Short‐term efficacy and safety of early medical abortion in Japan: A multicenter prospective study

PURPOSE: To evaluate the short‐term efficacy and safety of a combined mifepristone‐misoprostol regimen in individuals seeking medical abortion at up to 63 days of gestational age. METHODS: This open‐label, multicenter, prospective study evaluated the short‐term efficacy and safety of medical abortion, with the primary outcome being the abortion success rate 24 h after misoprostol administration. The participants received 200 mg of mifepristone orally and 800 μg of misoprostol buccally in the hospital/clinic 36–48 h later. Bleeding and lower abdominal pain, which are the main symptoms associated with medical abortion, were recorded. RESULTS: The abortion success rate was 93.3% (95% confidence interval [CI]: 87.3–97.1%) within 24 h of misoprostol administration, 63.3% (95% CI: 54.05–71.94%) within 4 h, and 90.0% (95% CI: 83.18–94.73%) within 8 h. The median time from misoprostol administration to a successful abortion was 3.93 h. Bleeding was most commonly observed 0–4 h prior to the confirmation of gestational sac (GS) expulsion. The most intense lower abdominal pain occurred 0–1 h before the confirmation of GS expulsion. CONCLUSION: The combined regimen of mifepristone and buccal misoprostol for medical abortion showed short‐term efficacy and a favorable safety profile.