Oral misoprostol vs. intravaginal prostaglandin E2 for preinduction cervical ripening. A randomized trial.

Objective: To compare orally administered misoprostol with intravaginal prostaglandin E2 for cervical ripening and labor induction.
Study Design: Patients presenting with medical or obstetric indications for labor induction whose Bishop's score was < or = 6 were randomly allocated to receive either 50 micrograms of oral misoprostol or 4 mg of intravaginal prostaglandin E2. If adequate cervical ripening (Bishop score of 9 or cervical dilatation of 3) or active labor did not ensue, repeat doses of each medication were administered every four hours. A maximum of six doses of either oral misoprostol or intravaginal prostaglandin E2 was permitted. Intravenous oxytocin was subsequently administered according to a standardized infusion protocol.
Results: Sixty patients were enrolled, with 29 randomized to the oral misoprostol arm and 31 to the prostaglandin E2 group. The data on 58 patients were eligible for analysis. Delivery occurred within 48 hours in 96.4% (27/28) of those administered oral misoprostol as compared to 76.7% (23/30) of those who received intravaginal prostaglandin E2 (P = .03). The mean time intervals from the start of induction to delivery were similar between the two groups (1,496 +/- 120 vs. 1,723 +/- 230 minutes, P = .40). No statistically significant differences existed between the two groups with respect to intrapartum complications, tachysystole, uterine hyperstimulation or adverse neonatal outcomes.
Conclusion: Oral administration of misoprostol is an effective alternative to intravaginal prostaglandin E2 for preinduction cervical ripening.