-
[show abstract]
[hide abstract]
ABSTRACT: To describe the use of episiotomy among Vietnamese-born women in Australia, including risk factors for, and pregnancy outcomes associated with, episiotomy.
This population-based, retrospective cohort study included data on 598 305 singleton, term (i.e. ≥ 37 weeks' gestation) and vertex-presenting vaginal births between 2001 and 2010. Data were obtained from linked, validated, population-level birth and hospitalization data sets. Contingency tables and multivariate analysis were used to compare risk factors and pregnancy outcomes in women who did or did not have an episiotomy.
The episiotomy rate in 12 208 Vietnamese-born women was 29.9%, compared with 15.1% in Australian-born women. Among Vietnamese-born women, those who had an episiotomy were significantly more likely than those who did not to be primiparous, give birth in a private hospital, have induced labour or undergo instrumental delivery. In these women, having an episiotomy was associated with postpartum haemorrhage (adjusted odds ratio, aOR: 1.26; 95% confidence interval, CI: 1.08-1.46) and postnatal hospitalization for more than 4 days (aOR: 1.14; 95% CI: 1.00-1.29). Among multiparous women only, episiotomy was positively associated with a third- or fourth-degree perineal tear (aOR: 2.00; 95% CI: 1.31-3.06); in contrast, among primiparous women the association was negative (aOR: 0.47; 95% CI: 0.37-0.60).
Episiotomy was performed in far fewer Vietnamese-born women giving birth in Australia than in Viet Nam, where more than 85% undergo the procedure, and was not associated with adverse outcomes. A lower episiotomy rate should be achievable in Viet Nam.
Bulletin of the World Health Organisation 05/2013; 91(5):350-6. · 4.64 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To identify the greatest potential for reducing overall caesarean delivery rates, we used longitudinally linked data for women with consecutive births 2001-2009 to examine the likely impact of hypothetical risk-based scenarios. Among women with a first birth, singleton, vertex-presenting fetus at term, increasing the vaginal birth rate following induction of labour by 20% potentially has greatest impact, with a 12.1% relative decrease in the overall caesarean rate. The potential relative decrease in other scenarios ranged from 0.8 to 5.9%.
Australian and New Zealand Journal of Obstetrics and Gynaecology 03/2013; · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Changes in clinical practice and in the characteristics of childbearing women have the potential to influence the rate of obstetric anal sphincter injuries (OASIS). To date, little investigation has been undertaken to assess the effect of risk factor trends for the Australian population on OASIS rates.
To ascertain the OASIS rates amongst singleton vaginal births ≥37 weeks gestation in NSW, 2001 - 2009; to determine risk factor effect sizes and trends; and to compare predicted with observed OASIS rates.
Using two linked population-based data sets, risk factors for OASIS were determined by logistic regression. Contingency tables and predictive modelling were used to determine trends and predicted rates of OASIS, respectively.
The OASIS rate increased from 2.2% in 2001 to 2.9% in 2009. Highest risks were for forceps deliveries without episiotomy (primiparas aOR 6.10, multiparas aOR 6.15), followed by multiparas with no previous vaginal birth (aOR 5.61). High birthweight, vacuum delivery and Asian country of birth posed risks for all women. The greatest risk factor trends were increases in Asian country of birth and vacuum delivery, while the greatest trend amongst protective factors was an increase in maternal age ≥35 years for primiparas. Predicted OASIS rates were lower than observed rates.
In an environment of changing demographic and clinical risk factors, the OASIS rate has increased. This increase is only minimally explained by the identified risk factors and may be related to other unmeasured risk factors or a possible increase in clinical ascertainment and/or documentation of OASIS.
