In the United States, current human immunodeficiency virus (HIV) testing guidelines recommend an opt-out approach for pregnant women, whereby HIV testing is incorporated routinely into the standard panel of prenatal tests with the option to decline. Current recommendations for the initiation of treatment of HIV infection in pregnant women are the same as those for nonpregnant women. However, the special circumstances of pregnancy raise additional issues that are related to potential drug toxicity to the mother and fetus, which affect the choice of antiretroviral drugs to be used. For HIV-infected pregnant women who do not require therapy for their own health, antiretroviral drugs are recommended for prevention of mother-to-child transmission. Highly active antiretroviral therapy is recommended for all women with HIV RNA levels of > or = 1000 copies/mL, along with consideration of elective cesarean delivery. For women with HIV RNA levels of < 1000 copies/mL, a 3-part zidovudine prophylaxis regimen (prenatal, intrapartum, and neonatal) should be used alone or in combination with other antiretroviral drugs.