Children whose mothers took antiretroviral medication for HIV/AIDS while pregnant may have higher risks for developmental delays at age 5, according to new research. Nonetheless, researchers said it’s essential for women with HIV to take antiretroviral therapy during pregnancy to prevent HIV transmission to their fetus. Women who have HIV and know it should start on antiretroviral therapy in case they do become pregnant, the authors said.

Researchers for the Pediatric HIV/AIDS Cohort Study, including Tzy-Jyun Yao of Harvard T.H. Chan School of Public Health, said the findings underscore the need to monitor the neurodevelopment of children whose mothers took antiretrovirals during pregnancy. They also called for a further look at the timing of a fetus’s first exposure to antiretrovirals in the womb. Among other findings, the risk of developmental delays was even higher for children whose mothers’ regimens contained the drug atazanavir, compared to regimens that did not. Worldwide, about 15.4 million children under 15 who were exposed to the virus in the womb do not have HIV because of the success of antiretroviral therapy. While the drugs significantly reduce the odds of pregnant women transmitting the virus to their fetus, past research has suggested the drugs may also increase the odds of delays in language and cognitive skills and behavioural challenges.

The authors said the developing fetal brain is susceptible to various environmental influences. It can be challenging to know whether the medications caused the delays or resulted from poor parental health, substance use or insufficient oxygen and nutrition.

Most previous studies of exposure to antiretroviral therapy in the uterus among children without HIV have evaluated only individual areas of neurodevelopment, the authors said. For this study, investigators evaluated the potential effects of the therapy on language, emotional-behavioural development and cognition. Children were assessed at age 5. Researchers compared exposure to regimens with atazanavir to drug combinations without it. They also examined whether these effects differed for children whose mothers received antiretroviral therapy before they got pregnant, compared to those whose mothers began treatment after they got pregnant.

Of 230 children whose mothers were already receiving treatment when they became pregnant, 15% had lower scores in one area of development, and 8% had challenges in at least two of the three, the study found. Among the 461 children whose mothers began therapy during pregnancy, 21% had a delay in one area and 12% had delays in at least two of the three developmental areas. Among the children whose mothers started treatment during pregnancy, those whose mothers’ regimens included atazanavir had a 70% greater chance of a developmental delay.