Elective Induction Compared With Expectant Management in Nulliparous Women With a Favorable Cervix

Abstract

A number of observational studies have demonstrated increased rates of cesarean delivery in nulliparous women, regardless of favorable or unfavorable cervical status. However, most used a design in which labor induction was compared with spontaneous labor at a given gestational age, not with expectant management, which is a more appropriate clinical comparison. A recent retrospective study demonstrated that nulliparous women who were electively induced had decreased rates of cesarean delivery in comparison to those who were expectantly managed. However, this study did not control for cervical status. In the present study, the investigators hypothesized that after controlling for cervical status, women who were electively induced would have a higher likelihood of cesarean delivery than those who were expectantly managed. A perinatal database was used to identify a population of singleton nulliparous women with a favorable cervix who underwent elective induction of labor (n = 294) or expectant management (n = 294) at 39 to 40 5/7 weeks of gestation, between 2006 and 2008. The elective induction and expectantly managed groups had similar demographic features except that the elective induction group had a slightly higher body mass index (29.4 ± 5.0 vs. 28.2 ± 3.6) and slightly higher Bishop's score (6.8 ± 1.6 vs. 5.8 ± 1.0). No significant differences were observed between the two groups in rates of cesarean delivery, the primary outcome (induction: 20.8% vs. expectant management: 20.1%; P = 0.84). The results remained stable following adjustment for potential confounding variables. Moreover, no significant differences were found for other maternal outcomes (operative vaginal delivery, chorioamnionitis, third- and fourth-degree lacerations, or postpartum hemorrhage), or neonatal outcomes (arterial cord pH less than 7.0, Apgar score less than 4 at 5 minutes, or admission to intensive care unit). The duration of labor and delivery was longer among women undergoing an elective labor induction (median: 12.7 hours) compared with those given expectant management (median: 9 hours; P < 0.001). These findings demonstrate that the likelihood of cesarean delivery among nulliparous women with a favorable cervix is similar for elective induction and expectant management.