Background: Brain development in early childhood is a key determinant of later cognition, social achievement and educational success. Head circumference (HC) measurements are a simple method to assess brain growth, yet reports of these measurements are uncommon in nutritional surveys of undernourished children.
Objective: To evaluate HC measurements in a population of rural Nepali children and relate these measurements to demographics, health and diet.
Methods: An observational study of head growth was nested within a longitudinal evaluation of a livestock-based agricultural intervention in rural Nepal. Between 538 and 689 children (aged 6 months to 8 years) were measured (height, weight, HC) at each of six survey visits. A total of 3652 HC measurements were obtained. Results were converted to Z-scores (WHO Anthro).
Results: Mean head circumference Z-scores (HCZ) diminished progressively over the first 4 years of life; a decline of 30% occurred between 3 and 4 years of age (-1.73 to -2.45, P < 0.0001). Overall, 56% of HCZ were <-2. Gender-adjusted HCZ (but not other measurements) were significantly lower for girls than boys [mean (SD) -2.31 (1.0) vs -1.99 (0.094), P < 0.0001]; girls more often had microcephaly (61% vs 50%, P < 0.0001). For children <3 years of age, HCZ were better in those who had eaten two or more animal-source foods (ASFs) within the previous 24 h [-1.69 (.05) vs -2.08 (0.10), P = 0.001] than in those who had eaten none or only one; HCZ correlated with the number of ASFs consumed (P < 0.001). Regression analyses demonstrated that the main determinants of HCZ were age, weight-for-age Z-scores (WAZ) and gender; 43% of the variance in HCZ in younger children was explained by WAZ and ASF consumption.
Conclusion: HCs reflect brain size in young children; brain size is linked to cognitive function. Poor head growth represents another facet of the 'silent emergency' of child undernutrition. Routine HCZ assessments may contribute to better understanding of the links between poverty and cognitive development.
Keywords: Animal source foods; Brain growth; Head growth; Malnutrition; Microcephaly; Nepal; Undernutrition.