Birth defects among a cohort of infants born to HIV-infected women on antiretroviral medication

Objective: To determine rate of and risk factors for birth defects in infants born to HIV-infected women receiving nucleoside and protease inhibitor antiretroviral (ARV) therapy. Methods: Birth defects were evaluated among infants on the Pediatric AIDS Clinical Trials Group 316 trial that studied addition of peripartum nevirapine to established ARV regimen for prevention of mother-to-child transmission. Maternal therapy was categorized by trimester of earliest exposure. Birth defects were coded using conventions of the Antiretroviral Pregnancy Registry. Results: Birth defects were detected in 60/1414 (4.2%; 95% CI 3.3-5.4%) infants including 30/636 (4.7%; 95% CI 3.2-6.7%) with first trimester ARV exposure and 30/778 (3.9%; 95% CI 2.6-5.5%) with exposure only after the first trimester (P=0.51). Rates of classes of defects were similar between first trimester compared to later exposure groups except heart defects which occurred in 16 (2.5%; 95% CI 1.4-4.1%) with first trimester ARV exposure and in six (0.8%; 95% CI 0.3-1.7%) infants with later exposure (P=0.02). Exposure to ARV was not associated with specific types of heart defects. Two cases of cardiomyopathy were noted. Conclusion: ARV use in early pregnancy was not associated with an increased risk of birth defects overall. The possible association of ARV exposure with heart defects requires further surveillance.