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.