What is the risk of major congenital abnormalities among women on antiretroviral therapy?
More than 1.5 million HIV-infected women become pregnant yearly. An increasing percentage start antiretroviral therapy (ART) prior to pregnancy, resulting in a rapid rise in the number of first-trimester fetal ART exposures . Longer duration of ART in pregnancy decreases risk of Mother to child transmission of HIV , but there are also potential teratogenic effects which include congenital malformations, stillbirth, growth restriction, and preterm birth. Therefore, studies evaluating the safety of antiretroviral medications (ARVs) in pregnancy have been designated as a research priority. In this respect, we applaud the by Berard et al.  study ‘Antiretroviral combination use during pregnancy and the risk of major congenital abnormalities’ published by Berard et al. (AIDS, vol 31:2267–2277) which observed no increased risk for congenital malformations in infants born to mothers prescribed first-trimester ART. The strengths of the study included the fact that it is population-based and collected many potential confounders. However, there are methodological limitations that compromise its ability to evaluate potential associations between ART and congenital malformations, notably an inappropriate comparison group (all women, regardless of HIV infection status), inappropriate measure of exposure (all ART regimens), and insufficient sample size of ART-exposed (n = 198).