The impact of labor induction at 39 weeks gestation compared with expectant management on maternal and neonatal morbidity in low-risk women: A United States of America Cohort Study

Abstract

Objective: To determine maternal and neonatal morbidity associated with induction of labor at 39 weeks compared with expectant management through 42 weeks. Design: Cohort study Setting & Population: Low risk American women who delivered between 39 and 42 weeks in 2015 to 2017. Methods: Data was abstracted from the national vital statistics database. Multivariable log-binomial regression analysis was conducted to estimate the relative risk of morbidity. Main Outcome Measures: Maternal morbidity included Triple I, blood transfusion, ICU admission, uterine rupture, cesarean hysterectomy, and cesarean delivery. Neonatal morbidity included 5 minute Apgar ≤3, prolonged ventilation, seizures, NICU admission, and neonatal death. Results: A total of 1,885,694 women were included for analysis. Women undergoing induction of labor at 39 weeks were less likely to develop Triple I (p-value < 0.001; aRR 0.66; 95% CI [0.64-0.68]) and require a cesarean section (p-value <0.01; aRR 0.69l 95% CI [0.68-0.69]) than the expectant management group. There was a small, but significant increase in cesarean hysterectomy in the induction group (p-value <0.01; aRR 1.32; 95% CI [1.05-1.65]). Neonates of the induction group were less likely to have 5 minute Apgar ≤3 (p-value < 0.01; aRR 0.69; 95% CI [0.64-0.74]), prolonged ventilation (p-value < 0.01; aRR 0.77; 95% CI [0.72-0.82]), NICU admission (p-value < 0.01; aRR 0.80; 95% CI [0.79-0.82]), and/or neonatal seizures (p-value <0.01; aRR 0.80; 95% CI [0.66-0.98]) compared to the expectant management group. Conclusions: Induction of labor at 39 weeks gestation compared with expectant management is not harmful and has maternal and neonatal benefits.