A newly published report from researchers at McGill University and a multinational team, including investigators from the University of Bristol and Harvard Medical School, evaluated the relationship between childhood growth trajectory and cognitive ability in a large, population-based cohort. 

In the study, 12,368 children born at term were followed up with cognitive assessment at ages 6.5 and 16 years. According to the article, NeuroTrax computerized cognitive testing was selected to measure cognition at 16 years in view of its strong test-retest reliability and correlation with traditional neuropsychological tests.

Highly controlled analyses revealed that overall size, timing of the childhood growth spurt, size at birth and post-infancy growth velocity were associated with cognitive ability at early school age and adolescence. Among the many control variables were type of delivery, delivery or postnatal complications, gender of the child, gestational age at birth, 5-minute Apgar score, and parental occupation. Different approaches were used to model continuous growth trajectory over time and to differentiate infant from post-infancy growth.

This International Journal of Epidemiology report is the first to document persistence of associations between early growth and later cognitive ability over time. The findings highlight the importance of considering children’s growth as a continuum from birth through childhood rather than in infancy alone when determining associations with later health outcomes like cognition. Notably, the study highlights the suitability of NeuroTrax testing for widespread implementation and its ability to meaningfully track cognitive function as it relates to clinical indicators.

The finding that child growth after infancy, but not during infancy, was associated with later cognition suggests that genetic and post-infancy environmental factors (e.g., nutrition) may play important roles in cognitive development. The authors point out that although rapid gain of weight and height in children has been linked to negative health outcomes, the current results suggest that faster child growth is associated with better cognitive abilities. Additional studies are needed to investigate whether the obtained associations persist into adulthood and evaluate important cognition-related life outcomes like academic success, educational attainment and employment.

Citation:
Ahmed, A., Kramer, M.S., Bernard, J.Y., Perez Trejo, M.E., Martin, R.M., Oken, E., and Yang, S. (2020). Early-childhood-growth trajectory and later cognitive ability: Evidence from a large prospective birth cohort of healthy term-born children. International Journal of Epidemiology. PMID: 32743654