Dosing interval between mifepristone and misoprostol in second and third trimester termination.

Prodan N, Breisch J, Hoopmann M, Abele H, Wagner P, Kagan KO.

Dec 2018
OBJECTIVE: To compare several strategies for second trimester labor induction for termination of pregnancy (TOP) using misoprostol and mifepristone and to determine which one is more effective in accelerating the time to delivery. METHOD: This was a retrospective study in which pregnancies that underwent second and third trimester TOP due to fetal anomalies between 2007 and 2017 were classified into a group that received misoprostol alone, a group that received mifepristone followed by misoprostol on the same day, one where misoprostol was given 1 day after mifepristone and one where the medications were administered 2 days apart. The primary outcome measure was the induction to delivery interval. RESULTS: 481 pregnancies fulfilled the inclusion criteria. In 140 cases, mifepristone was not administered. 341 women received mifepristone prior to induction, which was administered on the day of induction in 85 cases, and 1 or 2 days prior to induction in 140 and 19 cases. Median time interval between first induction and delivery was 15.0 (IQR 10.0-24.1) h in case no mifepristone was given and 13.2 (9.7-18.2) h if mifepristone was given on the same day and 9.3 (6.6-14.9) and 10.5 (7.2-22.3) h, if mifepristone was given 1 or 2 days prior to induction. After 24 h, the proportion of terminated pregnancies in each of the four groups was 75.0, 83.5, 93.2 and 78.9%. CONCLUSION: A 1 day interval between mifepristone and misoprostol is more effective in second and third trimester TOP compared to other strategies in terms of reducing the induction to abortion interval.