Short-course therapy with zidovudine plus lamivudine for prevention of mother-to-child transmission of human immunodeficiency virus type 1 in Thailand.

To evaluate the efficacy and safety of short-course therapy with zidovudine plus lamivudine for reduction of perinatal transmission of human immunodeficiency virus type 1 (HIV-1), a single-arm, open-label, prospective, nonrandomized study was conducted. One hundred six treatment-naive pregnant women received zidovudine (300 mg) plus lamivudine (150 mg) twice daily from week 34 of gestation until the onset of labor. During labor, zidovudine and lamivudine were given every 3 h. Neonates received zidovudine syrup for 4 weeks and were bottle fed. The median maternal virus load and CD4+ cell count at weeks 32-34 of gestation were 4.33 log10 copies/mL and 274 cells/mm3, respectively. At delivery, the mothers' mean decrease in virus load was 1.55 log10 copies/mL and the mean increase in CD4+ cell count was 93 cells/mm3, compared with enrollment levels. Three neonates were HIV-1 infected, for a transmission rate of 2.83% (95% confidence interval, 1%-8%). There were no serious adverse events in the mothers. Adverse events noted in neonates were anemia (in 6 neonates), elevated transaminase levels (in 1), and thrombocytopenia (in 3). Short-course therapy with zidovudine plus lamivudine appeared to be safe and effective for prevention of perinatal transmission of HIV-1.