Induction of labor at full term in uncomplicated singleton gestations: a systematic review and metaanalysis of randomized controlled trials

The aim of this study was to evaluate the risk of cesarean and any maternal and perinatal effects of a policy induction of labor in uncomplicated full-term singleton gestations. Searches were performed in an electronic database with the use of a combination of text words related to "induction" and "cesarean section" from inception of each database through December 2014. We included all randomized controlled trials of uncomplicated singleton gestations at full term (ie, between 39 weeks 0/7 days and 40 weeks 6/7 days) with intact membranes randomized to induction of labor or control (ie, expectant management). The primary outcome was the incidence of cesarean delivery. The summary measures were reported as risk ratio (RR) with 95% confidence interval (CI). Five randomized controlled trials, including 844 women, were analyzed. Full-term vertex singleton gestations receiving induction of labor had similar incidence of cesarean delivery compared to controls (9.7% vs 7.5%; RR, 1.25; 95% CI, 0.75-2.08). Rates of spontaneous (75.9% vs 80.2%; RR, 0.95; 95% CI, 0.87-1.02) and operative (13.1% vs 10.6%; RR, 1.22; 95% CI, 0.83-1.81) vaginal delivery were also similar. Induction was associated with similar rates of chorioamnionitis (9.6% vs 8.0%; RR, 1.17; 95% CI, 0.38-3.39), but statistically significantly less blood loss (mean difference -57.59 mL; 95% CI, -83.96 to -31.21) compared to controls. Regarding neonatal outcomes, induction was associated with a significantly lower rate of meconium-stained amniotic fluid (4.0% vs 13.5%; RR, 0.32; 95% CI, 0.18-0.57) and significantly lower mean birthweight (mean difference -135.51 g; 95% CI, -205.24 to -65.77) compared to control group. Induction of labor at full term in uncomplicated singleton gestations is not associated with increased risk of cesarean delivery and has overall similar outcomes compared to expectant management.