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.