Antiretroviral Therapy Use During Pregnancy and the Risk of Small for Gestational Age Birth in a Medicaid Population.

BACKGROUND: Several studies have assessed the association between antiretroviral (ARV) therapy use during pregnancy and small for gestational age (SGA), but the evidence remains incompletely elucidated. METHODS: We linked data from Tennessee Medicaid files and vital records to evaluate pregnancies among human immunodeficiency virus (HIV)-infected women who delivered between 1994 and 2009. Maternal HIV status was defined based on diagnosis codes, ARV prescriptions and laboratory codes for CD4 count or HIV RNA assays. ARV use was identified from pharmacy claims. Risk of SGA (defined as birth weight below the 10th percentile for gestational age) and preterm birth was evaluated using logistic regression models. RESULTS: Four hundred and seventy-seven HIV-infected pregnant women contributing 604 singleton pregnancies were identified; 156 (26%) delivered SGA infants. ARV use during pregnancy was not associated with SGA [adjusted odds ratio: 0.93; 95% confidence interval (CI): 0.56-1.56] or preterm birth (adjusted odds ratio: 0.74; 95% CI: 0.42-1.32). Exposure to a protease inhibitor during the first trimester was associated with a lower risk of SGA (odds ratio: 0.54; 95% CI: 0.29-1.01) compared with non-exposure to a protease inhibitor throughout pregnancy. CONCLUSIONS: We observed no evidence of an association between ARV exposure during pregnancy and SGA delivery in this Medicaid cohort of HIV-infected women.