Increase in cerebral palsy in normal birthweight babies.

A register has been compiled of the 421 children with congenital cerebral palsy born between 1960 and 1975 from a defined geographical area of North East England (population 770 000). There was a fall in the rate of cerebral palsy among very low birthweight babies between 1964 and 1975 and also in the small group with dyskinetic cerebral palsy. The rate rose, however, among babies weighing more than 2.5 kg at birth in the second half of the study, in parallel with changes in perinatal mortality. The net effect is that the overall congenital cerebral palsy rate (mean 1.64 per 1000 livebirths) showed a gradual rise between 1968 and 1975. This conclusion is reinforced by evidence of a rise in incidence among the subgroup of patients with severe cerebral palsy (as defined by an interval measurement of handicap) during the same period.