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Science and Research

Is Birth Weight Tied to Brain Power?

Research Ties Baby Weight and Cognitive Development

Big babies may have an educational advantage, suggests a new study from Northwestern University’s Institute for Policy Research. The team of researchers, led by David Figlio, discovered that children who weighed more at birth were more likely to have higher test scores than lighter babies in the first breakthrough study to explore the interaction between school performance, birth weight and cognitive development.

The multidisciplinary team set out to explore the benefits of longer gestation and the accompanying weight gain, analyzing the relationship between birth weight and cognitive development in more than 1.3 million children and 15,000 pairs of twins. Following the children from birth through middle school through merged birth and school records, the researchers found that heavier newborns grew up to perform better in third through eighth grade. In the case of twins, the child that weighed more at birth tested higher than their sibling.

While the academic advantage seems to exist regardless of factors such as race, socioeconomic status or enrichment opportunities, a mother’s college education appears to be a larger predictor of cognitive excellence. With other factors at work, light weight babies can and do accomplish the same as and more than classmates with heavier birth weights.

Neonatal health, including birth weight, can affect adult outcomes as early as elementary school. By establishing a connection between birth weight and cognitive development, the Northwestern researchers hope to analyze the relationship between educational outcomes and the factors associated with high birth weight – high familial earnings, improved maternal nutrition and reduced maternal stress.