Update: preventing mother-to-child transmission of HIV.

The success of antiretroviral therapies for prevention of mother-to-child transmission of HIV in the developed world has prompted a wide array of research efforts, from improved implementation of voluntary counseling and testing programs to innovative approaches for short-course peripartum prophylaxis to understanding the dynamics of HIV transmission via breastfeeding. Clinical trials of modified short-course peripartum regimens which are applicable to resource-limited areas are demonstrating much lower transmission rates and preliminary data are emerging on limiting transmission via breastfeeding. Some of the most recent data on these topics are reviewed. Primary prevention of HIV in women of childbearing age combined with efforts to prevent mother-to-child transmission of HIV offer the best hope for addressing the burden of HIV in women and children.