Outpatient misoprostol compared with dinoprostone gel for preinduction cervical ripening: a randomized controlled trial

Abstract

Objective: To determine whether a single outpatient dose of intravaginal misoprostol (versus intracervical dinoprostone gel) reduces the oxytocin use for induction. Despite the numerous trials examining misoprostol for induction, the efficacy of a single outpatient dose of misoprostol followed by oxytocin induction is unknown.

Methods: Patients with a term, vertex, singleton pregnancy and a Bishop score of 6 or less were randomly assigned to receive misoprostol (n = 42, 0.25 microg intravaginally) or dinoprostone gel (n = 42, 0.5 mg intracervically) the evening before oxytocin induction. Patients were monitored for 3 hours after administration and discharged to home if fetal assessment was reassuring, for readmission the next morning for oxytocin. Primary outcomes were oxytocin dose, time, and dose intensity (dose divided by duration). Secondary outcomes were incidence of labor, uterine hyperstimulation, cesarean delivery, Apgar score. Statistics used were chi(2), Student t test, Mann-Whitney rank sum test, and Fisher exact test. P < .05 was accepted as statistically significant.

Results: A single dose of misoprostol significantly decreased the cumulative dose of oxytocin, the cumulative time of oxytocin administration, and the dose intensity of oxytocin (dose divided by time). Data are as follows (mean +/- standard error of the mean): oxytocin dose-dinoprostone 10,929 +/- 219 mU, misoprostol 6,081 +/- 170 mU, P = .008; oxytocin time-dinoprostone 798 +/- 11 minutes, misoprostol 531 +/- 11 minutes, P = .009; dose intensity-dinoprostone 11.3 +/- 0.1 mU/min, misoprostol 7.4 +/- 0.2 mU/min, P = .003. Misoprostol induced labor during the ripening period in 19 of 41 of patients, compared with 6 of 42 after dinoprostone (P = .002). There was no difference in cesarean delivery (dinoprostone, 8/42; misoprostol, 9/42; P = 1.00). There was no difference in short-term neonatal outcome. No patient had hyperstimulation or required cesarean delivery for nonreassuring fetal assessment during the ripening period.

Conclusion: A single dose of misoprostol administered in the outpatient setting significantly decreases oxytocin use, largely due to labor within the ripening period.