Perinatal HIV and Its Prevention: Progress Toward an HIV-free Generation

Abstract

Since the first cases of infant HIV infection were described in the early 1980s, significant progress has been made in our understanding of risk factors for mother-to-child transmission (MTCT) of HIV as well as effective interventions to prevent transmission. MTCT of the human immunodeficiency virus type-1 (HIV-1) can occur during pregnancy particularly in the third trimester, during the intrapartum period, and for infants exposed to HIV, who are breastfed, throughout the period of lactation.1 Before the availability of antiretroviral and obstetric interventions, about 1 in 4 infants born to women infected with HIV became infected. Among these infected infants, 50% to 60% of transmission occurred around the time of labor or delivery based on newborn infants exposed to HIV having negative cord blood or newborn polymerase chain reaction (PCR) tests that subsequently became positive within the first weeks of life.2 Among HIV-infected breastfeeding populations, about 20% to 25% of infections occurred in utero based on positive PCRs at birth; 35% to 50% intrapartum; and another 25% to 35% of infants negative at birth and in the first 6 weeks became infected later, presumably as a result of transmission through breast milk.