring and a hierarchical data structure. Novel methodologies for overcoming these challenges and for answering critical data gaps are needed if we are to better understand the inefficiency that currently characterises human reproduction with the goal of improving population health. The exposome is an emerging paradigm that offers promise for understanding the natural history of human reproduction and development, and its many associated impairments that develop later in child- or adulthood. This novel paradigm recognises the need to identify and measure the totality of environmental (non-genetic) exposures from preconception through sensitive windows, and to identify patterns associated with healthy and adverse outcomes. The exposome accommodates research focusing on unique subpopulations, such as couples undergoing assisted reproductive technologies, so that methodological limitations such as unobservable and conditional outcomes can be better addressed. Reproductive and perinatal epidemiology is uniquely suited for proof-of-concept exposome research, given the intricate relations between fecundity, gravid health and later onset disease and the narrow and interrelated sensitive windows that characterise the conditional nature of human reproduction and development. Bold new conceptual frameworks such as the exposome are needed for designing research that may lead to discovery and improve population health.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):229-36.
• Article: Direct and proxy recall of childhood socio-economic position and health.

  Jennifer K Straughen, Cleopatra H Caldwell, Theresa L Osypuk, Laura Helmkamp, Dawn P Misra
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  ABSTRACT: The utility of proxy reporting within the life course framework has not been adequately assessed; therefore we sought to assess the magnitude and type of agreement that exists between index and proxy reports for bodyweight, health, and socio-economic position (SEP) in childhood. Participants were enrolled as part of an ongoing study of preterm birth in African American women in Metro Detroit. Post-partum women and their mothers (n = 333 pairs) provided retrospective reports about the woman's childhood bodyweight, health, and SEP. Agreement was assessed using kappa, weighted kappa (κ), and intraclass correlation coefficients (ICC). Log-linear models were used to describe the pattern of agreement for ordinal data. Birthweight and weight at age 18 was reported with a high level of agreement (ICC = 0.86 and 0.71, respectively). Kappa indicated moderate agreement for early and late childhood/adolescent weight. Log-linear models suggested that there was diagonal agreement plus linear by linear association for early childhood weight and linear by linear association in late childhood/adolescence. Reports of childhood medical problems and hospitalisations had only moderate agreement. Agreement for SEP in both early (κ = 0.14) and late childhood/adolescence (κ = 0.20) was poor. Log-linear models suggest a linear by linear association, indicating a positive association between the responses. Results suggest that proxy reports may be utilised in conjunction with an index report to provide an estimate of the accuracy of report or to more fully capture experiences over the life course. This may be particularly useful when multiple developmental periods are examined.
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):294-302.
• Article: Current vision and future directions.

  Kenneth C Schoendorf
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):228.
• Article: A time and place for causal inference methods in perinatal and paediatric epidemiology.

  Katherine A Ahrens, Enrique F Schisterman
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):258-62.
• Article: Marginal structural models, doubly robust estimation, and bias analysis in perinatal and paediatric epidemiology.

  Onyebuchi A Arah, Madhuri Sudan, Jørn Olsen, Leeka Kheifets
  Paediatric and Perinatal Epidemiology 05/2013; 27(3):263-5.
• Article: Modelling Time to Death or Discharge in Neonatal Care: An Application of Competing Risks

  Sally R Hinchliffe, Sarah E Seaton, Paul C Lambert, Elizabeth S Draper, David J Field, Bradley N Manktelow
  Paediatric and Perinatal Epidemiology 04/2013;
• Article: A test of agreement of customised birthweight models.

  Kristen S Gibbons, Allan M Z Chang, Vicki J Flenady, Kassam Mahomed, Peter H Gray, Glenn J Gardener, Dominique Rossouw
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  ABSTRACT: The objective of this study was to determine whether the physiological effects on birthweight as described by customised birthweight models (CBMs) from various populations and locations are consistent when applied to a single sample. The predicted birthweight was calculated for 52 826 White-European singleton term births between 1997 and 2008 from a large Australian hospital using the same set of variables from 12 published CBMs. The accuracy of prediction was tested against both the actual birthweight and a reference model. Intraclass correlation coefficients (ICCs) along with 95% confidence intervals of the measurements, paired differences (predicted-actual birthweight) and absolute values of the paired differences are reported. The average difference in predicted and actual birthweight was <200 g for all CBMs, with ICCs for all but one model indicating fair agreement (between 0.3 and 0.5). When compared with the reference model, eight of the 11 models had a difference in predicted birthweight of <220 g, and the ICCs indicated that the majority of models had strong agreement. All published CBMs demonstrated ability to predict birthweight with reasonable accuracy. The effects of maternal and fetal characteristics on birthweight appear to be consistent across birthweight models. This finding is a further step in validating the CBM, and provides greater evidence for the creation of a global model.
  Paediatric and Perinatal Epidemiology 03/2013; 27(2):131-7.
• Article: Differences in Birthweight Curves Between Newborns of Immigrant Mothers vs. Infants Born in Their Corresponding Native Countries: Systematic Overview.

