Determinants of cognitive ability at 7 years: a longitudinal case-control study of children born small-for-gestational age at term.

The aim of this study was to identify the determinants of children's intelligence at 7 years, including pregnancy, postnatal, demographic factors, and small-for-gestational age (SGA) birth at term. Information was collected at birth (n = 871), 1 year (n = 744), 3.5 years (n = 550), and 7 years (n = 591). Approximately half of the children in this study were born SGA (birthweight <or=10th percentile). There was no significant difference found between IQ scores for SGA children compared to AGA children, after adjustment for potential confounders (p = 0.45). Paternal education, developmental delay, and birth order were associated with intelligence scores at 7 years in the multiple regression analysis. This study found no long-term effect of SGA birth at term on intelligence in middle childhood. Potentially modifiable postnatal and demographic factors were found to be strong predictors of intelligence at 7 years.