GROWTH AND DEVELOPMENT OF TWINS OF DISSIMILAR SIZE AT BIRTH.

Abstract

Birth records of a large private hospital and admissions records of a premature referral center, covering the period 1950 to [SEE TABLE VI IN SOURCE PDF] 1958 were reviewed. Twenty pairs of surviving twins were found in which the smaller twin weighed less than 2,000 gm and was at least 25% less than the weight of the larger twin at birth. Sixteen of these twenty pairs of twins were examined at a median age of 8½ years. Comparisons were made between the group composed of the smaller members of the twin sets and the group of their co-twins. A highly significant difference was present in height, head circumference, and weight. Significant differences in intelligence as measured by the Stanford-Binet and Peabody Picture Vocabulary Test, and in the judged level of language comprehension and expression were found. No significant difference was found between the groups in respect to articulation, oral structures, oral diadochokinesis or auditory acuity. Four of the children had important physical defects. Each child was the smaller member of a monozygotic twin set. Birth order showed no relationship to weight at birth or to subsequent development. A subgroup composed of monozygotic twins was studied. Results comparable to those for the total study group were obtained.