 We are conducting a clinical trial of tenofovir TDF and emtricitabine FTC, marketed as a fixed dose combination, Truvada TM, to reduce NNRTI-resistance post-delivery in the setting of NVP with or without ZDV for PMTCT. TDF and FTC are both Category B drugs and are approved for use in pregnancy. They have several characteristics that make them ideal candidate drugs for use in conjunction with NVP, including long intracellular half-lives and established safety profile among adults for HIV treatment. 