OBJECTIVE: To evaluate the effectiveness of four commonly used induction methods.
METHODS: This randomized trial compared four induction methods: misoprostol alone, Foley alone, misoprostol–cervical Foley concurrently, and Foley–oxytocin concurrently. Women undergoing labor induction with full-term (37 weeks of gestation or greater), singleton, vertex-presenting gestations, with no contraindication to vaginal delivery, intact membranes, Bishop score 6 or less, and cervical dilation 2 cm or less were included. Women were enrolled only once during the study period. Our primary outcome was time to delivery. Neither patients nor health care providers were blinded to assigned treatment group because examinations are required for placement of all methods; however, research personnel were blinded during data abstraction. A sample size of 123 per group (n5492) was planned to compare the four groups pairwise (P#.008) with a 4-hour reduction in delivery time considered clinically meaningful.