Same-day mifepristone prior to second-trimester induction termination with misoprostol: A retrospective cohort study

To evaluate whether same-day administration of mifepristone and misoprostol, compared with misoprostol alone, reduces the duration of second-trimester induction of labor for termination of pregnancy or increases the rate of fetal expulsion within 24 hours.

We conducted a retrospective analysis of patients undergoing induction of labor for pregnancy termination in the second trimester between 2009 and 2018. We compared patients who received mifepristone on the same day as the first dose of misoprostol to those who received misoprostol alone. The primary outcome was expulsion within 24 hours after the first dose of misoprostol.

Two hundred ninety-eight patients met criteria for inclusion, of whom 94 (31.5%) received same-day mifepristone. Expulsion within 24 hours occurred in 93.6% of the mifepristone-plus-misoprostol group and 79.9% of the misoprostol-only group (RR 1.17, 95%CI 1.07-1.28). Expulsion within 12 hours occurred in 56.4% of the mifepristone-plus-misoprostol group and 34.0% of the misoprostol-only group (RR 1.66, 95%CI 1.28-2.16). After adjusting for demographic and clinical characteristics, the rate of expulsion within 24 hours was similar between groups (RR 1.07, 95%CI 0.92-1.26), while the rate of expulsion within 12 hours remained different (RR 1.69, 95%CI 1.01-2.83). Median time to expulsion was shorter in the mifepristone-plus-misoprostol group than the misoprostol-only group (689 minutes vs 901 minutes, p < 0.001).

Patients who received mifepristone on the same day as misoprostol had a shorter duration of induction termination and higher rate of success within 12 hours.