A Prospective, Observational Study of HIV-Infected Pregnant Women and Their Infants at Clinical Sites in Latin American and Caribbean Countries

* INCLUSION CRITERIA: (HIV-Infected Pregnant Women) Pregnant women at 22 weeks of gestation or more with documentation of pregnancy, using one or more of the following: Urine HCG pregnancy test; Serum HCG pregnancy test; Positive fetal heart tones by Doppler; or Ultrasound. Documentation of HIV infection, defined by any two of the following prior to or during pregnancy: Reactive test for HIV antibody; Positive HIV culture; Positive HIV DNA PCR; Positive neutralizable HIV p24 antigen; Positive qualitative HIV RNA; Quantitative HIV RNA greater than or equal to 1000 copies/ml; and Diagnosis of AIDS-defining clinical condition. Willingness and intent to deliver at the participating clinical site and to be followed through six months postpartum at the site or associated outpatient facility. Willingness and ability to sign informed consent-Subject must be of an age to provide legal informed consent as defined by the country in which the subject resides. Willingness and intent to have children followed for up to 5 years. Subjects may be co-enrolled in clinical trials for treatment or prophylaxis of HIV infection, opportunistic infections, or other HIV related problems. Subjects may be re-enrolled with subsequent pregnancies during this study. However, if so, their follow-up for the previous pregnancy will be discontinued. Children from each pregnancy will be followed in accordance with the protocol. Subjects may enroll up to and prior to delivery, including during labor. INCLUSION CRITERIA: (Dynamic Pediatric Cohort) -HIV-exposed children born to enrolled HIV-infected pregnant women. Children diagnosed with HIV infection will be discontinued from the present protocol and(if eligible) offered enrollment into a concurrent NICHD-funded protocol for HIV-infected children. INCLUSION CRITERIA: (Static Pediatric Cohort) -HIV-exposed, uninfected children who are 6 months of age through 5 years 364 days of age and were previously enrolled in the NISDI Pediatric Protocol or NISDI Perinatal Protocol. And * Other HIV-exposed, uninfected children who are 6 months of age through 5 years 364 days of age at time of enrollment into this protocol. 1. Documentation of HIV-uninfected status should be obtained from medical record review. 2. Evidence of the HIV-uninfected status of the infants and children can be documented by the following: --Two or more negative HIV virologic assays (e.g., HIV culture or HIV DNA PCR) with one test performed at age 1 month or older and one performed at age 4 months or older, and no positive virologic tests. Or --One or more negative HIV virologic assays performed at 1 month of age or older with one or more negative HIV antibody tests (including HIV rapid tests) performed at greater than or equal to 6 months of age. Or --One positive HIV virologic assay, with at least two later negative HIV virologic tests (at least one of which is after age 4 months of age) or negative HIV antibody tests (at least one of which is after 6 months of age). 3. Documentation of HIV infection in the mother must have been obtained either prior to or during pregnancy or within one month postpartum. 4. Evidence of HIV infection in the mother can be documented by two or more of the following: * Reactive test for HIV antibody; * Positive HIV culture; * Positive HIV DNA PCR; * Positive quantitative HIV p24 antigen above assay cutoff; * Positive qualitative HIV RNA; * Quantitative HIV RNA \>= 1000 copies/ml; and * Diagnosis of AIDS-defining clinical condition. 5. Complete data regarding maternal medications received during pregnancy must be available through medical record abstraction. EXCLUSION CRITERIA: (HIV-Infected Pregnant Women) Failure to meet inclusion criteria. EXCLUSION CRITERIA: (Dynamic Pediatric Cohort) * Failure to meet inclusion criteria EXCLUSION CRITERIA: (Static Pediatric Cohort) * HIV infection of the child * Insufficient documentation of HIV infection in the mother obtained either prior to or during pregnancy or within one month postpartum. * Insufficient evidence of HIV infection in the mother * Insufficient perinatal data 1. Incomplete data regarding maternal medications received during pregnancy (e.g., missing start and stop dates). 2. Incomplete data regarding postnatal ARV exposure.