  Talia Boshari, Marcelo L Urquia, Michael Sgro, Leanne R De Souza, Joel G Ray
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  ABSTRACT: Newborn weight may vary between ethnic groups, but it is not known if birthweight differences exist between term babies born to immigrant mothers compared with those born in their corresponding native countries. We completed a systematic review of all birthweight curves published between 1980 and 2012, based on at least 100 singleton deliveries. We compared the 10th, 50th and 90th percentile birthweight values at 40 weeks gestation for male and female infants born in their native country vs. those infants born to mothers who had emigrated from their native country to Ontario, Canada. For the 50th percentile values, we also calculated a standardised pooled weighted difference and 95% confidence interval [CI] for both sexes. We also assessed whether birthweight differed over time, or if the differences varied by the Human Development Index (HDI) value for the native country. A total of 31 studies from 21 different countries met the inclusion criteria, comprising 13 317 578 males and 12 859 119 females born at 40 weeks gestation. There was a small non-significant rise in reported birthweight percentile values between 1983 and 2006. Nearly all infants born to women in their native country had lower birthweights than those born to mothers who had emigrated from the same country to Canada at the 10th, 50th and 90th percentiles. Overall, the 50th percentile weights differed by 115 g [95% CI 74, 156] for males and 122 g [95% CI 95, 150] for females. As HDI or median birthweight increased, birthweight differences were less pronounced, but not significantly so. Term birthweight percentiles are typically higher among term infants born to mother who immigrate to Canada than those of infants born in their respective native country.
  Paediatric and Perinatal Epidemiology 03/2013; 27(2):118-30.
• Article: Influence of Maternal and Paternal Birthweight on Offspring Birthweight - a Population-based Intergenerational Study.

  Kristina Mattsson, Lars Rylander
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  ABSTRACT: The correlation between infant birthweight and parental birthweight has received substantial interest. However, fewer studies including the birthweight of the father have had access to large sets of population-based data. The objective of this study is to examine the influence of maternal and paternal birthweight on the birthweight of the offspring in the context of other birthweight determinants, with a special focus on the contribution of paternal birthweight. The data used were retrieved from the Swedish Population Register, Medical Birth Register and Multi-Generation Register. Full-term, singleton births were included and linked through personal ID numbers given to every resident at birth, forming 137 538 mother-father-child units with valid birthweights. The analyses were made through linear regression models. The positive association for both maternal and paternal birthweight remained after introducing other determinants in the model, yielding a difference in offspring birthweight by 164 g [95% confidence interval 159, 170] and 149 g [95% confidence interval 145, 154] for every 1000 g rise in birthweight of the mother and father respectively. Maternal birthweight explained 6% of the variance in birthweight, whereas paternal birthweight explained 3%. There was no difference when analyses were stratified according to gender. These results suggest that maternal and paternal birthweight remain relevant for infant birthweight, even after consideration of other determinants of birthweight.
  Paediatric and Perinatal Epidemiology 03/2013; 27(2):138-44.
• Article: Risk factors for acute respiratory morbidity in moderately preterm infants.

  Maria Altman, Mireille Vanpée, Sven Cnattingius, Mikael Norman
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  ABSTRACT: Infants born preterm account for a substantial part of neonatal morbidity, with acute respiratory disorders being a dominating clinical problem. Whereas focus in recent studies has been on extremely and very preterm infants, less is known about contemporary rates and risk factors for acute respiratory morbidity in moderately and late preterm infants. The objective of this population-based Swedish study was to establish rates for different acute respiratory diseases in moderately preterm infants, and to identify maternal, obstetric and neonatal risk factors for the two most common diagnoses, transient tachypnoea of the newborn (TTN) and respiratory distress syndrome (RDS). The study included 4679 moderately preterm [gestational age (GA): 30 to 34 weeks], 15 036 late preterm infants (GA 35 to 36 weeks) and 451 479 term infants (GA: 37 to 41 weeks). All infants were born in 2004-2008. In moderately preterm infants, risk factors for TTN in multivariable analyses were multiparity, caesarean section before and after onset of labour, male sex, Apgar score 4-6 at 5 min and lower GA. Risk factors for RDS were multiparity, caesarean section before and after onset of labour, male sex, Apgar score <7 at 5 min and lower GA. Preterm rupture of membranes, antenatal corticosteroid treatment and being small for gestational age reduced the risk of RDS. We conclude that acute respiratory morbidity in moderately preterm infants is common and predicted by multiparity, caesarean section, low Apgar score and male sex.
  Paediatric and Perinatal Epidemiology 03/2013; 27(2):172-81.
• Article: Association between transient hypothyroxinaemia of prematurity and adult autism spectrum disorder in a low-birthweight cohort: an exploratory study.

  Steven J Korzeniewski, Jennifer A Pinto-Martin, Agnes H Whitaker, Judith F Feldman, John M Lorenz, Susan E Levy, Tammy Z Movsas, Athina Pappas, Nigel Paneth
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  ABSTRACT: Transient hypothyroxinaemia of prematurity (THOP) is associated with increased risk of cerebral palsy and lower IQ in low-birthweight infants. This study explores whether THOP is also associated with increased risk of autism spectrum disorders (ASD). This secondary analysis uses data from a birth cohort of newborns weighing 500 -2000 g (n = 1105) who were followed to age 21 years, when they were assessed for ASD in the second of a two-stage process. Of the 187 assessed at age 21, 14 had ASD. Neonatal thyroxine results were available for 12/14 and 165/173 participants diagnosed with and without ASD, respectively. THOP was defined as thyroxine z-score <-2.6. Unadjusted relative risks (RR) and confidence intervals (CI) were calculated. The mean neonatal thyroxine z-score in young adults diagnosed with ASD was 0.5 SD lower [95% CI -0.16, 1.06] than in those without ASD. Participants with THOP were at 2.5-fold greater risk of ASD (RR 2.5 [95% CI 0.7, 8.4]). While neither of these differences was statistically significant, in a secondary subgroup analysis of those whose mothers did not have hypertension during pregnancy, THOP significantly increased the RR for ASD (5.0 [95% CI 1.2, 20.5]). While the primary relation between THOP and ASD found here is not statistically significant, the magnitude of association and significant relationship observed in the subgroup whose mothers did not have hypertension during pregnancy suggest that it is worthy of further investigation.
  Paediatric and Perinatal Epidemiology 03/2013; 27(2):182-7.