Misoprostol with Foley Bulb Compared with Misoprostol Alone for Cervical Ripening: A Randomized Controlled Trial

OBJECTIVE:To test the hypothesis that cervical ripening using a combination of misoprostol and a transcervical Foley bulb leads to delivery within a shorter time compared with misoprostol alone.METHODS:This randomized controlled trial was offered to women admitted for cervical ripening. Inclusion criteria were gestational age 37 weeks or greater with intact membranes, singleton fetus, cephalic presentation, and Bishop score 6 or less. Exclusion criteria included, among others, prior uterine surgery, ruptured membranes, and any contraindication to vaginal delivery. Patients were randomized to cervical ripening using misoprostol and a transcervical Foley bulb simultaneously or misoprostol alone. Primary outcome was time from placement of the misoprostol to delivery. Secondary outcomes included time to active phase, time from active phase to delivery, cesarean delivery rate, uterine tachysystole, estimated blood loss, chorioamnionitis, cord pH, 5-minute Apgar score, and neonatal intensive care unit admission. Sample size calculation revealed that 94 participants were required in each group to detect a 3-hour difference with 80% power and α error of 0.05. Intention-to-treat analysis was performed.RESULTS:From September 2015 to July 2016, a total of 200 patients were randomized, 100 to each group. There were no differences between groups with respect to parity, body mass index, gestational age, Bishop score, birth weight, or indication for induction. Time to delivery was significantly shorter in the combined misoprostol-transcervical Foley group: 15.0 (11.0-21.8) hours (median [interquartile range]) vs 19.0 (14.0-27.3) hours in the misoprostol-only group (P=.001). This time difference remained significant after subanalysis by parity or after excluding cesarean deliveries. There was no difference between groups with respect to the rate or indication for cesarean delivery, estimated blood loss, rate of tachysystole, chorioamnionitis, or neonatal outcomes.CONCLUSION:Cervical ripening using misoprostol in combination with a transcervical Foley bulb is an effective method to shorten the course of labor compared with misoprostol alone.