Elective Induction of Labor in the 39th Week of Gestation Compared With Expectant Management of Low-Risk Multiparous Women.

Objective: To compare perinatal and maternal outcomes in low-risk multiparous women who underwent elective induction of labor in the 39th week of gestation with those who were expectantly managed.
Methods: We performed a single center retrospective cohort study of low-risk multiparous women delivering nonanomalous singletons between 39 and 42 completed weeks of gestation from 2014 to 2018. The primary outcome was a perinatal composite of death, neonatal respiratory support, a 5-minute Apgar score of 3 or less, and shoulder dystocia. Groups were compared using χ, Fisher exact, two sample t-test, and Wilcoxon rank sum tests, as appropriate. Multivariable logistic regression models were used to adjust for potential confounders.
Results: Of the 3,703 low-risk multiparous women meeting inclusion criteria, 453 (12%) delivered between 39 0/7 and 39 4/7 after an elective induction of labor. Women who underwent elective induction of labor were more likely to be privately insured, non-Hispanic, and weigh more at their first prenatal visit (all P<.01) compared with expectant management. An elective induction of labor was associated with decreased frequency of the perinatal composite morbidity (4.0% vs 7.1%; adjusted odds ratio [aOR] 0.57, 95% CI 0.34-0.96) compared with expectant management. Fewer cesarean deliveries occurred among women in the elective induction of labor group (5.1% vs 6.6%; aOR 0.60, 95% CI 0.37-0.97). Other maternal outcomes (hypertensive disorders, chorioamnionitis, and operative vaginal deliveries) as well as neonatal intensive care unit admissions were not different between groups.
Conclusion: Elective induction of labor in low-risk multiparous women in the 39th week of gestation was associated with decreased perinatal morbidity and a lower frequency of cesarean delivery compared with expectant management.