A randomized clinical trial of prostaglandin E2 intracervical gel and a slow release vaginal pessary for preinduction cervical ripening

OBJECTIVE: Our purpose was to compare the efficacy of 2 different prostaglandin E-2 delivery methods for preinduction cervical ripening. STUDY DESIGN: Ninety patients admitted for labor induction with a Bishop score <8 were randomized to either 0.5 mg prostaglandin E-2 intracervical gel (Prepidil) every 6 hours for 2 doses or 10 mg prostaglandin E-2 slow release vaginal pessary (Cervidil). Oxytocin induction was begun after 12 hours. It was estimated that enrollment of 90 women would be required to identify a 30% difference in the percent delivered in < 24 hours (1 - beta = .80, alpha = .05). Data were analyzed with use of chi(2) analysis or the Student t test. RESULTS: There were 45 subjects in each treatment arm. The percent delivered by 24 hours was 53% with intracervical gel and 63% with vaginal pessary (P = .28). Mean change in Bishop score was 1.8 +/- 1.9 for the intracervical gel versus 3.2 +/- 3.1 for the vaginal pessary (P = .01). No difference was demonstrated in mean time to delivery, 28.3 versus 24.0 hours (P = .19) or percent requiring cesarean section. CONCLUSION: Preinduction cervical ripening with a slow release prostaglandin E-2 vaginal pessary resulted in greater change in Bishop score than with intracervical prostaglandin E-2. There was a trend toward shorter time to delivery with the pessary. There was no statistically significant difference in percent delivered in <24 hours.