Cognitive development in low risk preterm infants at 3-4 years of life.

BACKGROUND Major neurological handicaps and neuropsychological disturbances are more common in ex-preterm children than their counterparts born at term. OBJECTIVE To establish in a prospective study whether a characteristic neuropsychological profile exists in ex-preterm children who do not exhibit neurodevelopmental deficits on routine clinical examination. METHODS Thirty intellectually normal children born preterm (30-34 weeks gestation) without major neurological disabilities and a control group of term children matched for age, sex, and parental educational and occupational status were assessed at 3-4 years of age to obtain a complete neuropsychological profile. Intellectual ability, language comprehension and expression, perceptual and visual motor function, working memory, and attention and behavioural problems were investigated. RESULTS Even in the absence of major neurological signs, children born preterm achieved lower mean scores than controls on the Stanford-Binet intelligence scale (110.8 v 121, p<0.001), visual perception test (33.8 v 42.7, p<0.001), visual motor integration test (42.6 v 47.4, p = 0.049), memory for location test (8.4 v 9.5, p = 0.007), sustained attention test (41.6 v 51.5, p = 0.009), and the picture vocabulary test (33.3 v 44.7, p = 0.021). CONCLUSIONS Neuropsychological abnormalities can be detected early in childhood in apparently normal ex-preterm children and are consistent with a growing body of evidence that prematurity may be associated with long term neuropsychological morbidity in childhood and adolescence.