Body size at birth, and in child-and adulthood and cognitive ability at 67.9 years.

Abbreviations: CI, confidence interval;

a

Cognitive ability test score was standardized and has a mean of 100 and a standard deviation of 15.

b

The adjusted model refers to adjustments made for length of gestation (birth measures), father's occupational status in childhood, parity, mother's age and height at delivery, history of breastfeeding, and age at testing cognitive ability at 67.9 years.

c

A further model adjusted for ‘b’ plus highest own achieved level of education. The marked associations were rendered non-significant. Unmarked associations remained as in the adjusted model ‘b’.

d

A further model adjusted for ‘b’ plus diagnoses of stroke and coronary heart disease. The marked associations were rendered non-significant. Unmarked associations remained as in the adjusted model ‘b’.

e

Regression coefficients, derived from linear regression analyses, reflect lower cognitive ability in standardized points (a) per each one standard deviation unit lower body size if the coefficient is positive, and (b) per each one standard deviation unit higher body size if the coefficient is negative.

f

Measurements of head circumference at two, seven, 11 and 20 years were not available.