Neurodevelopmental Outcomes of High-Risk Preterm Infants

Abstract

Objectives:To determine the neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs, birth weight <1,500 g) after 9 years of follow-up.Methods:This study prospectively recruited 224 VLBWIs born from 2003 to 2009 in Kyushu University Hospital, Japan. Comorbidities of neurocognitive impairment, epilepsy, and autism spectrum disorder or attention-deficit hyperactivity disorder (ASD/ADHD) were assessed at 3, 6 and 9 years of age.Results:Neurodevelopmental profiles were obtained from 185 (83%), 150 (67%) and 119 (53%) participants at 3, 6 and 9 years of age, respectively. At 9 years of age, 25 (21%) VLBWIs showed intelligence quotient (IQ) <70, 11 (9%) developed epilepsy, and 14 (12%) had a diagnosis of ASD/ADHD. The prevalence of epilepsy was higher in children with an IQ <70 at age 9 than in those with an IQ ≥70 (44% vs. 0%). In contrast, ASD/ADHD appeared at similar frequencies in children with an IQ <70 (16%) and ≥70 (11%). Perinatal complications and severe brain lesions on magnetic resonance imaging were considered common perinatal risks for developmental delay and epilepsy but not for ASD/ADHD. Male sex was identified as a unique risk factor for ASD/ADHD.Conclusion:These data suggest that VLBWIs showed a higher prevalence of developmental delay, epilepsy and ASD/ADHD at 9 years of age than the general population. Distinct mechanisms might be involved in the pathogenic process of ASD/ADHD from those of developmental delay and epilepsy.