Birth weight and cognitive function in the British 1946 birth cohort: longitudinal population based study
Birth weight is significantly associated with cognitive (mental) ability at age 8 years, through adolescence, and into early adulthood, independent of social background. Furthermore, birth weight is also associated with educational performance, finds a study in this week's BMJ.
Researchers at the MRC National Survey of Health and Development (the British 1946 birth cohort), based at University College London, examined the association between birth weight and cognitive ability in 3,900 males and females born in 1946, who had had cognitive assessments from childhood to middle life (measured at ages 8, 11, 15, 26 and 43). They also examined the association between birth weight and educational attainment in this group.
Birth weight was significantly and positively associated with cognitive ability at age 8 across the full birth weight range in the normal population, even after factors such as sex, father's social class, and mother's education and age were taken into account. This association was also seen at ages 11, 15 and 26, but at age 43, birth weight had no significant effect on any of the test scores. Birth weight was also associated with education, with those of higher birth weight more likely to have achieved higher qualifications.
Despite some inevitable limitations, these results support the view that birth weight is related to cognitive performance independently of social background, conclude the authors.
Contact:
Marcus Richards, MRC National Survey of Health and Development, University College London, UK Email: m.richards@ucl.ac.uk