Early life trajectories of head circumference predict executive function and fluid cognitive skills at age 4 in Kenya

Head circumference (HC) is a low-cost proxy for early brain development, yet few studies have examined its predictive value for specific neurocognitive outcomes in low- and middle-income countries. This study investigated whether trajectories of HC growth from 1 to 24 months predict executive function and fluid cognitive skills at age 4 in a Kenyan cohort (N = 182). Using latent growth curve modeling, we found that greater HC growth was significantly associated with better EF and fluid cognitive skills, independent of initial HC and sociodemographic factors. These associations were robust across subgroups defined by prenatal exposure to HIV and atypical physical growth (i.e., extreme values for weight-for-length, underweight, or HC). Moreover, the predictive association between early HC and later neurocognition was evident within the first 15 months of life. This study highlights the value of monitoring changes in HC as one aspect of early child health and wellbeing. Infants who do not exhibit normative increases in HC in infancy may benefit from early neurocognitive assessments and/or the receipt of early intervention services.