In 2000, the F.D.A. approved the combination of mifepristone, a steroid that breaks down the lining of the uterus, and misoprostol, a prostaglandin that induces contractions. The agency did so based on clinical trials involving a large dose of mifepristone in the clinic, a dose of misoprostol in the clinic two days later, then a third clinic visit on the 14th day to verify that the fetus had aborted. The procedure was recommended for use through seven weeks of pregnancy. Since then, studies have shown that mifepristone works as well at one-third the previously used dose, that it is safe to take the second medication at home, and that the procedure is safe and effective through the ninth week of pregnancy, according to the National Abortion Federation, the World Health Organization and other medical groups. - www.nytimes.com