Intrauterine growth and spastic cerebral palsy II. The association with morphology at birth.

This study tests the hypothesis that children with spastic cerebral palsy had different birth morphologies, defined in terms of their weight, length, head circumference, ponderal index and length to head circumference ratio, from that of the normal liveborn population. An earlier study showed a highly significant association of spastic cerebral palsy with low birthweight for gestational age in infants over 34 weeks gestation at delivery. This analysis defines morphological measurements as "abnormal" if not within the 10th-90th percentile ranges of appropriate total liveborn populations. The proportions with combinations of such measurements in 104 cases of spastic cerebral palsy from a population register of cerebral palsy are compared with those in a total liveborn population. Categories of 'abnormal' measurements associated with increased risk contained 44.4% of cases in excess of the proportion observed in the total population. More than half these excess cases were short for their gestation (suggesting size deficits originating before the 3rd trimester) and tended to have more severe forms of cerebral palsy. A further excess of 7.4% of cases had a head circumference above their 90th percentile: these generally developed mild cerebral palsy.