Early Pregnancy Termination with Mifepristone and Misoprostol: Concurrent vs. 48-Hour Interval Administration in a Randomized Controlled Trial

TL;DR

A study found that taking mifepristone and misoprostol together for early pregnancy termination is less effective and less satisfying than taking them 48 hours apart.

Contribution

This study provides evidence comparing concurrent versus interval administration of abortion medications, showing lower efficacy for the concurrent method.

Findings

Concurrent administration had a lower success rate (68.8%) compared to the 48-hour interval regimen (84.3%).

Concurrent treatment was associated with higher rates of continuing pregnancy (13.4% vs. 2.8%).

Patient satisfaction was higher in the 48-hour interval group compared to the concurrent group.

Abstract

Background: The standard protocol for early first-trimester termination of pregnancy (TOP) involves administration of mifepristone followed by misoprostol after a 48-h interval. While concurrent administration may improve convenience and access, evidence regarding its effectiveness remains limited. This study aims to compare the efficacy, safety, and acceptability of concurrent oral administration of mifepristone and misoprostol with the 48-h interval regimen for early TOP. Methods: In this randomized controlled trial (ClinicalTrials.gov: NCT03440866), 250 patients with intrauterine pregnancies up to 49 days’ gestation were randomized to receive either concurrent treatment (600 mg mifepristone and 400 mcg misoprostol) or the same medications administered 48 h apart. The primary outcome was complete abortion without additional intervention. Secondary outcomes included adverse events, pain, and patient satisfaction. Follow-up occurred approximately two weeks post-treatment. Data were available for 220 participants. Results: The concurrent group had a significantly lower success rate compared to the control group (68.8% vs. 84.3%, p = 0.007). Continuing pregnancy was more frequent with concurrent administration (13.4% vs. 2.8%, p = 0.004). No significant differences were observed in hemoglobin change, adverse events, or pain scores. Patient satisfaction was higher in the control group (81.1% vs. 63.6%, p = 0.04), though preferences for future abortion methods did not differ between groups. Conclusions: Concurrent administration of mifepristone and misoprostol is less effective and less satisfactory than the standard 48-h regimen, although safety and pain profiles are comparable. It should not replace the interval protocol, and patients choosing concurrent treatment should be counseled about its lower efficacy and higher likelihood of requiring additional intervention.

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