Background: Misoprostol, a prostaglandin E1 analog registered for the prevention of gastric ulcers in NSAID-drug users, has been reported to be more effective for labor induction than the standard prostaglandin, dinoproston after vaginal application. There have been some concerns about possible hyperstimulation of the uterine activity and about the safety for the fetus with this new drug.
Methods: Two hundred and ten patients, 36 weeks pregnant or more, with an unfavorable cervix, single pregnancy, and intact membranes were randomized to receive misoprostol, 50 micrograms intravaginally every 6 hours, or dinoproston 0.5 mg intracervically every 12 hours for a maximum of 24 hours, for labor induction.
Results: Time from induction to delivery was shorter in both primigravidae and multigravidae after the application of misoprostol than dinoproston and failed induction was more common after dinoproston than after misoprostol. There were no differences in the condition of the newborns in the two groups, according to Apgar score, umbilical artery pH or referral to the neonatal unit, even if there were more operative deliveries for suspected fetal asphyxia after misoprostol than after dinoproston. We did not find any significant difference in the frequency of uterine hyperstimulation between the two groups.
Conclusions: In the dosage used, misoprostol seems to be an effective agent for induction of labor in patients with an unfavorable cervix. Low cost and ease of administration make this drug a promising alternative for this purpose. Surprisingly, there is little interest from the manufacturer to promote the use of this drug for labor induction.