• Maternal and infant response to prescribed interventions [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  
• Immune and viral parameters of participants taking prescribed interventions [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  

• Occurrences of genotypic and phenotypic resistance in HIV-infected mothers [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  
• Clinical, immunological, and virological responses in HIV-infected women [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  
• Mother-to-child transmission rates of resistance mutations [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  
• Adherence to ART among HIV-infected pregnant women during pregnancy and postpartum [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  

The current low rate of vertical transmission of HIV in the U.S. limits the number and types of questions concerning transmission risk and pathogenesis that can be addressed by a single clinical trial. Specific U.S. Public Health Service guidelines recommend antiretroviral therapy (ART) during pregnancy to maximize health of women. However, data regarding the effectiveness and safety of and adherence to ART during pregnancy are limited. It is both appropriate and necessary for the IMPAACT to recruit pregnant women into a non-interventional, analytic, epidemiologic study to methodically collect clinical and laboratory data from them and their infants. This way, the IMPAACT can achieve the aims of evaluating management of HIV-infected women during pregnancy and determining the safety and effectiveness of ART and other interventions intended to prevent vertical transmission and/or improve maternal health. In addition, longitudinally collected core protocol data and repository specimens will enable future substudies.

Participants receive no protocol specific treatment or other intervention as part of this study. The study involves the follow-up of HIV-infected women enrolled during pregnancy or at the time of delivery for 6 months postpartum and their infants for the first 6 months of life. There will be 8 study visits for enrolled participants and 6 study visits for infants. Data concerning ART use, adherence to medications, and review of symptoms relevant to side effects and toxicities are collected through administration of questionnaires at all maternal visits. Phlebotomy is conducted to obtain specimens for a repository and for required laboratory tests. During labor and delivery, maternal blood is obtained for lymphocyte subset and viral load assays and for repository storage. Collection of amniotic fluid at the time of cesarean section is encouraged. These collections are submitted to a central repository. Data for the core protocol are abstracted from the infant's medical record at the time of birth and at each postnatal visit.

Primary care clinics

Inclusion Criteria:

• HIV infected
• At least 14 weeks pregnant OR have delivered a liveborn or stillborn infant and are within 14 days of the delivery
• Currently receiving care at an IMPAACT or other participating site
• Have a parent or guardian willing to provide signed informed consent, if applicable
• Mentally capable of giving informed consent to have the infant and self followed at an IMPAACT site

Exclusion Criteria:

• Intend to end the pregnancy
• Unable to come for a study visit within 14 days after delivery (if known to be HIV infected prior to delivery) OR within 28 days after delivery (if found to be HIV infected at the time of labor and delivery or within 14 days after delivery)