The Preschool Intelligence of Oversized Newborns

Do children who were oversized at birth have a disadvantage in their potential for intellectual development? To study this question, all infants born of white mothers and who had intelligence tests at 4 years of age were selected from the Oregon records of the Collaborative Perinatal Study. I.Q. scores were compared on the basis of their birth weights, which were grouped as follows: (1) oversized, (2) low, and (3) the remainder. Of the children who were oversized at birth, 23% had an I.Q. below 80 compared to 10.6% found in those who were of usual weight at birth. This difference is significant at the 0.002 level.