Growth in utero and cognitive function in adult life: follow up study of people born between 1920 and 1943

Abstract Objectives: To examine the relation between fetal growth and cognitive function in adult life. Design: A follow up study of men and women whose birth weights and other measurements of body size had been recorded at birth. Setting: Hertfordshire, Preston, and Sheffield. Subjects: 1576 men and women born in Hertfordshire, Sheffield, or Preston between 1920 and 1943. Main outcome measures: Intelligence quotient as measured by the AH4 test and amount of decline in cognitive function with age as estimated by the difference between score on the Mill Hill vocabulary test and score on the AH4 test. Results: Score on the intelligence test was higher in people who had a large biparietal head diameter at birth, but it was not related to any other measure of body size or proportions. No association was found between decline in cognitive function and any measure of size or proportions at birth. Conclusion: Impaired fetal growth was not associated with poorer cognitive performance in adult life. Adaptations made by the fetus in response to conditions that retard its growth seem to be largely successful in maintaining brain development. Key messages In humans, low birth weight and proportionate smallness at birth have been associated with poorer cognitive function in early childhood, but there have been few studies on whether this association persists into adult life There was no relation between body size or pro- portions at birth and either intelligence or cognitive decline related to age in over 1500 people aged between 48 and 74 years whose birth measurements had been recorded Fetal growth seems to be less important than genetic factors and environmental influences in postnatal life in determining adult cognitive performance Adaptations made by the fetus in response to conditions that retard its growth may be largely successful in maintaining brain development