Australian and New Zealand Journal of Obstetrics and Gynaecology 02/2013; 53(1):9-16. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Objective: To investigate changes in maternal length of postnatal stay by mode of birth and hospital type, and examine concurrent maternal readmission rates and reasons for readmission. Methods: Linked birth and hospital separation data were used to investigated mothers' birth admissions (n=597,475) and readmissions (n=19,094) in the six weeks post-birth in New South Wales, 2001-2007. Outcomes were postnatal length of stay (mean days) and rate of readmission per 100 deliveries. Poisson regression was used to investigate annual readmission rates and Wilcoxon-Mann-Whitney test was used to compare length of readmission stays. Results: The overall mean postnatal length of stay declined from 3.7 days in 2001 to 3.4 days in 2007. Private hospitals had longer stays after Caesarean and vaginal deliveries, but mean length of stay fell for both private and public hospitals, and both modes of birth. The maternal readmission rate fell from 3.4% in 2001 to 3.0% in 2007. Leading primary diagnoses at readmission following vaginal birth were postpartum haemorrhage and breast/ lactation complications and following Caesarean section were wound complications and breast/ lactation complications. Conclusions: Despite the decrease in mean length of stay for birth admissions, there was no increase, and in fact a decrease, in the rate of postnatal readmissions. Implications: Current practices in hospital length of stay and care for women giving birth do not appear to be having serious adverse health effects as measured by readmissions.
Australian and New Zealand Journal of Public Health 10/2012; 36(5):430-4. · 1.20 Impact Factor
-
Australian health review: a publication of the Australian Hospital Association 09/2012; · 0.55 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to describe trends and outcomes of planned births.
Data from linked birth and hospital records for 779,521 singleton births at ≥33 weeks' gestation from 2001-2009 were used to determine trends in planned births (prelabor cesarean section and labor inductions). Adverse outcomes were composite indicators of maternal and neonatal morbidity/death.
From 2001-2009, there were increases in labor inductions and prelabor cesarean deliveries at <40 weeks' gestation, but no decrease in the stillbirth rate (trend P = .34). By 2009, 14.9% of live births at ≥33 weeks' gestation were prelabor cesarean deliveries before the due date; 11.4% were inductions. As planned births increased, maternal risks shifted, which included a decline in inductions with maternal hypertension from 31.9-23.9%. Earlier birth was contemporaneous with increases (trend P < .001) in neonatal and maternal morbidity rates from 3.0-3.2% and 1.1-1.5%, respectively.
Planned birth before the due date is increasing without a contemporaneous reduction of stillbirths.
American journal of obstetrics and gynecology 09/2012; 207(3):186.e1-8. · 3.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We determined recent trends and recurrence rates of placenta praevia in 790,366 deliveries in NSW. From 2001 to 2009, the rate of placenta praevia increased by 26%, from 0. 69% to 0. 87% (trend P < 0.001). The placenta praevia recurrence rate in a second birth was 4.8%. Two-thirds of the increase in placenta praevia was accounted for by trends in known risk factors, and the unexplained portion may reflect changes in unidentified risk factors or in the threshold for placenta praevia diagnosis.
Australian and New Zealand Journal of Obstetrics and Gynaecology 08/2012; 52(5):483-6. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Context: High serum levels of TSH have been associated with adverse pregnancy outcomes by some studies, and not by others. Objective: The aim of the study was to assess the association between high levels of TSH in the first trimester of pregnancy and adverse pregnancy outcomes; and to examine the predictive accuracy as a screening test. Setting and Participants: Serum levels of TSH were measured in a cohort of 2801 women with a singleton pregnancy attending first trimester Down syndrome screening. Information on maternal and infant outcomes was obtained through record linkage to population-based birth and hospital data. Association between high TSH (>95th and >97.5th centiles) multiple of the median levels, and risk of adverse pregnancy outcomes was evaluated using multivariable logistic regression, and the predictive accuracy of models was assessed. Main Outcomes: Rates of infants being small for gestational age (SGA), preterm birth, preeclampsia, miscarriage, and stillbirth were investigated. Results: High TSH multiple of the median levels were associated with SGA (<10th centile) [adjusted odds ratio (aOR), 1.71; 95% confidence interval (CI), 0.99-2.94]; preterm birth at less than 37 wk gestation (aOR, 2.59; 95% CI, 1.21-5.53); miscarriage (aOR, 3.66; 95% CI, 1.59-8.44); and a composite measure of any study outcome (aOR, 2.10; 95% CI, 1.23-3.59). The area under the receiver operator characteristic curves were 0.69 (95% CI, 0.65-0.73) for SGA; 0.56 (95% CI, 0.51-0.61) for preterm birth; 0.70 (95% CI, 0.61-0.79) for miscarriage; and 0.63 (95% CI, 0.60-0.65) for any adverse pregnancy outcome. Conclusions: High TSH serum levels during the first trimester of pregnancy were associated with adverse pregnancy outcomes; however, the predictive accuracy was poor. Screening for high TSH levels in the first trimester would be of no benefit to identify women at risk.
