Brain structure and neurocognitive and behavioural function in adolescentswho were born very preterm

Background Infants born very preterm (<33 weeks) are at increased risk of n eurocognitive deficits. Their neurodevelopmental outcome up to age 8 years can be predicted by neonatal ultrasonography, but little is known of their later function. We investigated the effect of very preterm birth on brain s tructure and neurocognitive and behavioural functioning in adolescence. Methods A cohort of 105 infants born before 33 weeks of gestation in 1979-8 0 had ultrasonographic scans at University College Hospital, London, and we re prospectively examined at 1, 4, and 8 years. At age 14-15 years, 72 of t hose who remained in UK (cases) and 21 age-matched full-term controls under went brain magnetic resonance imaging (MRI), as well as neurological, cogni tive, and behavioural assessment. MRI images were assessed by two neuroradi ologists unaware of ultrasonographic findings or case or control status. Findings Of the 72 cases, 40 had unequivocally abnormal MRI and 15 had equi vocal scans. Of the 21 controls, one had abnormal and five equivocal MRI. A bnormalities of ventricles, corpus callosum, and white matter were especial ly common in cases. More brain lesions were identified by MRI than by neona tal ultrasonography. The cases had significantly more reading, adjustment, and neurological impairments than controls, but their behaviour was signifi cantly related to MRI abnormality. Interpretation Individuals born very preterm show an excess of neurocogniti ve and behavioural problems in adolescence, and more than half have abnorma l MRI brain scans.