The Maternal and Pediatric Infectious Disease Branch (MPIDB) promotes research to investigate the impact and treatment of HIV, its complications, and other significant infectious diseases in infants, children, adolescents, and pregnant and nonpregnant women. This includes contracted clinical research activities conducted primarily in two major networks that actively collect specimens to be housed in the NICHD repository. These are the Pediatric HIV AIDS Cohort Study (PHACS) and the International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT) network. PHACS is a multicenter United States-based program that follows both perinatally HIV-infected youth and HIV-exposed/uninfected infants, children, and youth. PHACS currently includes four main protocols and four sub studies. A wide variety of specimen types are collected at 18 SMARTT (Surveillance Monitoring for ART Toxicities Study in HIV-uninfected Children Born to HIV-infected Women) and 14 AMP (Adolescent Master Protocol) current study sites that require repository services. The IMPAACT Network is focused on evaluating potential therapies for HIV infection and its related symptoms in infants, children, adolescents, and pregnant women, including clinical trials of HIV/AIDS interventions for prevention of mother-to-child transmission. The research agenda includes studies on the pharmacokinetics, safety, optimal dosing, and long-term complications of new antiretroviral (ARV) therapies for HIV/AIDS in pediatric and adolescent populations and in pregnant women. NICHD-funded sites (via the NICHD International and Domestic Pediatric and Maternal HIV Studies and Other Infectious Diseases Data Coordinating Center contract) utilize the NICHD repository; NIAID-funded sites utilize a separate NIAID-supported repository. NICHD-supported sites also perform other trials independently or within other networks. The IMPAACT network collects samples in specific protocols at 14 U.S. and 9 international NICHD clinical research sites. A wide variety of specimen types are collected and require repository services. The Data and Operations Center for both PHACS and IMPAACT is at the Harvard School of Public Health with data management services provided by Frontier Science Technology Research Foundation (FSTRF). Both PHACS and IMPAACT use the Frontier Science LDMS laboratory information management system to manage their sample collections. The IMPAACT Network collaborates with the NICHD Domestic & International Pediatric & Maternal HIV & Other High-Priority Infectious Diseases Clinical Studies Network, the Adolescent Medicine Trials Network for HIV/AIDS Interventions, and with other NICHD-, NIH-, and organization-led HIV/AIDS research networks and projects.