Abortion with mifepristone and misoprostol: regimens, efficacy, acceptability and future directions.

Mifepristone at a dose of 600 mg followed by 400 microg misoprostol orally has been used for early abortion by hundreds of thousands of women with success rates at </=49 days' gestation ranging from 92% to 97%. Newer regimens may prove simpler than this standard regimen and may serve a larger number of patients. Vaginal rather than oral administration of misoprostol may have advantages, including improvement in the efficacy of mifepristone regimens at >49 days' gestation. A lower mifepristone dose of 200 mg and in-home self-administration of misoprostol both appear safe and effective. Although most research protocols have used ultrasonography to confirm gestational age, the method can be provided safely without routine reliance on ultrasonography. Acceptability of the method to care providers and to patients has been high in all studies. The introduction of medical abortion into general medical practice in the United States will teach us much about the practical aspects of service provision.