METHODS: This was a prospective cohort study of 334 nulliparous women booking antenatal care at University College London Hospital between August 2008 and September 2009. Women underwent a transabdominal ultrasound examination of uterine arteries for measurement of TVFR at 12, 20 and 24 weeks' gestation. Pregnancy outcomes were recorded and linear regression was used to study the relationship between TVFR and gestational age at delivery and birth weight.

RESULTS: A total of 551 ultrasound scans were performed. There was a significant, positive correlation between TVFR at 11-13 weeks (TVFR1) and at 22-26 weeks (TVFR3) and birth weight. For every 100-mL/min increase in TVFR1 and TVFR3, there was an increase in birth weight of 45 g and 27 g, respectively. There was also a positive association between TVFR1 and gestational age at delivery, with a 1.4-day increase in gestational age for every 100-mL/min increase of TVFR1.

OBJECTIVE: The aim of this study was to evaluate regular (4-hourly prior to each oral misoprostol dose with amniotomy when feasible) compared with restricted (only if indicated) vaginal assessments during labor induction with oral misoprostol in term nulliparous women MATERIALS AND METHODS: We performed a randomized trial between November 2016 and September 2017 in a university hospital in Malaysia. Our oral misoprostol labor induction regimen comprised 50 μg of misoprostol administered 4 hourly for up to 3 doses in the first 24 hours. Participants assigned to regular assessment had vaginal examinations before each 4-hourly misoprostol dose with a view to amniotomy as soon as it was feasible. Participants in the restricted arm had vaginal examinations only if indicated. Primary outcomes were patient satisfaction with the birth process (using an 11-point visual numerical rating scale), induction to vaginal delivery interval, and vaginal delivery rate at 24 hours.

RESULTS: Data from 204 participants (101 regular, 103 restricted) were analyzed. The patient satisfaction score with the birth process was as follows (median [interquartile range]): 7 [6-9] vs 8 [6-10], P = .15. The interval of induction to vaginal delivery (mean ± standard deviation) was 24.3 ± 12.8 vs 31.1 ± 15.0 hours (P = .013). The vaginal delivery rate at 24 hours was 27.7% vs 20.4%; (relative risk [RR], 1.4; 95% confidence interval [CI], 0.8-2.3; P = .14) for the regular vs restricted arms, respectively. The cesarean delivery rate was 50% vs 43% (RR, 1.1; 95% CI, 0.9-1.5; P = .36). When assessed after delivery, participants' fidelity to their assigned vaginal examination schedule in a future labor induction was 45% vs 88% (RR, 0.5; 95% CI, 0.4-0.7; P < .001), and they would recommend their assigned schedule to a friend (47% vs 87%; RR, 0.6; 95% CI, 0.5-0.7; P < .001) in the regular compared with the restricted arms, respectively.

METHODS AND FINDINGS: We searched the major electronic databases Medline, Embase, and Google Scholar (January 1990-October 2018) without language restrictions. We included cohort studies on term pregnancies that provided estimates of stillbirths or neonatal deaths by gestation week. We estimated the additional weekly risk of stillbirth in term pregnancies that continued versus delivered at various gestational ages. We compared week-specific neonatal mortality rates by gestational age at delivery. We used mixed-effects logistic regression models with random intercepts, and computed risk ratios (RRs), odds ratios (ORs), and 95% confidence intervals (CIs). Thirteen studies (15 million pregnancies, 17,830 stillbirths) were included. All studies were from high-income countries. Four studies provided the risks of stillbirth in mothers of White and Black race, 2 in mothers of White and Asian race, 5 in mothers of White race only, and 2 in mothers of Black race only. The prospective risk of stillbirth increased with gestational age from 0.11 per 1,000 pregnancies at 37 weeks (95% CI 0.07 to 0.15) to 3.18 per 1,000 at 42 weeks (95% CI 1.84 to 4.35). Neonatal mortality increased when pregnancies continued beyond 41 weeks; the risk increased significantly for deliveries at 42 versus 41 weeks gestation (RR 1.87, 95% CI 1.07 to 2.86, p = 0.012). One additional stillbirth occurred for every 1,449 (95% CI 1,237 to 1,747) pregnancies that advanced from 40 to 41 weeks. Limitations include variations in the definition of low-risk pregnancy, the wide time span of the studies, the use of registry-based data, and potential confounders affecting the outcome.

CONCLUSIONS: Our findings suggest there is a significant additional risk of stillbirth, with no corresponding reduction in neonatal mortality, when term pregnancies continue to 41 weeks compared to delivery at 40 weeks.