Aim: the aim of this study was to determine neuropsychological performance (possibly predictive of academic difficulties) and its relationship with cognitive development and maternal education in healthy preterm children of preschool age and age-matched comparison children born at term.
Method: a total of 35 infants who were born at less than 33 weeks' gestational age and who were free from major neurosensory disability (16 males, 19 females; mean gestational age 29.4wk, SD 2.2wk; mean birthweight 1257g, SD 327g) and 50 term-born comparison children (25 males, 25 females; mean birthweight 3459g, SD 585g) were assessed at 4 years of age. Cognition was measured using the Griffiths Mental Development scales while neuropsychological abilities (language, short-term memory, visual-motor and constructive spatial abilities, and visual processing) were assessed using standardized tests. Multivariable regression analysis was used to explore the effects of preterm birth and sociodemographic factors on cognition, and to adjust neuropsychological scores for cognitive level and maternal education.
Results: the mean total Griffiths score was significantly lower in preterm than in term children (97.4 vs 103.4; p<0.001). Factors associated with higher Griffiths score were maternal university education (β=6.2; 95% confidence interval [CI] 0.7-11.7) and having older siblings or a twin (β=4.0; 95% CI 0.5-7.6). At neuropsychological assessment, preterm children scored significantly lower than term comparison children in all tests except lexical production (Boston Naming Test) and visual-processing accuracy. After adjustment for cognitive level and maternal education, differences remained statistically significant for verbal fluency (p<0.05) and comprehension, short-term memory, and spatial abilities (p<0.01).
Interpretation: neuropsychological follow-up is also recommended for healthy very preterm children to identify strengths and challenges before school entry, and to plan interventions aimed at maximizing academic success.