HR Siswosudarmo, Budi Susetyo and Zain Alkaff
Department of Obstetrics and Gynecology
Faculty of Medicine, Gajah Mada University
Yogyakarta
Background: Misoprostol has been widely used to induce labor. It is more superior to oxytocin especially in an unripe cervix. Recent reports suggest that 50 mg misoprostol produces some serious side effect from hyperstimulation to the uterine rupture leading to death. A smaller dose should then be investigated.
Objectives: To compare 25 mg misoprostol vs. 50 mg for induction of labor in terms of effectiveness and safety.
Material and method: A double blind randomized controlled trial was used in this study. A total of 136 eligible pregnant women were randomly assigned to a treated (25 mg) and a control group (50mg). The drug is given by posterior fornix application. The outcomes being studied were effectiveness, represented by numbers of patients who arrived to fully dilated cervix within 24 hours after the first application, type of delivery, maternal and perinatal side effects.
Results: Both groups were comparable in terms of maternal and pregnancy age, indication of induction, number of ruptured membrane, and Bishop’s score. There was no difference between treated and control group in the rate of success and vaginal delivery i.e. 79.7% vs. 89.6% and 88.4% vs. 85% respectively. The duration from start of induction to fully dilated cervix was statistically longer in the treated group, but not clinically (12.05 + 5.04 vs. 10.29 + 4.47 hours). Tachysystole was significantly lower in the treated group (1.40% vs. 9.00%, p = 0.05) and no hypertonus was found. Hyperstimulation syndrome and fetal distress were clinically lower in the treated group (1.4% vs. 7.5% and 4.3% vs. 11.5%) but not statistically. No difference was found in the rate of first minute asphyxia i.e. 20.3% in treated group vs. 26.9% in the control groups.
Conclusion: The dose of 25 mg misoprostol was proven to be as effective as 50 mg, fewer side effects, but it was somewhat longer to achieve a full dilatation.
Key words: induction of labor, misoprostol, doses, effectiveness and side effects.