Pretreatment With Mifepristone Compared With Misoprostol Alone for Delivery After Fetal Death Between 14 and 28 Weeks of Gestation: A Randomized Controlled Trial

OBJECTIVE: To assess the efficacy of pretreatment with mifepristone before misoprostol, compared with misoprostol alone, for termination of pregnancy after a fetal death in the second trimester. METHODS: This prospective, double blind, placebo-controlled trial randomized women requiring a termination of pregnancy after fetal death between 14 and 28 weeks of gestation to placebo or 200 mg mifepristone orally 24-48 hours before the termination of pregnancy with misoprostol (400 micrograms every 6 hours vaginally for women at 24 weeks of gestation or less, and 200 micrograms every 4 hours vaginally for women at 24 weeks of gestation or more). Based on a median labor with misoprostol alone in the second trimester of 13 hours, a sample size of 116 women per group was planned to compare the primary outcome of time from administration of misoprostol to delivery. The trial was ceased after 66 women were enrolled secondary to prolonged time to achieve recruitment. RESULTS: From April 2013 to November 2016, 66 women were randomized (34 to placebo and 32 to mifepristone). There were no differences in the characteristics between the two groups. The median time for the primary outcome of administration of misoprostol to delivery in the placebo group was 10.5 hours, compared with 6.8 hours in the treatment group (hazard ratio 2.41 95% CI 1.39-4.17, P=.002). Women in the placebo group required more doses of misoprostol (3.4 vs 2.1, P=.002) and more misoprostol overall (1,181.8 micrograms, vs 767.7 micrograms, P=.003). There was no difference in maternal complications between the two groups. Women in the mifepristone group reported improved perception of the procedure. CONCLUSION: The sequential use of mifepristone and misoprostol for the termination of pregnancy after fetal deaths between 14 and 28 weeks of gestation reduces the time to delivery, compared with the use of misoprostol alone, with no worsening of maternal complications. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12612000884808. Copyright © 2021 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.