The increasing seroprevalence of human immunodeficiency viruis (HIV) among women of reproductive age and the risks of vertical transmission of HIV have led to recommendations for routine prenatal HIV counseling and testing. The incentive to undergo such testing is related not only to fetal concerns, but also to the potential benefit of early and comprehensive therapy for women. Treatments that should be considered for use during pregnancy include the antiretroviral agent zidovudine and prophylactic agents to prevent Pneumocystis carinii pneumonia, the most common opportunistic infection seen in patients progressing to AIDS. Assessment of the risks and benefits of these treatments during pregnancy is complex and requires discussions between physician and patient. This paper reviews current information and provides recommendations for incorporating therapies into obstetric practice.