Average 2.5‐year neurodevelopmental test results in children born very preterm did not rule out cognitive deficits at 6.5 years of age

AIM: The aim of the study was to investigate cognitive outcomes at 6.5 years in children born very preterm, in relation to neonatal characteristics and 2.5‐year neurodevelopment. METHODS: A prospective cohort, with gestational age 22.3‐31.9 weeks, born 2004‐2007, were examined at 2.5 years with the Bayley Scales of Infant and Toddler Development (Bayley‐III) (n = 100) and at 6.5 years with the Wechsler Intelligence Scales (n = 91). RESULTS: Neonatal factors independently related to 6.5‐year outcome were gestational age, retinopathy of prematurity and treated persistent ductus arteriosus. The Bayley‐III cognitive scores explained only 44% of the Full‐Scale Intelligence Quotient result at 6.5 years, and 22% of the children had Wechsler index results below −1 SD, indicating cognitive impairment, after average test results at 2.5 years. The relative risk to score below −1 SD on the Full‐Scale IQ was 2.83 (95% CI 1.45‐5.53) in children with gestational age below 28 weeks and 2.22 (95% CI 1.18‐4.17) at gestational age 28‐31 weeks. CONCLUSION: Very preterm infants born in the 2000s had increased risks for impaired cognition at 6.5 years, but individual predictions based on neonatal risks and 2.5‐year test results were not enough to identify all high‐risk children.