Abstract
The pediatric HIV epidemic in the US and other more developed countries changed dramatically after February 1994, when the results of PACTG 076 demonstrated that a triple regimen of ZDV reduced the risk of perinatal transmission by nearly 70%. Incorporation of ZDV prophylaxis into clinical practice, together with increased prenatal HIV counseling and testing, rapidly resulted in a significant decline in perinatal transmission and a concomitant decrease in the number of reported pediatric AIDS cases in the US. Transmission rates of 3–6% have been reported in various cohort studies with ZDV prophylaxis alone, and of 1–2% when ZDV is combined with elective Cesarean delivery or when women are treated with highly active antiretroviral regimens that reduce maternal viral load to unquantifiable levels. Additionally, several short antiretroviral regimens, including those that require administration only during the intrapartum and early postpartum periods, have been shown to decrease perinatal transmission. These regimens provide effective intervention even for HIV-infected pregnant women who have not received antiretroviral therapy and are identified late in pregnancy or for the first time at delivery through rapid HIV testing.However, this success has been partially offset by increasing HIV infection rates among young women, high adolescent pregnancy rates among at-risk populations, continued failure to identify HIV infection during pregnancy and inadequate prenatal care among HIV-infected women, particularly those using drugs. Additionally, the impact of evolving patterns of antiretroviral drug resistance on efficacy of prophylaxis is not known. As combination antiretroviral therapy becomes the standard of care for pregnant women in developed countries, evaluation of their infants for short- or long-term adverse consequences of intrauterine antiretroviral exposure is also a priority. Finally, clinical trials have identified short-course antiretroviral prophylaxis regimens that are effective and safe in resource-poor countries; however, transmission of HIV via breast milk remains a concern.