Microcephaly levels in HIV-negative children born to mothers taking antiretroviral therapy in the U.S. are within the same range as that seen within the general population, researchers reported in The Lancet. However, efavirenz was associated with a higher risk for the birth defect, necessitating a nuanced provider-patient discussion about the best approach to treatment, the researchers suggested.
Microcephaly has been associated with a greater likelihood of neurodevelopmental impairment. In the current study, among a total of 3,055 children who were exposed to HIV at birth but did not become infected, 159 cases of microcephaly (5.2%) were identified when Nellhaus criteria were used; this number dropped to 70 when stricter SMARTT criteria were used.
Efavirenz use during pregnancy was found to double the relative risk of microcephaly by Nellhaus criteria, and to increase it by roughly 2.5-fold by SMARTT criteria. By contrast, darunavir use appeared to be protective.
In a related comment, Stanzi Maria le Roux of University of Cape Town and Elaine Abrams of the Mailman School of Public Health advised caution in interpreting the study results. Only 4.7% of the children in 2,983 mother-child pairs were exposed to efavirenz, they pointed out.
When treating pregnant people living with HIV, the first priority is preventing transmission of the virus to the child, but the next priority is to determine the safest antiretroviral regimen for the pregnant patient, they noted. They asserted that the benefits of antiretroviral therapy outweigh any concern about specific medications during pregnancy, but endorsed WHO’s recommendation of dolutegravir instead of efavirenz in those who might bear children.
Le Roux and Abrams also cautioned about the effects of alcohol use on both the fetus and antiretroviral adherence. They additionally noted that optimal treatment requires HIV diagnosis before pregnancy, and that in turn means access to family planning services—which is unavailable to many people across the globe. Similar studies in settings with a high HIV burden are also needed, they added.