Abstract
OBJECTIVE: To characterise fetal brain growth in children with specific language impairment (SLI). DESIGN: A nested case-control study. SETTING: Perth, Western Australia. PARTICIPANTS: Thirty children meeting criteria for SLI at age 10 years were individually matched with a typically developing comparison child on sex, non-verbal ability, fetal gestational age, maternal age at conception, smoking and alcohol intake during pregnancy. MAIN OUTCOME MEASURES: Occipitofrontal head circumference (HC) was measured using ultrasonography at approximately 18 weeks gestation. Femur length provided a measure of fetal length. Occipitofrontal HC was measured at birth and at the 1-year postnatal follow-up using a precise paper tape measure, while crown-heel length acted as an index of body length at both time points. Raw data were transformed to z-scores using reference norms. RESULTS: The SLI group had a significantly smaller mean HC than the typically developing comparison children at birth, but there was no group difference at 18 weeks gestation or at the 1-year postnatal follow-up. Individual analyses found that 12 SLI children had an HC z-score less than -1 at birth, with three of these cases meeting criteria for microcephaly. There was no group difference in the indices of overall body size at any time point. CONCLUSIONS: Children with SLI are more likely to have a small HC at birth but not at 18 weeks gestation or infancy, suggesting growth asynchrony in brain development during the second half of pregnancy.