Time-to-delivery and delivery outcomes comparing three methods of labor induction in 7551 nulliparous women: a population-based cohort study

Objective: Determine time-to-delivery and mode-of-delivery in labor induction among women with unripe cervix. Study design: 7551 nulliparous women with singleton deliveries, ⩾37 weeks, Bishop Score ⩽6, induced with dinoprostone, misoprostol or transcervical single balloon catheter. Linear regression analysis was used to estimate mean time-to-delivery with β-estimates and 95% confidence intervals with adjustments. Multivariable logistic regression analysis was used to calculate odds of cesarean delivery, instrumental vaginal delivery, maternal and neonatal outcomes. Results: Adjusted mean time-to-delivery was 6.9 and 1.5 h shorter, respectively, when inducing labor with balloon catheter (mean 18.3 h, β −6.9, 95% confidence intervals; −7.6 to −6.3) or misoprostol (mean 23.7 h, β −1.5, 95% confidence intervals; −2.3 to −0.8) compared with dinoprostone (mean 25.2 h). There were no significant differences in adverse maternal or infant outcomes between induction methods. Conclusions: Balloon catheter is the most effective induction method with respect to time-to-delivery in nulliparous women at term compared with prostaglandin methods.