Dataset Information

Risk factors for preterm birth in an international prospective cohort of nulliparous women.

ABSTRACT:

Objectives

To identify risk factors for spontaneous preterm birth (birth <37 weeks gestation) with intact membranes (SPTB-IM) and SPTB after prelabour rupture of the membranes (SPTB-PPROM) for nulliparous pregnant women.

Design

Prospective international multicentre cohort.

Participants

3234 healthy nulliparous women with a singleton pregnancy, follow up was complete in 3184 of participants (98.5%).

Results

Of the 3184 women, 156 (4.9%) had their pregnancy complicated by SPTB; 96 (3.0%) and 60 (1.9%) in the SPTB-IM and SPTB-PPROM categories, respectively. Independent risk factors for SPTB-IM were shorter cervical length, abnormal uterine Doppler flow, use of marijuana pre-pregnancy, lack of overall feeling of well being, being of Caucasian ethnicity, having a mother with diabetes and/or a history of preeclampsia, and a family history of low birth weight babies. Independent risk factors for SPTB-PPROM were shorter cervical length, short stature, participant's not being the first born in the family, longer time to conceive, not waking up at night, hormonal fertility treatment (excluding clomiphene), mild hypertension, family history of recurrent gestational diabetes, and maternal family history of any miscarriage (risk reduction). Low BMI (<20) nearly doubled the risk for SPTB-PPROM (odds ratio 2.64; 95% CI 1.07-6.51). The area under the receiver operating characteristics curve (AUC), after internal validation, was 0.69 for SPTB-IM and 0.79 for SPTB-PPROM.

Conclusion

The ability to predict PTB in healthy nulliparous women using clinical characteristics is modest. The dissimilarity of risk factors for SPTB-IM compared with SPTB-PPROM indicates different pathophysiological pathways underlie these distinct phenotypes.

Trial registration

ACTR.org.au ACTRN12607000551493.

SUBMITTER: Dekker GA

PROVIDER: S-EPMC3398037 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Risk factors for preterm birth in an international prospective cohort of nulliparous women.

Dekker Gustaaf Albert GA Lee Shalem Y SY North Robyn A RA McCowan Lesley M LM Simpson Nigel A B NA Roberts Claire T CT

PloS one 20120716 7

<h4>Objectives</h4>To identify risk factors for spontaneous preterm birth (birth <37 weeks gestation) with intact membranes (SPTB-IM) and SPTB after prelabour rupture of the membranes (SPTB-PPROM) for nulliparous pregnant women.<h4>Design</h4>Prospective international multicentre cohort.<h4>Participants</h4>3234 healthy nulliparous women with a singleton pregnancy, follow up was complete in 3184 of participants (98.5%).<h4>Results</h4>Of the 3184 women, 156 (4.9%) had their pregnancy complicated ...[more]

PMID: 22815699

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Project description:ObjectivesTo develop a predictive model for pre-eclampsia based on clinical risk factors for nulliparous women and to identify a subgroup at increased risk, in whom specialist referral might be indicated.DesignProspective multicentre cohort.SettingFive centres in Auckland, New Zealand; Adelaide, Australia; Manchester and London, United Kingdom; and Cork, Republic of Ireland.Participants3572 "healthy" nulliparous women with a singleton pregnancy from a large international study; data on pregnancy outcome were available for 3529 (99%).Main outcome measurePre-eclampsia defined as ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg, or both, on at least two occasions four hours apart after 20 weeks' gestation but before the onset of labour, or postpartum, with either proteinuria or any multisystem complication. Preterm pre-eclampsia was defined as women with pre-eclampsia delivered before 37(+0) weeks' gestation. In the stepwise logistic regression the comparison group was women without pre-eclampsia.ResultsOf the 3529 women, 186 (5.3%) developed pre-eclampsia, including 47 (1.3%) with preterm pre-eclampsia. Clinical risk factors at 14-16 weeks' gestation were age, mean arterial blood pressure, body mass index (BMI), family history of pre-eclampsia, family history of coronary heart disease, maternal birth weight, and vaginal bleeding for at least five days. Factors associated with reduced risk were a previous single miscarriage with the same partner, taking at least 12 months to conceive, high intake of fruit, cigarette smoking, and alcohol use in the first trimester. The area under the receiver operating characteristics curve (AUC), under internal validation, was 0.71. Addition of uterine artery Doppler indices did not improve performance (internal validation AUC 0.71). A framework for specialist referral was developed based on a probability of pre-eclampsia generated by the model of at least 15% or an abnormal uterine artery Doppler waveform in a subset of women with single risk factors. Nine per cent of nulliparous women would be referred for a specialist opinion, of whom 21% would develop pre-eclampsia. The relative risk for developing pre-eclampsia and preterm pre-eclampsia in women referred to a specialist compared with standard care was 5.5 and 12.2, respectively.ConclusionsThe ability to predict pre-eclampsia in healthy nulliparous women using clinical phenotype is modest and requires external validation in other populations. If validated, it could provide a personalised clinical risk profile for nulliparous women to which biomarkers could be added. Trial registration ACTRN12607000551493.

