Vertical transmission of HIV from mother to child may occur before, during, or after parturition (via breast-feeding). It is believed that therapy administered both during pregnancy and intrapartum may help prevent vertical transmission. Additionally, adjunctive short-term antiretroviral therapy for the newborn, following the intensive viral exposure presumed to occur at birth, may be necessary.

Pregnant women who are currently receiving AZT are randomized at 20-30 weeks of gestation to begin receiving either HIVIG or IVIG every 28 days up to delivery. Within 12 hours after birth, the infant receives an infusion of matching study drug. During labor, all women receive an intravenous loading dose of AZT administered over 1 hour, followed by continuous infusion during the intrapartum period until the umbilical cord is clamped. All infants receive AZT syrup every 6 hours, beginning as soon as oral fluids are tolerated but within 8-12 hours after birth and continuing for 6 weeks. Women are followed until 26 weeks postpartum. Infants are followed at weeks 1, 2, 4, and then every 4 weeks through week 24, every 12 weeks through week 60, at week 78 (18 months), and at week 104 (24 months).

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).