Induction of labor with misoprostol in pregnancies with advanced maternal age

Abstract

Objective: The objective was to compare the efficacy and complications of intravaginal misoprostol application with oxytocin infusion for induction of labor in advanced aged pregnancies with a Bishop score of < 6.

Study design: A hundred advanced aged (> or = 35 years) pregnant patients with a Bishop score of < 6 were randomized into two groups. The first group (50 patients) received 50 microg intravaginal misoprostol four times with 4 h intervals and the second group received oxytocin infusion for induction of labor starting from 2 mIU/min and was increased every 30 min with 2 mIU/min increments up to a maximum of 40 mIU/min. The time from induction to delivery, the route of delivery, fetal outcome, and maternal complications were recorded. Statistical analyses were performed using the Mann-Whitney U, Chi-squared and t tests to determine differences between the two groups. A p value < or = 0.05 was considered significant.

Results: Misoprostol was superior for induction of labor in advanced aged pregnancies with Bishop score of < 6, as the mean time from induction to delivery was 9.61 +/- 4.12 h and 11.46 +/- 4.86 h in the misoprostol and oxytocin groups respectively, with a significant difference between the groups (p = 0.04). The rate of vaginal delivery was higher in the misoprostol group (84.0%) than in the oxytocin group (80.0%), but the difference did not reach significance (p = 0.60). The rates of placental abruption and postpartum hemorrhage were similar in both groups and no cases of uterine rupture occurred. The 1- and 5-min mean Apgar scores were 6.98 +/- 1.17 to 9.08 +/- 0.99 and 6.88 +/- 1.81 to 9.00 +/- 1.35 in the misoprostol and oxytocin groups respectively, with no significant differences between the groups (p = 0.74, p = 0.83). No cases of asphyxia were present. The rate of admission to the neonatal intensive care unit was similar in both groups.

Conclusion: Intravaginal misoprostol seems to be an alternative method to oxytocin in the induction of labor in advanced aged pregnant women with low Bishop scores, as it is efficacious, cheap, and easy to use. But large studies are necessary to clarify safety with regard to the rare complications such as uterine rupture.