A Comparison of Oral Misoprostol With Vaginal Misoprostol Administration in Second-Trimester Pregnancy Termination for Fetal Abnormality

Abstract

In Brief OBJECTIVE To compare the clinical efficacy and side effects of oral misoprostol with vaginal misoprostol for second-trimester pregnancy termination. METHODS A randomized clinical trial of medical pregnancy termination between 14 and 26 weeks' gestation was conducted. Three misoprostol regimens were compared: 400 μg vaginally at 6-hour intervals (group 1), 400 μg orally at 3-hour intervals (group 2), and a loading dose of 600 μg vaginally followed by 200 μg orally at 3-hour intervals (group 3). A sample size of 225 women was required for equivalence of the three regimens, with an interim safety analysis planned at 80 women. RESULTS A significant difference between the groups was evident at the interim safety analysis and the study ceased. The subset of 84 women recruited before the study closure is described. There was a significant difference in the median time to achieve delivery among the three groups: group 1, 14.5 hours (95% confidence interval 12.0, 16.9), versus group 2, 25.5 hours (13.5, 23.8), versus group 3, 16.4 hours (interquartile range 14.2–37.3) (P = .042). Within 24 hours of commencement 85.7% of women in group 1, 44.8% in group 2, and 74.1% in group 3 delivered (P = .003). At 48 hours 0% in group 1, 20.7% in group 2, and 3.7% in group 3 were undelivered (P = .011). There was no difference in women's perceptions of the termination process. CONCLUSION In second-trimester pregnancy termination, a vaginal misoprostol regimen of 400 μg every 6 hours was 1.9 times more likely to result in delivery within 24 hours from commencement than an oral regimen of 400 μg every 3 hours. In second-trimester pregnancy termination for fetal abnormality, avaginal misoprostol regimen was 1.9 times more likely to result indelivery within 24 hours from commencement than an oral regimen.