HealthDay News — In utero exposure to efavirenz is associated with an increased risk for microcephaly among children who are HIV-exposed but uninfected, according to a study published online Nov. 15 in The Lancet HIV.
Paige L. Williams, Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues examined children aged younger than 18 years who were HIV-exposed but uninfected with at least one head circumference measurement while enrolled in the Surveillance Monitoring for ART Toxicities (SMARTT) study. Data were included for 3055 participants.
The researchers found that the cumulative incidence of microcephaly was 159 by Nellhaus criteria and 70 by SMARTT criteria during a median of 5.1 years of follow-up (5.2 [95% CI, 4.4-6.1] and 2.3 percent [95% CI, 1.8-2.9], respectively). In utero exposure to efavirenz correlated with an increased risk for microcephaly by both Nellhaus standards and SMARTT criteria (adjusted relative risks, 2.02 [95% CI, 1.16-3.51] and 2.56 [95% CI, 1.22-5.37], respectively). In children exposed to combination regimens containing efavirenz, these associations were more pronounced for regimens including zidovudine plus lamivudine than for those including tenofovir plus emtricitabine. Darunavir exposure had protective associations (adjusted relative risk, 0.50; 95% CI, 0.24 to 1.00). Compared with those without microcephaly, HIV-exposed but uninfected children with microcephaly had lower mean scores on neurodevelopmental assessments at ages 1 and 5 years and had an increased prevalence of neurodevelopmental impairment.
“The implications of our findings thus have broad global implications in low-resource settings in which efavirenz is used more widely, and emphasize the need for continued monitoring of long-term outcomes of new and existing antiretrovirals,” the authors write.