A Phase III Randomized, Double-Blind, Controlled Study of the Use of Anti-HIV Immune Serum Globulin (HIVIG) for the Prevention of Maternal-Fetal HIV Transmission in Pregnant Women and Newborns Receiving Zidovudine (AZT)

Inclusion Criteria Concurrent Medication: Allowed: * Women - Medications as required for obstetrical management of HIV infection (e.g., acyclovir, ketoconazole, isoniazid, antibiotics, or other antiretroviral therapy if intolerant or failing on AZT), unless specifically excluded. * Infants - Drug treatment for signs of drug withdrawal (phenobarbital, chlorpromazine, tincture of opium, paregoric or Valium). * Infants - Medications as indicated for management of an HIV-exposed infant (e.g., hepatitis B vaccine, syphilis treatment, Pneumocystis carinii pneumonia prophylaxis). Patients must have: * Documented HIV infection. * Been receiving AZT during current pregnancy for medical indications. * Gestational age between 20 and 30 weeks. * Intention to carry pregnancy to term. * Available venous access (placement of central line or Hickman catheter not indicated for study purposes). * Willingness to be followed by a participating site for study duration. NOTE: * Father of fetus (if available after a reasonable attempt to contact him) must also provide informed consent. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Illness associated with excessive protein loss, e.g., severe proteinuria (protein \>= 4 g protein in a 24-hour urine collection). Patients with the following prior conditions are excluded: * Evidence of pre-existing fetal anomalies (e.g., anencephaly, renal agenesis, or Potter's syndrome) that may result in a high probability that the fetus-infant would not survive to the end of the study period. * Chorionic villus sampling (CVS) or percutaneous umbilical blood sampling (PUBS) occurring in this pregnancy prior to study entry. * Illness associated with excessive protein loss, e.g., chronic diarrhea with no documented weight gain in a 3-month period during pregnancy. * Pre-existing conditions such as hypogammaglobulinemia or immune thrombocytopenia that are felt to require IVIG therapy. Prior Medication: Excluded: * Receipt of anti-HIV vaccines or passive immunotherapy with HIVIG or IVIG during this pregnancy prior to study entry. * Receipt of antiretroviral agents other than AZT during this pregnancy prior to study entry (e.g., rCD4, CD4-IgG, d4T, ddC, ddI).