Early pregnancy loss: Pretreat with mifepristone?

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Demographics. The mean age of the study participants in both groups was ~30 years, and there was a similar percentage of participants by self-reported race and ethnicity in both groups (~44% black, ~35% white, and ~25% Hispanic). The majority of participants in both groups were at 6 to 8 weeks’ gestation and had been pregnant at least 3 times.

Results. Researchers were able to evaluate 297 women at the initial follow-up. Of the women who received mifepristone and misoprostol, 83.8% (124 of 148 women; 95% confidence interval [CI], 76.8-89.3) had complete expulsion within 1 to 3 days, compared to 67.1% (100 of 149 women; 95% CI, 59-74.6) in the misoprostol alone group. The number needed to treat with mifepristone and misoprostol to achieve complete expulsion at the first follow-up visit was 6. The percentage of patients receiving uterine aspiration was lower in the mifepristone and misoprostol group (8.8%) than in the misoprostol alone group (23.5%; relative risk = 0.37; 95% CI, 0.21-0.68). There were no significant differences in adverse events including bleeding intensity, pelvic infection, or pain.


A high-quality RCT demonstrates improved efficacy

Prior studies that have looked at combined mifepristone and misoprostol treatment for early pregnancy loss had heterogeneity in outcome definitions and study designs leading to variable reports of effectiveness.1,5 This is the first high-quality, randomized trial to demonstrate the safety and efficacy of oral mifepristone pretreatment prior to misoprostol vaginal administration in the medical management of early pregnancy loss.


Would a placebo group—or other forms of misoprostol—change the results?

The study did not include a placebo group; however, an investigator who was blinded to the treatment group allocation determined the primary outcome, and the lack of placebo did not introduce bias related to the outcomes.

Intravaginal misoprostol was used in this study, rather than oral, rectal, buccal, or sublingual misoprostol.7 It is not clear from this study if the results of pretreatment with mifepristone would be different if misoprostol was administered via one of these other routes.


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