Prenatal zidovudine use and congenital anomalies in a Medicaid population

Objectives: To examine the association of prescribed zidovudine (ZDV) durin g pregnancy with congenital anomalies in a population-based cohort. Methods: Medicaid claims were used to assess prescribed ZDV and children's major congenital anomalies in 1932 Liveborn deliveries from 1993 to 1996 to HIV-infected women in the state of New York (NYS), U.S.A.. Prevalence of a nomalies in the cohort was compared with that of a general NYS population. Within the cohort, adjusted odds of any anomaly were compared by receipt of ZDV and by trimester of first prescription. Results: The adjusted prevalence of any anomaly in the study cohort was 2.7 6 times greater than in the general population (95% confidence interval [CI ], 2.36-3.17). Children of study women who were prescribed ZDV had increase d adjusted odds of any anomaly (adjusted odds ratio [OR], 1.55; 95% CI, 1.0 1-2.29). Adjusted ORs (with CIs) by trimester of first prescription were 1. 20 (0.58-2.51), 1.47 (0.85-2.55), and 1.84 (1.04-3.25) for the first, secon d, and third trimesters, respectively. Conclusion: Children of HIV-infected women in this cohort had a greater pre valence of major anomalies than did the general NYS population. An increase d risk of major anomalies was not evident for first trimester exposure when the association would have been most biologically plausible.