Population based, controlled study of behavioural problems and psychiatric disorders in low birthweight children at 11 years of age.

OBJECTIVE To evaluate the risk of long term behavioural problems and psychiatric disorders associated with being born with low birth weight. DESIGN/STUDY GROUPS: A population based, controlled follow up study at 11 years of age of 130 low birthweight (LBW) children weighing less than 2000 g at birth who were without major handicaps, and a random sample of 131 normal birthweight (NBW) children born at term weighing over 3000 g. MAIN OUTCOME MEASURES Validated questionnaires addressing behaviour completed by mothers and teachers and child evaluation by child psychiatrist using a semistructured interview. RESULTS Behavioural problems, as defined by abnormal scores on more than four of 32 measures, were found in 40% of LBW children compared with 7% of NBW children (odds ratio (OR) 8.2, 95% confidence interval (CI) 3 to 25, p = 0001). A psychiatric disorder was diagnosed in 27% of the LBW children compared with 9% of the NBW children (OR 3.1, 95% CI 1.5 to 6.5, p = 0.001). The LBW children were more often inattentive, had social problems, and low self esteem. None of the pre-, neo-, or peri-natal variables in the LBW group were statistically significant predictors of behavioural outcomes or the presence of psychiatric disorders. Behavioural problems and psychiatric disorders were as common in those with birth weight less than 1500 g as those with birth weight 1500-2000 g. CONCLUSION An increased risk of behavioural problems and psychiatric disorders persists in LBW adolescents.