A pregnant woman and the fetus she carries face health risks from many sources. One risk that requires ongoing vigilance is the use of prescription drugs during pregnancy. The international health care community has been sensitized to the risks of drug use during pregnancy because of three pharmaceuticals that have caused widespread crises for mothers and their offspring. The crises that diethylstilbestrol, thalidomide, and, to a lesser extent, Bendectin have created in the past four decades are reviewed in this article. The lessons these drug crises can teach us are articulated in the belief that similar crises may be averted in the future.