ObjectiveTo review the literature on medical abortion in early pregnancy.Data SourcesI performed a MEDLINE search, supplemented by bibliographies of articles and textbooks. In addition, investigators in the field were consulted to identify other sources. The review was limited to reports in English or French concerning antiprogestins or methotrexate used either alone or in combination with a prostaglandin.Methods of Study SelectionOnly those mifepristone studies with 100 or more participants were included. Those participants who received the prostaglandin sulprostone were excluded because this drug is no longer used with mifepristone. Methotrexate studies of any size were included. All reports were categorized by study type, and the evidence was evaluated using the U.S. Preventive Services Task Force rating system.Tabulation, Integration, and ResultsBoth mifepristone and methotrexate, when used with a prostaglandin, can induce abortion safely in early pregnancy. Class I evidence supports a class A (good) recommendation that oral, single mifepristone doses of 200 mg and 600 mg have similar efficacy when used with a prostaglandin. Sequential and single-dose regimens have comparable efficacy. Vaginal misoprostol at 800 μg as an augmenting agent appears superior to the same dose given orally. With methotrexate abortion, 800 μg of misoprostol given vaginally 7 days after methotrexate is superior to the same dose given 3 days after. In addition, methotrexate in combination with misoprostol is more effective than misoprostol alone.ConclusionMedical abortion with mifepristone or methotrexate in combination with a prostaglandin is safe and effective. However, the risk of hemorrhage and gastrointestinal side effects is greater with medical abortion than with suction curettage. Further research should be done to compare mifepristone and methotrexate abortions, to determine the upper gestational age limit, and to find the best way to provide this service in the U.S. health care system.