Objective: To compare effectiveness of misoprostol and ethacridine lactate with or without oxytocin in second-trimester medical abortions.
Subjects and methods: A randomized prospective study. A total of 388 women with genetic indications for termination of pregnancy at 13-24 weeks of gestation were recruited. Group I (n=85) were treated with extra-amniotic ethacridine lactate, 10 ml instilled per gestational week, to a maximum of 200 ml. Group II (n=93) were treated with misoprostol administered intravaginally (200 microg), followed by 100 microg of oral misoprostol 4 hourly for 24 h. Group III (n=102) were treated with a combination of ethacrine lactate and oxytocin. An initial dose of 6 mU/min oxytocin was given, followed by additional 6 mU/min doses every 20 min. Group IV (n=96) were treated with a combination of misoprostol and oxytocin administered in a similar way as in group III. The main outcome measures were time to induce abortion, side effects, and failure/success rates.
Results: The mean time to induce abortion was 14.2+/-3.6, 13.2+/-3.4, 10.8+/-2.6, and 9.9+/-2.4 h in groups I, II, III, and IV, respectively (p<0.001). Addition of oxytocin to ethacridine lactate did not decrease the risk of prolongation of induction beyond 24 h but use of oxytocin with misoprostol did reduce the risk of induction beyond 24 h (OR: 0.46, 95%CI: 0.21-1, p<0.05). The occurrence of minor side effects was similar in all groups.
Conclusion: Addition of oxytocin to ethacridine lactate or misoprostol significantly decreases the length of time to induce abortion without supplementary side effects.