Randomized trial of oral versus vaginal misoprostol at one day after mifepristone for early medical abortion

Mifepristone was recently approved in the United States. Regimens with shor ter intervals may be more acceptable. The objective of this study was to de termine whether the oral route of misoprostol was as effective as the vagin al route of misoprostol 1 day after mifepristone. A prospective, open-label ed, randomized trial of healthy adult women up to 63 days pregnant and want ing a medical abortion were randomized to use either two doses of oral miso prostol 400 mug taken 2 h apart or misoprostol 800 mug vaginally. Women sel f-administered misoprostol 1 day after taking one-third of the standard dos e of mifepristone (200 mg) orally. Women then returned to the clinic up to 5 days later for a repeat sonogram evaluation. A dose of vaginal misoprosto l was administered to women with a continuing pregnancy who then returned 1 day later to Day 15. The primary outcome measures were a complete medical abortion by the first or by the second follow-up visits. Surgical intervent ion was indicated for continuing pregnancy at the second follow-up visit, e xcessive bleeding, or persistent products of conception 5 weeks later. One thousand one hundred sixty-eight women were enrolled. Of the 1144 (98%) wom en who complied with their random assignment, two oral doses of misoprostol (800 mug total) were 90% effective at inducing an abortion by the first fo llow-up visit, compared with one dose of misoprostol by vagina of 97% (chi (2) = 23.95, p = 0.001). By the second follow-up visit, the complete aborti on rate was 95% for oral misoprostol and 99% for vaginal misoprostol (chi ( 2) = 21.76, p = 0.001). There were minimal differences in side effects. Wom en preferred the oral route. The trial demonstrated that although two doses of oral misoprostol were effective, the vaginal misoprostol was snore effe ctive at inducing an early medical abortion at 1 day after low-dose mifepri stone, and the regimen could be extended to 63 days gestation. (C) 2001 Els evier Science Inc. All rights reserved.