Objectives: To investigate cognition, social adaptive functioning, behavior, and emotional development in the preschool period and to determine the effects of the age of onset of walking on those developmental areas in children who were born preterm without major neurodevelopmental impairments (NDI) early in life.
Methods: Fifty-eight children who were born preterm without major NDI early in life participated in this study. The Korean versions of the Wechsler Preschool and Primary Scale of Intelligence or the Bayley Scales of Infant Development, the social maturity scale, the Korean version of the Child Behavior Checklist (CBCL), Conners' abbreviated parent/teacher rating scale, the Childhood Autism Rating Scale, and a speech developmental test were administered. The participants were divided into two groups: early walkers (group A) and late walkers (group B).
Results: The full-scale intelligence quotient (IQ) and performance IQ were significantly lower in group B than in group A, while the verbal IQ did not differ significantly between the groups. The children in group B had greater risks of cognitive deficits than did the children in group A, especially in performance skills. The social quotient (SQ) was significantly lower in group B than in group A (p<0.05). The rates of mild or significant deficits based on SQ and the CBCL did not differ significantly between the groups. Four children in group A and one child in group B had attention/hyperactivity problems. One child in group A had autistic behavior. Only one child in group B showed a significant speech developmental delay.
Conclusions: Problems in cognition, social adaptive functioning, and emotional and behavioral development can occur in children without major NDI early in life. Late walkers had significantly lower scores in cognition and social adaptive functioning than did early walkers.
Keywords: Minimal brain dysfunction; Neuropsychological tests; Preterm birth.