Gene therapy may provide a new therapeutic approach to pediatric AIDS. Putting an HIV-resistant gene into umbilical cord blood stem cells and transplanting the cells back into the patient could lead to the production of cells that resist HIV infection. If a patient's cells could be engineered to be resistant to supporting the growth of HIV-1, the cells may have improved survival in the presence of HIV-1. To date, an umbilical cord blood bank for HIV-positive deliveries has not been established in the United States. This protocol establishes a repository of banked umbilical cord blood as a first step toward the potential application of gene therapy for the treatment of HIV-infected infants.