The Antiretroviral Pregnancy Registry reports no increased rate of birth defects with atazanavir exposure

Data showing outcomes after atazanavir (ATV) exposure, from the Antiretroviral Pregnancy Registry (APR), were presented as a poster.

Pregnant women receiving ATV were enrolled from June 2003 (when the drug received FDA approval) and the analysis presented was performed to January 31 2010. Atazanavir is FDA pregnancy category B.

There were a total of 698 women with ATV-exposed pregnancies enrolled during this period and 588 were eligible for analysis. Their mean age was 29 years; 12.9% were white, 63.9% black and 16.7% Hispanic. The majority (87.9%) was American.

Of the 588 pregnancies, 18 were multiple gestations; 604 outcomes were recorded, including 567 live births. There were 12 live births with defects and one in an induced abortion. Of a total of 13 infants with birth defects, 8/368 were first trimester exposures giving a rate of 2.2% (95% CI, 0.9-4.2%) and 5/199 were second/third trimester exposures, with a rate of 2.5% (95% CI, 0.8-5.8%). The relative risk of defects of first trimester exposures to second/third trimester exposures was 0.87 (95% CI, 0.29-2.61).

The overall prevalence of birth defects among ATV-exposed infants was 2.3% (95% CI, 0.29-2.61), which the investigators noted compared favourably to the CDC MACDP general population rate for birth effects of 2.7% (95% CI, 2.68-2.76).

The organ systems affected included: heart/circulatory system, renal/urinary system, central nervous system, chromosome abnormal/anomaly, cleft hip/palate, other muscular/skeletal defects and specified syndromes.

Esker et al. Assessing the risk of birth defects associated with atazanavir exposure in pregnancy. 10th International Congress on Drug Therapy in HIV Infection, November 7-11. Glasgow. Poster 113. Published in Journal of the International AIDS Society 2010 13(Suppl 4):P113. http://www.jiasociety.org/content/13/S4/P113