Infants born to women who used the anti-HIV drug tenofovir as part of an anti-HIV drug regimen during pregnancy do not weigh less at birth and are not of shorter length than infants born to women who used anti-HIV drug regimens that do not include tenofovir during pregnancy, according to findings from a National Institutes of Health network study. However, at 1 year of age, children born to the tenofovir-treated mothers were slightly shorter and had slightly smaller head circumferenceabout 1 centimeter each, on averagethan were infants whose mothers did not take tenofovir.

The study authors described the findings as reassuring, noting that the study did not identify any serious safety concerns during pregnancy for tenofovir. In combination with other anti-HIV drugs, tenofovir is the first line of treatment for adults with HIV. The researchers called for additional studies to follow the children as they grow and develop, to identify any potential long term effects of the treatment. Information on Tenofovir and formulations containing tenofovir is available at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000198/.

The study was undertaken because earlier studies had shown laboratory animals exposed to tenofovir in the womb were smaller at birth than were their unexposed peers.