Labor induction with misoprostol versus dinoprostone:

A meta-analysis of seven randomized trials

Abstract

OBJECTIVE: To compare the efficacy and safety of two prostaglandin analogs, misoprostol and dinoprostone, for labor induction of third trimester pregnancies with
fetus and cervices unfavorable to oxytocin, as reported by recently published studies.

METHODS: Seven randomized, controlled and prospective studies, comparing intravaginally applied misoprostol (n=500) with dinoprostone (n=498) were selected
from Medline. For each variable analyzed in each of the seven studies reviewed, we used SerSimonian and Laird’s method to evaluate the homogeneity of treatment
effects. To analyze the results of each clinical trial, the relative risk was calculated with a 95% Confidence Interval; a “common” RR for different outcomes was also
calculated using the Mantel-Haens method, with the SAS statistical package. The following outcomes were evaluated in our study: need for oxytocin augmentation;
need for cesarean section; meconium passage; 1- and 5-minute Apgar scores.

RESULTS: When misoprostol was used instead of dinoprostone, there was a decrease of approximately 50% in the need to use oxytocin (RR = 0.55; 0.49-0.63). No difference was found regarding the need to perform cesarean sections in the misoprostol group when compared to the dinoprostone group (RR = 1.04; 0.81-1.34). There was a slightly higher incidence of meconium passage among the group that used misoprostol (RR = 1.39; 1.03-1.86). No significant difference in the incidence of Apgar score smaller than 7 was observed between the misoprostol or dinoprostone group, either at the 1st (RR = 1.36; 0.92-2.26) or at the 5th minute (RR = 1.39; 0.36-5.36).

CONCLUSIONS: For the labor induction in third trimester pregnacies, with live fetus and unfavorable cervices, misoprostol is as effective and as safe as dinoprostone. A 50 mg dose of misoprostol may cause a higher incidence of meconium passage, however, it doesn’t compromise the perinatal performance of the newborn. The cost of misoprostol treatment was significantly lower than the cost of dinoprostone treatment according to the three studies that assessed this variable.