Neurological outcome of twins dissimilar in size at birth.

The neurological outcome of dissimilar twins was studied in 22 pairs of babies having a birth weight difference of 25% or more (mean 1748 vs. 2531 g). In weight, height and head circumference no statistically significant difference could be found at the study time (mean age of the children 9.4 years) between the groups. In gross motor performance and mean school age grades there were no differences but in fine motor performance-balance-coordination (P less than 0.02) and visuomotor perception (P less than 0.01) a statistically significant difference was found favouring the larger group. It is concluded that dissimilarity carries an increased risk for signs of minimal brain dysfunction in the smaller twins.