Elective Induction of Labor Compared With Expectant Management of Nulliparous Women at 39 Weeks of Gestation: A Randomized Controlled Trial

The purpose of the current study was to examine the effect of elective induction of labor in nulliparous women with an unfavorable cervix at 39 weeks of gestation on cesarean delivery rates. A randomized controlled trial (RCT) was conducted at a military tertiary care medical center that serves active-duty as well as beneficiaries of active-duty and retired military personnel. All women who met the inclusion criteria of between 38 0/ 7 weeks and 38 6/ 7 weeks of gestation were invited to participate. Eligible women were at least 18 years of age, nulliparous, with a singleton gestation and a Bishop score of 5 or less. The induction of labor group was induced within 1 week of enrollment but not before 39 0/ 7 weeks of gestation. The control group continued routine prenatal care with admission for labor or obstetric indication. The primary outcome was cesarean delivery. Assuming a 20% rate in women in a control group, 80% power, and a goal to detect a 2-fold increase to 40% in the induction of labor group, 162 patients were needed. Secondary outcomes included the following: number of scheduled prenatal visits after randomization, unscheduled clinic or triage visits, number of antepartum fetal testing appointments, gestational age and Bishop score at admission, admission diagnosis (including indication for induction if applicable), and indications for operative deliveries. Between 2010 and 2014, a total of 916 patients were assessed for study eligibility, and 162 were enrolled. The study patients were primarily young and white, and the baseline characteristics were similar between groups. The cesarean delivery rate in the induction of labor group was 30.5% (25/ 82) compared with 17.7% (14/ 79) in the expectant management group (relative risk, 1.72; 95% confidence interval, 0.96-3.06). The results of the study concluded that in nulliparous women with a Bishop score of 5 or less elective induction after 39 0/ 7 weeks of gestation compared with expectant management of pregnancy did not double the rate of cesarean delivery.