Fortovase (Saquinavir) Given With Low-Dose Ritonavir, Zidovudine, and Lamivudine to HIV-Positive Pregnant Women During and After Pregnancy and to Their Newborns

Inclusion Criteria Patients may be eligible for this study if they: * Are HIV-positive. * Are 14 to 32 weeks pregnant. * Are at least 13 years old (need consent of parent or guardian if under 18). Exclusion Criteria Patients may not be eligible for this study if they: * Cannot take ZDV, 3TC, or higher doses of RTV. Women who are able to tolerate low doses of RTV may be eligible. * Are pregnant with more than 1 baby. (This study has been changed so that a patient pregnant with more than 1 baby is not eligible.) * Have pregnancy complications or have medical problems that put pregnancy at risk. * Have an active opportunistic (HIV-related) infection and/or serious bacterial infection at study entry. * Have chronic diarrhea. * Abuse alcohol or drugs. * Do not have access to a participating clinic or are not willing to be followed at the same clinic for the duration of the study. * Have received certain antiretroviral (anti-HIV) drugs or are taking certain medications. (This study has been changed to increase enrollment. The eligibility criterion in earlier versions was more restrictive, and has been changed to include women receiving SQV \[with or without RTV\], 3TC, and ZDV for longer than 3 weeks if their pre-entry viral load is 400 copies/ml or less OR if they have a significant reduction in viral load within 90 days of the pre-entry visit.) * Plan to breast-feed.