The Journal of clinical endocrinology and metabolism 06/2012; 97(9):3115-22. · 6.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To assess the frequency and outcomes of preterm hospital admissions during pregnancy, with a focus on transfers to higher levels of care.
Population-based cohort study using linked population data.
Women who were admitted to hospital in weeks 20-36 of pregnancy (preterm) and gave birth to a liveborn singleton infant in New South Wales during 2001-2008.
Numbers of preterm admissions of pregnant women who were discharged without giving birth, were transferred to higher care, or who gave birth.
110,439 pregnancies (16.0%) involved at least one preterm admission. After their initial preterm admission, 71.9% of women were discharged, 6.3% were transferred and 21.8% gave birth. Median gestational age at admission was 33 weeks and median time to discharge, transfer or giving birth was 1 day. Most women who were transferred or who gave birth had been admitted for preterm rupture of membranes or preterm labour. Of the women who were admitted or were transferred with suspected preterm labour, only 29% and 38%, respectively, gave birth. Compared with other admitted women, women having a first birth, public patients and those living in areas of low socioeconomic status were more likely to be transferred or to give birth. As gestational age increased, the proportion of women transferred decreased and the proportion giving birth increased. Infants born after maternal transfer had lower gestational age and more adverse outcomes than those born without maternal transfer.
Preterm hospital admission affects one in six women with singleton pregnancies. Methods that could improve assessment of labour status have a large potential to reduce the burden on maternity services. The increased morbidity for infants born after maternal transfer suggests women with high-risk pregnancies are being appropriately identified.
The Medical journal of Australia 03/2012; 196(4):261-5. · 2.81 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the trends in oxytocin use at a population level within New South Wales and to assess the maternal and neonatal morbidities associated with the use of oxytocin.
Trends in oxytocin use were assessed for women in NSW who were nulliparas at term with a singleton, cephalic fetus between 1998 and 2008. Maternal and neonatal morbidities were assessed in 2007-2008 using linked hospital and birth data with regression analysis. Oxytocin was also assessed by indication for use being either induction or augmentation of labour.
The overall use of oxytocin increased from 10,291 (36.5%) of births in 1998 to 14,440 (45.4%) of births in 2008 (P < 0.0001) with the increase entirely because of the increased use for induction of labour. The use of oxytocin was associated with an increase in regional analgesia (65 to 22%), instrumental delivery (21 to 18%) and caesarean section (29 to 14%) as compared to women who did not receive oxytocin in labour. Oxytocin was also associated with an increase in severe maternal adjusted odds ratios ((aOR) 1.48, 95% CI 1.30-1.68) and neonatal morbidity (aOR 1.29, 95% CI 1.17-1.41). This increase in morbidity was maintained when both augmentation and induction were assessed separately.
Oxytocin has an important role in the management of labour. However, its use should be carefully monitored with standardised treatment regimes to minimise maternal and neonatal morbidity.