Project description:BackgroundAlthough uterine contractions have a diurnal periodicity and increase in frequency during hours of darkness, data on the relationship between sleep duration and sleep timing patterns and preterm birth are limited.ObjectiveWe sought to examine the relationship of self-reported sleep duration and timing in pregnancy with preterm birth.Study designIn the prospective Nulliparous Pregnancy Outcome Study: Monitoring Mothers-to-be cohort, women completed a survey of sleep patterns at 6-13 weeks gestation (visit 1) and again at 22-29 weeks gestation (visit 3). Additionally, at 16-21 weeks gestation (visit 2), a subgroup completed a weeklong actigraphy recording of their sleep. Weekly averages of self-reported sleep duration and sleep midpoint were calculated. A priori, sleep duration of <7 hours was defined as "short," and sleep midpoint after 5 am was defined as "late." The relationships among these sleep characteristics and all preterm birth and spontaneous preterm birth at <37 weeks gestation were examined in univariate analyses. Multivariable logistic regressions that controlled for age and body mass index alone (model 1) and with additional covariates (race, smoking, insurance, and employment schedule) following a backward elimination process (model 2) were performed.ResultsOf the 10,038 women who were enrolled, sleep survey data were available on 7524 women at visit 1 and 7668 women at visit 3. The rate of short sleep duration was 17.1% at visit 1 and 20.7% at visit 3. The proportion with a late sleep midpoint was 11.6% at visit 1 and 12.2% at visit 3. There was no significant relationship between self-reported short sleep and preterm birth across all visits. However, self-reported late sleep midpoint (>5 am) was associated with preterm birth . Women with a late sleep midpoint (>5 am) in early pregnancy had a preterm birth rate of 9.5%, compared with 6.9% for women with sleep midpoint ≤5 am (P=.005). Similarly, women with a late sleep midpoint had a higher rate of spontaneous preterm birth (6.2% vs 4.4%; P=.019). Comparable results were observed for women with a late sleep midpoint at visit 3 (all preterm birth 8.9% vs 6.6%; P=.009; spontaneous preterm birth 5.9% vs 4.3%; P=.023). All adjusted analyses on self-reported sleep midpoint (models 1 and 2) maintained statistical significance (P<.05), except for visit 1, model 2 for spontaneous preterm birth (P=.07). The visit 2 objective data from the smaller subgroup (n=782) demonstrated similar trends in preterm birth rates by sleep midpoint status.ConclusionSelf-reported late sleep midpoint in both early and late pregnancy, but not short sleep duration, is associated with an increased rate of preterm birth.

Project description:ObjectiveTo predict preterm birth in nulliparous women using logistic regression and machine learning.DesignPopulation-based retrospective cohort.ParticipantsNulliparous women (N = 112,963) with a singleton gestation who gave birth between 20-42 weeks gestation in Ontario hospitals from April 1, 2012 to March 31, 2014.MethodsWe used data during the first and second trimesters to build logistic regression and machine learning models in a "training" sample to predict overall and spontaneous preterm birth. We assessed model performance using various measures of accuracy including sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) in an independent "validation" sample.ResultsDuring the first trimester, logistic regression identified 13 variables associated with preterm birth, of which the strongest predictors were diabetes (Type I: adjusted odds ratio (AOR): 4.21; 95% confidence interval (CI): 3.23-5.42; Type II: AOR: 2.68; 95% CI: 2.05-3.46) and abnormal pregnancy-associated plasma protein A concentration (AOR: 2.04; 95% CI: 1.80-2.30). During the first trimester, the maximum AUC was 60% (95% CI: 58-62%) with artificial neural networks in the validation sample. During the second trimester, 17 variables were significantly associated with preterm birth, among which complications during pregnancy had the highest AOR (13.03; 95% CI: 12.21-13.90). During the second trimester, the AUC increased to 65% (95% CI: 63-66%) with artificial neural networks in the validation sample. Including complications during the pregnancy yielded an AUC of 80% (95% CI: 79-81%) with artificial neural networks. All models yielded 94-97% negative predictive values for spontaneous PTB during the first and second trimesters.ConclusionAlthough artificial neural networks provided slightly higher AUC than logistic regression, prediction of preterm birth in the first trimester remained elusive. However, including data from the second trimester improved prediction to a moderate level by both logistic regression and machine learning approaches.

