The incidence of heterosexual HIV transmission continues to increase, especially among women of childbearing age. This has obvious implications for the care of pregnant women and their children, which has become as much a social issue as a medical one. Progress in the development of assays for both HIV diagnosis and clinical evaluation has given us the tools with which to begin dealing with this epidemic. Problems intrinsic to neonatal diagnosis are currently being addressed. In the next few years, assays that achieve rapid diagnosis in infancy should be readily available at reasonable cost. The appropriate utilization of this technology is a matter of active debate.