Australian and New Zealand Journal of Obstetrics and Gynaecology 03/2012; 52(2):173-8. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine whether the obstetric pathways leading to caesarean section changed from one decade to another. We also aimed to explore how much of the increase in caesarean rate could be attributed to maternal and pregnancy factors including a shift towards delivery in private hospitals.
Population-based record linkage cohort study.
New South Wales, Australia.
For annual rates, all women giving birth in NSW during 1994 to 2009 were included. To examine changes in obstetric pathways two cohorts were compared: all women with a first-birth during either 1994-1997 (82 988 women) or 2001-2004 (85 859 women) and who had a second (sequential) birth within 5 years of their first-birth.
Caesarean section rates, by parity and onset of labour.
For first-births, prelabour and intrapartum caesarean rates increased from 1994 to 2009, with intrapartum rates rising from 6.5% to 11.7%. This fed into repeat caesarean rates; from 2003, over 18% of all multiparous births were prelabour repeat caesareans. In the 1994-1997 cohort, 17.7% of women had a caesarean delivery for their first-birth. For their second birth, the vaginal birth after caesarean (VBAC) rate was 28%. In the 2001-2004 cohort, 26.1% of women had a caesarean delivery for their first-birth and the VBAC rate was 16%. Among women with a first-birth, maternal and pregnancy factors and increasing deliveries in private hospitals, only explained 24% of the rise in caesarean rates from 1994 to 2009.
Rising first-birth caesarean rates drove the overall increase. Maternal factors and changes in public/private care could explain only a quarter of the increase. Changes in the perceived risks of vaginal birth versus caesarean delivery may be influencing the pregnancy management decisions of clinicians and/or mothers.
BMJ open. 01/2012; 2(5).
-
[show abstract]
[hide abstract]
ABSTRACT: To determine induction trends and delivery, maternal and neonatal health outcomes by gestational age following induction at term for women having a first baby.
Linked birth and hospital data were used to examine the rates of adverse maternal and neonatal health outcomes for the period 2001-2007, among the 212,389 nullipara with singleton cephalic-presenting fetuses delivering between 37(0) and 41(6) weeks of gestation. Rates of caesarean delivery, neonatal transfers and overall severe neonatal and maternal adverse outcomes were determined by gestational age.
Between 1990 and 2008, nulliparous term inductions as a proportion of all births increased from 5518 (6.8%) to 11,166 (12.5%). More than 60% of these inductions are performed before 41 weeks. Among induced nullipara, 30.4% delivered by caesarean section. Adverse neonatal outcomes and transfer rates were lowest at 39-40 weeks (overall 2.1 and 0.5%, respectively), regardless of labour onset. Maternal morbidity increased at 40 weeks (from 1.1 to 1.3%) for women in spontaneous labour, was relatively stable in those undergoing induction of labour between 37 and 40 weeks (1.8%) and decreased with gestational age until 40 weeks in those undergoing a prelabour caesarean delivery (from 3.1 to 0.8%).
NSW has high rates of both induction and caesarean section following induction. This study highlights the changes to clinical practice that may help reduce the rate of caesarean births in nullipara.
Australian and New Zealand Journal of Obstetrics and Gynaecology 07/2011; 51(6):510-7. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Angiogenic factors are involved in formation of new blood vessels required for placental development and function; and critical for fetal growth and development. Soluble fms-like tyrosine kinase 1(sFlt-1) is an anti-angiogenic protein that inhibits formation of new blood vessels resulting in potential pregnancy complications. The objective of this study was to undertake a systematic review to assess levels of sFlt-1 in early pregnancy and association with adverse pregnancy outcomes. PubMed and Medline databases and reference lists were searched up to July 2010. Inclusion criteria were pregnant women, blood sample taken during first trimester and assessment/reporting of sFlt-1 concentrations and subsequent pregnancy complications. Twelve relevant studies were identified of 71 to 668 women. No pooling of results was undertaken due to variation in sFlt-1 concentrations (range, 166-6,349 pg/ml amongst controls), samples used (serum, plasma), different summary statistics (mean, median, odds ratio) and outcome definitions applied. Levels of sFlt-1 were generally higher among women who developed preeclampsia (11 studies) or gestational hypertension (two studies), but not significantly different to normotensive women in most studies. There was no consistent pattern in association between sFlt-1 concentrations and fetal growth restriction (4 studies); and levels were non-significantly higher for women with postpartum bleeding (1 study) and significantly lower for stillbirths (1 study).This review found no clear evidence of an association between sFlt-1 levels in first trimester and adverse pregnancy outcomes. However, findings were affected by methodological, biological and testing variations between studies; highlighting the need for consistent testing of new biomarkers and reporting of outcome measures.
