Predicting preschool motor and cognitive performance in appropriate-for-gestational-age children born at ≤ 32 weeks gestation

Although many follow-up studies have been performed on preterm infants, little attention has been devoted to prediction of motor skills in the preschool or school years. We studied the relationship of performance on the Bayley Scales of Infant Development at a mean corrected age of 21 months to performance on the McCarthy Scales of Children's Abilities at a mean corrected age of 44.7 months for 43 appropriate-for-gestational-age (AGA) children born at ≤ 32 weeks gestation. Motor scores were stable over time with a significant correlation between the Bayley Psychomotor Developmental Index (PDI) and the McCarthy Motor subscale (r = 0.60; p = 0.0001). Scores of cognitive abilities also showed a significant correlation between the Bayley Mental Developmental Index (MDI) and the McCarthy General Cognitive Index (r = 0.42; p = 0.009). Small-for-gestational-age (SGA), very low-birthweight (≤ 1500 grams) children scored lower on the McCarthy General Cognitive Index (p = 0.01) and on the Motor subscale (p = 0.047) than the AGA children. We concluded that motor performance of AGA children born at ≤ 32 weeks gestation is stable from toddlerhood to preschool age. We suggest that SGA children be excluded from studies of motor performance of prematurely born children.