Vaginal misoprostol administered 1, 2, or 3 days after mifepristone for early medical abortion: A randomized trial

Abstract

Context: The conventional timing of misoprostol administration after mifepristone for medical abortion is 2 days, but more flexible intervals, which may make the regimen more convenient, have not been studied.

Objective: To determine whether vaginal misoprostol administered 1, 2, or 3 days after mifepristone influences safety or effectiveness for abortion at up to 56 days' gestation.

Design: Prospective, randomized, open-label trial conducted from March 1998 to June 1999.

Setting: Sixteen US primary care and referral abortion facilities.

Patients: A total of 2295 healthy patients aged 18 years or older who were 56 or fewer days pregnant. Forty (1.7%) were lost to follow-up.

Interventions: Patients received 200 mg of oral mifepristone and were randomly assigned to self-administer 800 microg of vaginal misoprostol at home 1 (n = 745), 2 (n = 778), or 3 (n = 772) days later. Women returned to the clinic up to 8 days after mifepristone for ultrasonographic evaluation. A second dose of misoprostol was administered if the abortion was not complete. Patients with continuing pregnancy, excessive bleeding, or retained pregnancy tissue 5 weeks later received an aspiration curettage.

Main outcome measures: Effectiveness of the procedure (ie, a complete medical abortion without surgical intervention), adverse effects, acceptability of the procedure based on patient questionnaires, reasons for surgical intervention, and adverse outcomes, compared among the study groups.

Results: Of the 2255 women completing follow-up, complete medical abortion rates were 98% (95% confidence interval [CI], 97%-99%) among those using misoprostol after 1 day, 98% (95% CI, 97%-99%) for those using misoprostol after 2 days, and 96% (95% CI, 95%-97%) among those using misoprostol after 3 days. Fifty-five subjects aborted before taking misoprostol, 9 had early surgery, and 103 did not take misoprostol on their assigned day. No blood transfusions were required. Cramping and nausea were the most common adverse effects reported, with similar percentages of patients in all 3 groups reporting such effects. Thirteen unexpected or serious adverse events occurred: 6 in those using misoprostol after 1 day; 4 in those using it after 2 days; and 3 in those using it after 3 days. Nearly all women (>90%) found the procedure to be acceptable.

Conclusions: Our results suggest that vaginal misoprostol, 800 microg, can be used from 1 to 3 days after mifepristone, 200 mg, for early medical abortion, and need not be administered strictly 48 hours after mifepristone. JAMA. 2000;284:1948-1953.