Objective: To estimate the efficacy and acceptability of medical abortion at 64-70 days from last menstrual period (LMP) and to compare it with the already proven 57-63 days from LMP gestational age range.
Methods: This prospective, comparative, open-label trial enrolled 729 women with pregnancies 57-70 days from LMP requesting abortion at six U.S. clinics. Medical abortions were managed with 200 mg mifepristone and 800 micrograms buccal misoprostol and sites' service delivery protocols. Follow-up visits occurred 7-14 days after mifepristone, with an abortion considered complete if surgical intervention was not performed. Success, ongoing pregnancy, and acceptability rates were compared.
Results: A total of 629 cases were analyzable for efficacy. Success rates were similar in the two groups (57-63 days group: 93.5%, 95% confidence interval [CI] 90-96; 64-70 days group: 92.8%, 95% CI 89-95). Ongoing pregnancy rates also did not differ significantly (57-63 days: 3.1%, 95% CI 1.6-5.8; 64-70 days: 3.0%, 95% CI 1.5-5.7). Acceptability was high and similar in both arms, with most women (57-63 days: 87.4%; 64-70 days: 88.3%) reporting that their experience was either very satisfactory or satisfactory.
Conclusion: Medical abortion with mifepristone and misoprostol in current outpatient settings is an efficacious and acceptable method of ending pregnancies 64-70 days from LMP and can be offered without alteration of existing services.
Clinical trial registration: clinicaltrials.gov, www.clinicaltrials.gov, NCT00997347.
Level of evidence: II.