Reproductive Biology and Endocrinology 06/2011; 9:77. · 2.05 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We undertook a systematic review to assess normative levels of vitamin D in early pregnancy and association with subsequent pregnancy outcomes.
Medline and Embase databases and reference lists were searched. Inclusion criteria were pregnant populations, blood sample taken during the first trimester, and serum hydroxyvitamin D levels assessed.
Eighteen studies reported vitamin D levels in first trimester (n = 11-3730), and 5 examined pregnancy outcomes. Mean vitamin D concentrations differed when stratified by ethnicity: white (mean [SD]: 29.4 [11.7] to 73.1 [27.1] nmol/L) and nonwhite (15.2 [12.1] to 43 [12] nmol/L). Most studies used general population cut points to define deficiency and found a large proportion of women deficient. Two articles examined risk of preeclampsia and reported differing findings, whereas 2 of 3 found low levels associated with increased risk of small-for-gestational age births.
There is no clear definition of vitamin D deficiency in pregnancy and insufficient evidence to suggest low vitamin D levels in early pregnancy are associated with adverse pregnancy outcomes.
American journal of obstetrics and gynecology 04/2011; 205(3):208.e1-7. · 3.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Successful pregnancy requires strict temporal regulation of maternal immune function to accommodate the growing fetus. Early implantation is facilitated by inflammatory processes that ensure adequate vascular remodeling and placental invasion. To prevent rejection of the fetus, this inflammation must be curtailed; reproductive immunologists are discovering that this process is orchestrated by the fetal unit and, in particular, the extravillous trophoblast. Soluble and particulate factors produced by the trophoblast regulate maternal immune cells within the decidua, as well as in the periphery. The aim of this review is to discuss the action of recently discovered immunomodulatory factors and mechanisms, and the potential effects of dysregulation of such mechanisms on the maternal immune response that may result in pregnancy loss or preeclampsia.
Reproduction 03/2011; 141(6):715-24. · 2.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although the connection between ascending infection and preterm birth is undisputed, research focused on finding effective treatments has been disappointing. However evidence that eradication of Candida in pregnancy may reduce the risk of preterm birth is emerging. We conducted a pilot study to assess the feasibility of conducting a large randomized controlled trial to determine whether treatment of asymptomatic candidiasis in early pregnancy reduces the incidence of preterm birth.
We used a prospective, randomized, open-label, blinded-endpoint (PROBE) study design. Pregnant women presenting at <20 weeks gestation with singleton pregnancies self-collected a vaginal swab. Those who were asymptomatic and culture positive for Candida were randomized to 6-days of clotrimazole vaginal pessaries (100mg) or usual care (screening result is not revealed, no treatment). The primary outcomes were the rate of asymptomatic vaginal candidiasis, participation and follow-up. The proposed primary trial outcome of spontaneous preterm birth <37 weeks gestation was also assessed.
Of 779 women approached, 500 (64%) participated in candidiasis screening, and 98 (19.6%) had asymptomatic vaginal candidiasis and were randomized to clotrimazole or usual care. Women were not inconvenienced by participation in the study, laboratory testing and medication dispensing were problem-free, and the follow-up rate was 99%. There was a tendency towards a reduction in spontaneous preterm birth among women with asymptomatic candidiasis who were treated with clotrimazole RR = 0.33, 95%CI 0.04-3.03.
