One- and two-day mifepristone-misoprostol intervals for second trimester termination of pregnancy between 13 and 16 weeks of gestation

Objective

To compare the efficacy of 1-day and 2-day mifepristone and misoprostol intervals for second trimester termination of pregnancy between 13 and 16 weeks.

Methods

A prospective randomized cohort study of 100 women who underwent voluntary termination between 13 and 16 weeks of gestation. Patients were randomly assigned to receive 200 mg of oral mifepristone, followed 1 day (group 1) or 2 days (group 2) later by 600 μg of vaginal misoprostol. All patients received 400 μg of oral misoprostol every 6 hours for a maximum of 2 doses. Main outcome measure was successful abortion rate at 24 hours after the start of misoprostol treatment. Secondary outcome measures were induction-to-abortion interval and frequency of adverse events.

Results

The 24-hour successful abortion rate was similar between groups 1 and 2 (47 [94%] vs 50 [100%]; P = 0.241). The mean misoprostol-to-abortion interval was also similar (7.0 ± 3.0 vs 6.8 ± 4.3 hours; P = 0.744). Among the 86 patients for whom histological examination of the products of conception was performed, retained chorionic villi rates were higher in the 1-day regimen group compared with the 2-day regimen group (46.2% [18/39] vs 29.8% [14/47]; P < 0.001).

Conclusion

A 2-day mifepristone-misoprostol interval resulted in fewer incomplete abortions than a 1-day interval for second trimester termination of pregnancy between 13 and 16 weeks.