Williams, Paige L.

Objective: To examine the impact of in-utero exposure to dolutegravir (DTG)-based or efavirenz (EFV)-based antiretroviral treatment (ART) on child neurodevelopmental outcomes. Design: Prospective cohort design, enrolling three cohorts of 2-year-olds: children HIV-negative born to mothers with HIV (CHEU) receiving either DTG-based or EFV-based three-drug ART during pregnancy, and children born to mothers without HIV (CHUU). Methods: Primary child neurodevelopmental outcomes were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) and compared between cohorts using generalized estimating equation models adjusted for confounders. Children were classified as having an ‘adverse ND outcome’ if they scored at least 1 standard deviation (SD) below the mean or were unable to complete the BSID-III. Results: Five hundred and sixty-four participants (202 DTG-exposed, 202 EFV-exposed, 160 HIV-unexposed; mean age 25.7 months, 49% female). Mean (SD) Gross Motor scores were slightly lower among CHEU vs. CHUU [54.6 (3.6) vs. 55.6 (4.3)] and among EFV-exposed vs. DTG-exposed [54.3 (3.5) vs. 54.9 (3.6)]. CHEU were more likely to be classified as having an ‘adverse’ expressive language outcome [13.2 vs 7%, adjusted risk ratio (aRR) = 2.06, 95% confidence interval (CI) 1.05–4.03] than CHUU, but other neurodevelopmental outcomes were similar. DTG exposure was associated with less frequent ‘adverse’ classification in Cognitive (2.5 vs. 7.4%, aRR = 0.33, 95% CI 0.13–0.79) and Expressive Language domains (10.0 vs. 16.4%, aRR = 0.58, 95% CI 0.35, 0.95), compared to EFV exposure. Conclusion: Two-year neurodevelopmental outcomes among Botswana children DTG-exposed, EFV-exposed, and HIV-unexposed were mostly comparable. Children exposed in utero to EFV-based ART had higher risk of ‘adverse’ cognitive and expressive language outcomes compared with children DTG-exposed.

AbstractIntroductionStudies have reported a higher risk of suboptimal neurodevelopment among children who are HIV‐exposed uninfected (HEU) compared to children HIV‐unexposed uninfected (HUU). Actual academic performance among school‐aged children by HIV exposure status has not been studied.MethodsAcademic performance in Mathematics, Science, English, Setswana and overall among children enrolled in the Botswana‐based FLOURISH study who were attending public primary school and ranging in age from 7.1 to 14.6 years were compared by HIV exposure status using a Cochran‐Mantel‐Haenszel test. Lower academic performance was defined as a grade of “C” or lower (≤60%). Unadjusted and adjusted logistic regression models were fit to assess for an association between HIV exposure and lower academic performance.ResultsBetween April 2021 and December 2022, 398 children attending public primary school enrolled in the FLOURSH study, 307 (77%) were HEU. Median age was 9.4 years (IQR 8.9–10.2). Only 17.9% of children HEU were breastfeed versus 100% of children HUU. Among children HEU, 80.3% had foetal exposure to three‐drug antiretroviral treatment, 18.7% to zidovudine only and 1.0% had no antiretroviral exposure. Caregivers of children HEU were older compared to caregivers of children HUU (median 42 vs. 36 years) and more likely to have no or primary education only (15.0% vs. 1.1%). In unadjusted analyses, children HEU were more likely to have lower overall academic performance compared to their children HUU (odds ratio [OR]: 1.96 [95% confidence interval (CI): 1.16, 3.30]), and lower performance in Mathematics, Science and English. The association was attenuated after adjustment for maternal education, caregiver income, breastfeeding, low birth weight and child sex (aOR: 1.86 [95% CI: 0.78, 4.43]).ConclusionsIn this Botswana‐based cohort, primary school academic performance was lower among children HEU compared to children HUU. Biological and socio‐demographic factors, including child sex, appear to contribute to this difference. Further research is needed to identify modifiable contributors, develop screening tools to identify the risk of poor academic performance and design interventions to mitigate risk.

Greater understanding of the pathways through which an environmental mixture operates is important to design effective interventions. We present new methodology to estimate natural direct and indirect effects and controlled direct effects of a complex mixture exposure on an outcome through a mediator variable. We implement Bayesian Kernel Machine Regression (BKMR) to allow for all possible interactions and nonlinear effects of (1) the co‐exposures on the mediator, (2) the co‐exposures and mediator on the outcome, and (3) selected covariates on the mediator and/or outcome. From the posterior predictive distributions of the mediator and outcome, we simulate counterfactuals to obtain posterior samples, estimates, and credible intervals of the mediation effects. Our simulation study demonstrates that when the exposure‐mediator and exposure‐mediator‐outcome relationships are complex, BKMR‐Causal Mediation Analysis performs better than current mediation methods. We applied our methodology to quantify the contribution of birth length as a mediator between in utero co‐exposure to arsenic, manganese, and lead, and children's neurodevelopmental scores, in a prospective birth cohort in Bangladesh. Among younger children, we found a negative (adverse) association between the metal mixture and neurodevelopment. We also found evidence that birth length mediates the effect of exposure to the metal mixture on neurodevelopment for younger children. If birth length were fixed to its percentile value, the harmful effect of the metal mixture on neurodevelopment is attenuated, suggesting nutritional interventions to help increase fetal growth, and thus birth length, could potentially block the harmful effect of the metal mixture on neurodevelopment.