Maternal and perinatal complications by day of gestation after spontaneous labor at 40-42 weeks of gestation

Maternal body mass index and post-term birth: a systematic review and meta-analysis

Post-term birth is a preventable cause of perinatal mortality and severe morbidity. This review examined the association between maternal body mass index (BMI) and post-term birth at ≥42 and ≥41 weeks' gestation. Five databases, reference lists and citations were searched from May to November 2015. Observational studies published in English since 1990 were included. Linear and nonlinear dose-response meta-analyses were conducted by using random effects models. Sensitivity analyses assessed robustness of the results. Meta-regression and sub-group meta-analyses explored heterogeneity. Obesity classes were defined as I (30.0-34.9 kg m-2 ), II (35.0-39.9 kg m-2 ) and III (≥40 kg m-2 ; IIIa 40.0-44.9 kg m-2 , IIIb ≥ 45.0 kg m-2 ). Searches identified 16,375 results, and 39 studies met the inclusion criteria (n = 4,143,700 births). A nonlinear association between maternal BMI and births ≥42 weeks was identified; odds ratios and 95% confidence intervals for obesity classes I-IIIb were 1.42 (1.27-1.58), 1.55 (1.37-1.75), 1.65 (1.44-1.87) and 1.75 (1.50-2.04) respectively. BMI was linearly associated with births ≥41 weeks: odds ratio is 1.13 (95% confidence interval 1.05-1.21) for each 5-unit increase in BMI. The strength of the association between BMI and post-term birth increases with increasing BMI. Odds are greatest for births ≥42 weeks among class III obesity. Targeted interventions to prevent the adverse outcomes associated with post-term birth should consider the difference in risk between obesity classes.

Maternal and neonatal outcomes following induction of labor: a cohort study

OBJECTIVE

To evaluate maternal and neonatal outcomes associated with birth at term by week of gestational age and also by onset of labor.

DESIGN

Cohort study.

SETTING

A state-wide perinatal outcome database.

POPULATION

28,626 women with spontaneous onset of labor, induction of labor for recognized indications and induction of labor for non-recognized indications.

METHODS

Cohort study utilizing a validated dataset comparing outcomes with type of onset of labor using a log binomial model.

MAIN OUTCOME MEASURES

Cesarean section, assisted vaginal birth, important measures of maternal and neonatal morbidity.

RESULTS

Induction of labor for non-recognized indications was associated with a significantly increased risk of a range of outcomes, including cesarean section (RR 1.67, 95% CI 1.55-1.80). The lowest risk of adverse maternal and infant outcome occurred with birth between 38 and 39 weeks and with the spontaneous onset of labor.

CONCLUSIONS

Induction of labor for non-recognized indications at term is associated with an increased risk of adverse outcomes. Caution is warranted with a liberal policy of induction of labor at term in an otherwise uncomplicated pregnancy.