The purpose of this study was to evaluate the effect of elective cesarean delivery plus a lamivudine-zidovudine prophylaxis regimen on non-breastfeeding mothers with human immunodeficiency virus type 1 and their infants.

Forty-six antiretroviral-naı̈ve, pregnant women with human immunodeficiency virus type 1 were included. The prophylactic regimen was a lamivudine-zidovudine tablet (150 mg/300 mg) twice daily from week 34 of pregnancy until cesarean delivery at week 38 of gestation, preoperative intravenous zidovudine, and neonatal zidovudine syrup for 4 weeks.

At weeks 34 and 38 of gestation, the median maternal viral loads were, respectively, 3.65 log₁₀ copies/mL (range, 2.34-4.70 log₁₀ copies/mL) and 2.51 log₁₀ copies/mL (range, 2.04-3.66 log₁₀ copies/mL; P<.001), respectively; the viral reduction was 1.12 log₁₀ copies/mL (range, −0.16-2.60 log₁₀ copies/mL), and the CD4⁺ cell counts increased from 335 cells/mm³ (range, 57-974 cells/mm³) to 420 cells/mm³ (range, 84-1,083 cells/mm³; P=.002). No mother or infant had a serious adverse event. Two infants were infected (4.3%; 95% CI, 0 .5%-15.7%); 1 infant had intrapartum infection.

Elective cesarean delivery plus short-course lamivudine-zidovudine is safe but does not eliminate mother-to-child transmission of human immunodeficiency virus type 1.