Stillbirth or neonatal death before 45 post-menstrual weeks in relation to gestational duration in pregnancies at 39 weeks of gestation or beyond: the impact of parity and body mass index. A national cohort study

Put your weight behind it-Effect of body mass index on the active second stage of labour: A retrospective cohort study

OBJECTIVE

To explore the duration of the active phase of the second stage of labour in relation to maternal pre-pregnant body mass index (BMI).

DESIGN

Retrospective cohort study.

SETTING

Labour wards of three Norwegian university hospitals, 2012-2019.

POPULATION

Nulliparous and parous women without previous caesarean section with a live singleton fetus in cephalic presentation and spontaneous onset of labour, corresponding to the Ten Group Classification System (TGCS) group 1 and 3.

METHODS

Women were stratified to BMI groups according to WHO classification, and estimated median duration of the active phase of the second stage of labour was calculated using survival analyses. Caesarean sections and operative vaginal deliveries during the active phase were censored.

MAIN OUTCOME MEASURES

Estimated median duration of the active phase of second stage of labour.

RESULTS

In all, 47 942 women were included in the survival analyses. Increasing BMI was associated with shorter estimated median duration of the active second stage in both TGCS groups. In TGCS group 1, the estimated median durations (interquartile range) were 44 (26-75), 43 (25-71), 39 (22-70), 33 (18-63), 34 (19-54) and 29 (16-56) minutes in BMI groups 1-6, respectively. In TGCS group 3, the corresponding values were 11 (6-19), 10 (6-17), 10 (6-16), 9 (5-15), 8 (5-13) and 7 (4-11) minutes. Increasing BMI remained associated with shorter estimated median duration in analyses stratified by oxytocin augmentation and epidural analgesia.

CONCLUSION

Increasing BMI was associated with shorter estimated median duration of the active second stage of labour.

Relation between perinatal outcome and gestational duration in term primiparous pregnancies stratified by body mass index

INTRODUCTION

There is growing evidence that induction of labor at 41 completed weeks improves neonatal outcome, at least among primiparous women. This study was performed to investigate whether maternal body mass index (BMI) should be considered when deciding on timing of intervention in term pregnancies.

MATERIAL AND METHODS

The study design was a historical cohort study using data from the Swedish Medical Birth Register, singletons in cephalic presentation with births 39+0 to 41+6 weeks, with available information on maternal BMI 2005-2017 (n = 352 567). Modified Poisson regression analyses were used to investigate the association between gestational duration and stillbirth or death before 45 postmenstrual weeks (primary outcome) and Apgar score <7 at 5 minutes (secondary outcome) by BMI, respectively. Adjustments were made for maternal age, smoking, country of birth and educational level.

RESULTS

The adjusted relative risk (ARR) of stillbirth or death before 45 weeks among infants born at 41+0 to 41+6 vs 40+0 to 40+6 weeks, was 1.26 with a 95% confidence interval (CI) of 1.07-1.48. Among women with BMI ≥30, the offspring mortality risk in pregnancies lasting 39+0 to 39+2 weeks was significantly above the corresponding risk among women of normal BMI who delivered at 41+0 to 41+2 weeks (ARR = 1.95; 95% CI 1.07-3.56) but no statistically significant heterogeneity was found regarding the magnitude of the association between gestational duration and offspring mortality. The ARR, for Apgar <7 at 5 minutes (41+0 to 41+6 vs 40+0 to 40+6 weeks, regardless of BMI), was 1.36 (95% CI 1.27-1.45). The risk for low Apgar score at 41+0 weeks was 1.5% among all children regardless of maternal BMI. Among children to women with BMI ≥30, this magnitude of risk was found already at 39+3 weeks.

CONCLUSIONS

In primiparous women with obesity the risk of stillbirth or death before 45 postmenstrual weeks were increased throughout all full-term gestational age categories, compared with women with overweight or normal BMI. Children to obese women had the same risk for Apgar scores <7 at 5 minutes compared with women overall at earlier gestational age. The results suggest that maternal BMI needs to be considered when discussing timing of elective induction in term healthy pregnancies of primiparous women.

Trends in labor induction indications: A 20-year population-based study

INTRODUCTION

Use of labor induction has increased rapidly in most middle- and high-income countries over the past decade. The reasons for the stark rise in labor induction are largely unknown. We aimed to assess the extent to which the rising rate of labor induction is explained by changes in rates of underlying indications over time.

MATERIAL AND METHODS

The study was based on nationwide data from the Icelandic Medical Birth Register on 85 620 singleton births from 1997 to 2018. The rate of labor induction and indications for induction was calculated for all singleton births in 1997-2018. Change over time was expressed as relative risk (RR), using Poisson regression with 95% confidence intervals (CI) adjusted for maternal characteristics and indications for labor induction.

RESULTS

The crude rate of labor induction rose from 12.5% in 1997-2001 to 23.9% in 2014-2018 (crude RR = 1.91, 95% CI 1.81-2.01). While adjusting for maternal characteristics had little impact, adjusting additionally for labor induction indications lowered the RR to 1.43 (95% CI 1.35-1.51). Induction was increasingly indicated from 1997-2001 to 2014-2018 by gestational diabetes (2.4%-16.5%), hypertensive disorders (7.0%-11.1%), prolonged pregnancy (16.2%-23.7%), concerns for maternal wellbeing (3.2%-6.9%) and maternal age (0.5%-1.2%). No indication was registered for 9.2% of inductions in 2014-2018 compared with 16.3% in 1997-2001.

CONCLUSIONS

Our results show that the increase in labor induction over the study period is largely explained by an increase in various underlying conditions indicating labor induction. However, indications for 9.2% of labor inductions remain unexplained and warrant further investigation.

Reducing health inequality in Black, Asian and other minority ethnic pregnant women: impact of first trimester combined screening for placental dysfunction on perinatal mortality

OBJECTIVE

To assess the impact of the Fetal Medicine Foundation (FMF) first trimester screening algorithm for pre-eclampsia on health disparities in perinatal death among minority ethnic groups.

DESIGN

A retrospective cohort study from July 2016 to December 2020.

SETTING

A large London teaching hospital.

PATIENTS AND METHODS

All women who underwent first trimester pre-eclampsia risk assessment using either the NICE screening checklist or the FMF multimodal approach. Women considered at high-risk in the FMF cohort were offered 150 mg aspirin before 16 weeks' gestation, serial growth scans and elective birth at 40 weeks.

MAIN OUTCOME MEASURES

Stillbirth, neonatal death and perinatal death rates stratified by screening method and maternal ethnicity.

RESULTS

In the NICE cohort, the perinatal death rate was significantly higher in non-white than white women (7.95 versus 2.63/1000 births, OR 3.035, 95% CI 1.551-5.941). Following the introduction of FMF screening, the perinatal death rate in non-white women fell from 7.95 to 3.22/1000 births (OR 0.403, 95% CI 0.206-0.789), such that it was no longer significantly different from the perinatal mortality rate in white women (3.22 versus 2.55/1000 births, OR 1.261, 95% CI 0.641-2.483).

CONCLUSIONS

First trimester combined screening for placental dysfunction is associated with a significant reduction in perinatal death in minority ethnic women. Health disparities in perinatal death among ethnic minority women demand urgent attention from both clinicians and health policy makers. The data of this study suggest that this ethnic health inequality may be avoidable.