Differences in child’s head circumference at 1, 3, 6 and 11 months of age between maternal educational levelsa.

*p-value **p-value SDS = standard-deviation score, BMI = body mass index.aValues are regression coefficients (95% confidence interval) and reflect the differences in head circumference (in standard deviation scores) in offspring of mothers with mid-high, mid-low and low educational level relative to children of women with high educational level. The values are derived from linear regression analyses performed on the data after multiple imputation of the covariates.bModel 1: adjusted for maternal age and parity.cFully adjusted model: adjusted for parity, maternal age, child’s height and weight (in SDS) at measurement of HC, birth weight SDS, gestational age, paternal and maternal height, pre-pregnancy BMI and breastfeeding (yes/no).dFully adjusted model: adjusted for parity, maternal age, birth weight SDS, gestational age, smoking during pregnancy, paternal and maternal height and pre-pregnancy BMI.