A comparison of orally administered misoprostol to intravenous oxytocin for labor induction in women with favorable cervical examinations

Abstract

Objective: The purpose of this study was to compare orally administered misoprostol with intravenous oxytocin infusion for labor induction in women with favorable cervical examinations (defined as a Bishop score of 6 or more).

Study design: One hundred ninety-eight women with indications for labor induction and favorable cervical examinations were assigned randomly to receive oral misoprostol or oxytocin induction. Misoprostol, 100 mg, was administered every 4 hours up to 6 doses, or intravenous oxytocin was administered by standardized protocol.

Results: One hundred ten (55.6%) women received misoprostol; 88 (44.4%) received intravenous oxytocin. There was no statistically significant difference in the average interval from start of induction to vaginal delivery, being longer in the misoprostol group (789.4 +/- 510.2 minutes) than in the oxytocin group (654.0 +/- 338.2 minutes, P=.19, log-transformed data). Two women had tachysystole develop in each treatment group. More women in the misoprostol group experienced hyperstimulation (7/110, 6.4%) than in the oxytocin group (0/88, P=.02, Fisher exact test). Nine (8.1%) misoprostol-treated women and 8 (9.1%) oxytocin-treated women underwent cesarean deliveries (P=.82). There was a presumed uterine rupture in a misoprostol-treated multipara women. There were no statistically significant differences in neonatal outcomes between the groups.

Conclusion: Oral misoprostol offers no benefit over intravenous oxytocin for labor induction in women with favorable cervical examinations. It is associated with a higher likelihood of uterine hyperstimulation and may increase the risk of uterine rupture.