OF PERINATAL HIV TRANSMISSION? AMANDA COTTER, LUNTHITA DUTHELY, VICTOR HUGO GONZALEZ QUINTERO, MARY JO O’SULLIVAN, University of Miami, Obstetrics and Gynecology, Miami, Florida, University of Miami, OB/GYN Research, Miami, Florida, University of Miami, Dept of Ob/ Gyn-MFM Division, Miami, Florida OBJECTIVE: To determine the optimal antiretroviral (ART) regimen for the prevention of perinatal transmission (PNT) of HIV in women who do not require ART for their own health. STUDY DESIGN: Using prospectively gathered data from our perinatal database, women diagnosed HIV positive prior to or during pregnancy with care at our prenatal clinic from 1999-2004 were identified. Inclusion criteria were women requiring ART only for prevention of PNT and neonatal HIV status. Women were categorized according to ART use in pregnancy: Trizivir, Combivir/Nevirapine (NVP), Combivir/Nelfinavir (NFV). RESULTS: The cohort comprised 634 deliveries of whom 155 women required ART only for prevention of PNT: Trizivir n = 61, Combivir/NVP n = 88, Combivir/NFV n = 6. A VL!1000 at delivery was achieved by 82% on Trizivir, 76% on Combivir/NVP and 83% on Combivir/NFV. The mean duration of therapy was 15.9, 15.3 and 20.9 weeks for Trizivir, Combivir/NVP and Combivir/NFV respectively.There was one case of hepatotoxicity associated each with Combivir/NVP and Combivir/NFV. All infants were liveborn except for 2 stillbirths and 2 spontaneous abortions in the Combivir/NVP group. There was only one case of PNT and this was in a woman on Trizivir. CONCLUSION: Although rarely utilized outside of pregnancy, Trizivir is an ideal ART regimen associated with similar pregnancy outcomes to other popular regimens without a significant risk of toxicity or adherence issues while reserving other ART regimens for later when required for maternal health.