A large, adequately powered, randomized trial of clotrimazole to prevent preterm birth in women with asymptomatic candidiasis is both feasible and warranted.
Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609001052224.
BMC Pregnancy and Childbirth 03/2011; 11:18. · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Prevention of preterm birth remains one of the most important challenges in maternity care. We propose a randomised trial with: a simple Candida testing protocol that can be easily incorporated into usual antenatal care; a simple, well accepted, treatment intervention; and assessment of outcomes from validated, routinely-collected, computerised databases.
Using a prospective, randomised, open-label, blinded-endpoint (PROBE) study design, we aim to evaluate whether treating women with asymptomatic vaginal candidiasis early in pregnancy is effective in preventing spontaneous preterm birth. Pregnant women presenting for antenatal care<20 weeks gestation with singleton pregnancies are eligible for inclusion. The intervention is a 6-day course of clotrimazole vaginal pessaries (100 mg) and the primary outcome is spontaneous preterm birth<37 weeks gestation.The study protocol draws on the usual antenatal care schedule, has been pilot-tested and the intervention involves only a minor modification of current practice. Women who agree to participate will self-collect a vaginal swab and those who are culture positive for Candida will be randomised (central, telephone) to open-label treatment or usual care (screening result is not revealed, no treatment, routine antenatal care). Outcomes will be obtained from population databases.A sample size of 3,208 women with Candida colonisation (1,604 per arm) is required to detect a 40% reduction in the spontaneous preterm birth rate among women with asymptomatic candidiasis from 5.0% in the control group to 3.0% in women treated with clotrimazole (significance 0.05, power 0.8). Analyses will be by intention to treat.
For our hypothesis, a placebo-controlled trial had major disadvantages: a placebo arm would not represent current clinical practice; knowledge of vaginal colonisation with Candida may change participants' behaviour; and a placebo with an alcohol preservative may have an independent affect on vaginal flora. These disadvantages can be overcome by the PROBE study design.This trial will provide definitive evidence on whether screening for and treating asymptomatic candidiasis in pregnancy significantly reduces the rate of spontaneous preterm birth. If it can be demonstrated that treating asymptomatic candidiasis reduces preterm births this will change current practice and would directly impact the management of every pregnant woman.
Australian New Zealand Clinical Trials Registry ACTRN12610000607077.
BMC Pregnancy and Childbirth 03/2011; 11:19. · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Th1 immune responses are suppressed in pregnancy, but the temporal regulation and the mechanism(s) underlying this immune alteration are unknown. We assessed the expression of Th1 cytokines IFNγ, IL-2 and TNFα in response to stimulation in isolated T-cells from pregnant women throughout gestation. Using flow cytometry we demonstrated an early and sustained reduction in IFNγ and IL-2 production in CD3+ T-cells, but TNFα levels are not reduced until the third trimester. We assessed the expression of NF-κB and T-bet, transcription factors that play a central role in Th1 immune responses, throughout pregnancy. In isolated T-cells levels of available p65 were suppressed early in pregnancy, but T-bet expression was suppressed only in the third trimester. In contrast to p65, T-bet expression was transcriptionally regulated, with diminished T-bet mRNA in third-trimester samples. Re-expression of p65 in T-cells from third-trimester pregnant women resulted in an induction of T-bet expression in response to PMA stimulation and a concomitant increase in the production of IL-2 and IFNγ. The suppressive effect of pregnancy was ameliorated as early as 72h post-partum when p65 levels returned to normal as did the level of inducible IFNγ and IL-2. TNFα levels in post-partum women were significantly increased relative to non-pregnant controls. The pregnancy-specific suppression of p65 and subsequent loss of cytokine production suggest that this transcription factor acts specifically to regulate the cytokine environment that is required for pregnancy success.
