his review summarizes recent advances in the prevention of HIV-1 transmission from mother to child. In the United States and many other resource-rich countries, remarkable progress has been made since 1994 toward eliminating vertical HIV-1 transmission. Nevertheless, critical research questions as well as public health challenges remain. The U.S. Centers for Disease Control and Prevention (CDC) estimates that 280 to 370 HIV-infected infants were born in the United States each year between 1999 and 2001. New infant infections continue to occur primarily among women who did not obtain prenatal care or who were not offered HIV testing during pregnancy; innovative approaches are needed to address these barriers. Primary HIV infection in the mother during the perinatal period also contributes to infant infections. Without any intervention, the risk of mother-to-child HIV-1 transmission ranges from about 15% to 40%, with the highest rates reported in breastfeeding populations. Internationally, new clinical trial findings provide hope that a short course of treatment with antiretroviral drugs can substantially reduce vertical HIV-1 transmission in resource-poor settings in the developing world, where > 98% of all pediatric HIV infections occur. New research studies are focusing on the role of postperinatal exposure prophylaxis with antiretroviral drugs administered to the infant and/or the mother followed by early weaning and on the prevention of postnatal transmission of HIV-1 through breast milk while maintaining adequate nutrition. An urgent task now is to translate promising trial results into an effective global public health response, guided by local input and the will to maximally reduce pediatric HIV infections worldwide.
