Pregnant women who are HIV-positive are at risk of giving HIV to their babies during pregnancy or delivery. It is important to learn how to prevent HIV-positive pregnant women from giving HIV to their babies. RTV and ZDV have been shown to be safe and effective against HIV in adults. The combination of 3 anti-HIV drugs (RTV, 3TC, and ZDV) may help prevent HIV infection from mother to infant but studies are needed to determine whether they are safe and effective during pregnancy.