Journal of Reproductive Immunology 03/2011; 89(1):1-9. · 2.97 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Caesarean section (CS) rates around the world have been increasing and in Australia have reached 30% of all births. Robson's Ten-Group Classification System (10-group classification) provides a clinically relevant classification of CS rates that provides a useful basis for international comparisons and trend analyses. This study aimed to investigate trends in CS rates in New South Wales (NSW), including trends in the components of the 10-group classification.
We undertook a cross-sectional study using data from the Midwives Data Collection, a state-wide surveillance system that monitors patterns of pregnancy care, services and pregnancy outcomes in New South Wales, Australia. The study population included all women giving birth between 1st January 1998 and 31st December 2008. Descriptive statistics are presented including age-standardised CS rates, annual percentage change as well as regression analyses.
From 1998 to 2008 the CS rate in NSW increased from 19.1 to 29.5 per 100 births. There was a significant average annual increase in primary 4.3% (95%CI 3.0-5.7%) and repeat 4.8% (95% CI 3.9-5.7%) CS rates from 1998 to 2008. After adjusting for maternal and pregnancy factors, the increase in CS delivery over time was maintained. When examining CS rates classified according to the 10-group classification, the greatest contributors to the overall CS rate and the largest annual increases occurred among nulliparae at term having elective CS and multipara having elective repeat CS.
Given that the increased CS rate cannot be explained by known and collected maternal or pregnancy characteristics, the increase may be related to differences in clinical decision making or maternal request. Future efforts to reduce the overall CS rate should be focussed on reducing the primary CS rate.
BMC Pregnancy and Childbirth 01/2011; 11:8. · 2.83 Impact Factor
-
Christine L Roberts,
Jane B Ford,
Charles S Algert,
Sussie Antonsen,
James Chalmers,
Sven Cnattingius,
Manjusha Gokhale,
Milton Kotelchuck,
Kari K Melve,
Amanda Langridge,
Carole Morris, Jonathan M Morris,
Natasha Nassar,
Jane E Norman,
John Norrie,
Henrik Toft Sørensen,
Robin Walker,
Christopher J Weir
[show abstract]
[hide abstract]
ABSTRACT: The objective of this study was to compare international trends in pre-eclampsia rates and in overall pregnancy hypertension rates (including gestational hypertension, pre-eclampsia and eclampsia).
Population data (from birth and/or hospital records) on all women giving birth were available from Australia (two states), Canada (Alberta), Denmark, Norway, Scotland, Sweden and the USA (Massachusetts) for a minimum of 6 years from 1997 to 2007. All countries used the 10th revision of the International Classification of Diseases, except Massachusetts which used the 9th revision. There were no major changes to the diagnostic criteria or methods of data collection in any country during the study period. Population characteristics as well as rates of pregnancy hypertension and pre-eclampsia were compared.
Absolute rates varied across the populations as follows: pregnancy hypertension (3.6% to 9.1%), pre-eclampsia (1.4% to 4.0%) and early-onset pre-eclampsia (0.3% to 0.7%). Pregnancy hypertension and/or pre-eclampsia rates declined over time in most populations. This was unexpected given that factors associated with pregnancy hypertension such as pre-pregnancy obesity and maternal age are generally increasing. However, there was also a downward shift in gestational age with fewer pregnancies reaching 40 weeks.
The rate of pregnancy hypertension and pre-eclampsia decreased in northern Europe and Australia from 1997 to 2007, but increased in Massachusetts. The use of a different International Classification of Diseases coding version in Massachusetts may contribute to the difference in trend. Elective delivery prior to the due date is the most likely explanation for the decrease observed in Europe and Australia. Also, the use of interventions that reduce the risk of pregnancy hypertension and/or progression to pre-eclampsia (low-dose aspirin, calcium supplementation and early delivery for mild hypertension) may have contributed to the decline.
BMJ open. 01/2011; 1(1):e000101.