Project description:ObjectivesTo assess the psychological well-being of pregnant women at increased risk of spontaneous preterm birth, and the impact of care from a preterm birth clinic.DesignSingle-centre longitudinal cohort study over 1 year, 2018-2019.SettingTertiary maternity hospital in Auckland, New Zealand.ParticipantsPregnant women at increased risk of spontaneous preterm birth receiving care in a preterm birth clinic.InterventionParticipants completed three sets of questionnaires (State-Trait Anxiety Inventory, Edinburgh Postnatal Depression Scale, and 36-Item Short Form Survey)-prior to their first, after their second, and after their last clinic appointments. Study-specific questionnaires explored pregnancy-related anxiety and perceptions of care.Primary and secondary outcome measuresThe primary outcome was the mean State-Anxiety score. Secondary outcomes included depression and quality of life measures.Results73/97 (75.3%) eligible women participated; 41.1% had a previous preterm birth, 31.5% a second trimester loss and 28.8% cervical surgery; 20.6% had a prior mental health condition. 63/73 (86.3%) women completed all questionnaires. The adjusted mean state-anxiety score was 39.0 at baseline, which decreased to 36.5 after the second visit (difference -2.5, 95% CI -5.5 to 0.5, p=0.1) and to 32.6 after the last visit (difference -3.9 from second visit, 95% CI -6.4 to -1.5, p=0.002). Rates of anxiety (state-anxiety score >40) and depression (Edinburgh Postnatal Depression Scale score >12) were 38.4%, 34.8%, 19.0% and 13.7%, 8.7%, 9.5% respectively, at the same time periods. Perceptions of care were favourable; 88.9% stated the preterm birth clinic made them significantly or somewhat less anxious and 87.3% wanted to be seen again in a future pregnancy.ConclusionsWomen at increased risk of spontaneous preterm birth have high levels of anxiety. Psychological well-being improved during the second trimester; women perceived that preterm birth clinic care reduced pregnancy-related anxiety. These findings support the ongoing use and development of preterm birth clinics.

Project description:Preterm birth is the major contributor for neonatal and under-five years mortality rates and also accounts for a short- and long-term adverse consequences up to adulthood. Perinatal outcomes may vary according to lots of factors as preterm subtype, late prematurity, which account for the vast majority of cases, country and population characteristics. An under-recognition of the perinatal outcomes and its associated factors might have underpowered strategies to provide adequate care and prevent its occurrence. We aim to estimate the frequency of maternal and perinatal outcomes in women with different categories of preterm and term births, factors associated with poorer perinatal outcomes and related management interventions. A multicentre prospective cohort in five maternities in Brazil between 2015 and 2018. Nulliparous low-risk women with singletons were included. Comprehensive data were collected during three antenatal visits (at 19-21weeks, 27-29 weeks and 37-39 weeks). Maternal and perinatal outcomes were also collected according to maternal and neonatal medical records. Women who had spontaneous (sPTB) and provider-initiated (pi-PTB) preterm birth were compared to those who had term birth. Also, late preterm birth (after 34 weeks), and early term (37-38 weeks) were compared to full term birth (39-40 weeks). Bivariate analysis estimated risk ratios for maternal and adverse outcomes. Finally, a multivariate analysis was conducted to address factors independently associated with any adverse perinatal outcome (APO). In total, 1,165 women had outcome data available, from which 6.7% had sPTB, 4.0% had pi-PTB and 89.3% had a term birth. sPTB and pi-PTb were associated with poorer perinatal outcomes, as well as late sPTB, late pi-PTB and early term neonates. pi-PTB (RRadj 8.12, 95% CI [2.54-25.93], p-value 0.007), maternal weight gain between 20 and 27 weeks <p10 (RRadj 2.04, 95% CI [1.23-3.38], p-value 0.018) and participants from the Northeast centres (RRadj 2.35, 95% CI [1.11-4.95], p-value 0.034) were independently associated with APO. According to our findings, Brazil would benefit from strategies to more accurately identify women at higher risk for PTB, to promote evidenced-based decision in preterm and early term provider-initiated deliveries, and to prevent perinatal adverse outcomes.

Dataset Information

Risk factors for preterm birth in an international prospective cohort of nulliparous women.

Objectives

Design

Participants

Results

Conclusion

Trial registration

Publications

Risk factors for preterm birth in an international prospective cohort of nulliparous women.

Similar Datasets

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