Specific language difficulties and school achievement in children born at 25 weeks of gestation or less.

To determine whether language and educational problems are specific or due to general cognitive deficits in children born at 25 weeks' gestation or less. A national cohort study assessed 241 of 308 (78%) surviving children at a median age of 6 years, 4 months along with 160 of these children's classmates. Formal tests included standard cognitive, language, phonetic, and speech assessments. The children's school achievement was rated by classroom teachers. Mean cognitive scores for index children were 82 (standard deviation [SD] +/- 19) compared with 106 (SD +/- 12) for the peer group. Extremely preterm children had an increased risk of language problems (odds ratio [OR] = 10; 95% confidence interval [CI] = 3 to 32), speech problems (OR = 4.4; 95% CI = 3 to 7), and overall school difficulties (OR = 25; 95% CI = 12 to 54). Extremely preterm boys were twice as likely to show deficits as extremely preterm girls, but no such sex-based differences were apparent in the comparison group. Differences in general cognitive scores explained specific language or phonetic awareness deficits, but not speech ratings or educational difficulties, in the extremely preterm children. Language or phonetic difficulties are not specific and indicate general cognitive functional difficulties. The findings have implications for models of global deviation of brain development in extremely preterm children.