A double-blind comparison of the safety and efficacy of intravaginal misoprostol and prostaglandin E2 to induce labor.

Abstract

Our purpose was to compare the safety and efficacy of intravaginally administered misoprostol versus prostaglandin E2 for labor induction in a double-blind, randomized trial. One hundred three patients with indications for labor induction (including prelabor rupture of membranes) were randomized and received either misoprostol 50 micrograms or prostaglandin E2 (dinoprostone) 3 mg intravaginally. The dose was repeated 6, 24, and 30 hours after the first dose until active labor was achieved. For proper blinding, the drugs were prepared as identical-looking vaginal tablets. With use of a random number-generated table 52 patients were allocated to the misoprostol group and 51 to the prostaglandin E2 group. After exclusion of 3 patients, 50 in each group were evaluated. Delivery within 24 hours after administration occurred more often in the misoprostol group (70% vs 46% in the prostaglandin E2 group, p = 0.009), and fewer patients in this group needed more than two doses (12% vs 30%, p = 0.027). No difference in cesarean section rate (12% vs 14%, p = 0.67), fetal heart rate anomalies (33% vs 34%, p = 0.89), tachysystole (8% vs 14%, p = 0.37), hyperstimulation syndrome (0% vs 2%, not significant), meconium passage (28% vs 18%, p = 0.22), and fetal outcome (Apgar score at 1 and 5 minutes, arterial and venous umbilical cord blood pH, transfer to neonatal intensive care unit) was noted between the two groups. Intravaginal misoprostol is a safe drug for labor induction with superior effectiveness compared with intravaginal prostaglandin E2.