The aim of this study was to determine the maternal and umbilical cord serum ZDV levels at delivery in HIV-1 infected parturients treated with a short-course ZDV regimens in late pregnancy and labour. Serum ZDV and its metabolite were measured by high-performance liquid chromatography. Concentrations of ZDV and its metabolite in umbilical cord blood appeared similar to maternal concentrations. There was a significant positive correlation between serum ZDV and its metabolite in maternal and umbilical cord concentrations. At delivery, maintenance of optimal virustatic ZDV concentration with oral antenatal and oral intermittent intrapartum ZDV dosage regimen can be achieved in only 53% of cases. The regimens used in this study were useful but not as effective as the ACTG 076 regimen with an intravenous dose intrapartum plus the oral administration to the infants for 6 weeks.