A systematic registration was carried out in 1985-1986 and 1989 in 14 French 'departments' in order to assess whether the prevalence rates of different components of motor disability (MD) in three different birth cohorts (1972, 1976 and 1981) had changed at a time when the preterm birth rate and neonatal mortality were decreasing and there was evidence of changing perinatal practice. A total of 1355 MD were registered amongst resident children born in 1972, 1976 and 1981 with a prevalence of 3.34 per 1000. The prevalence of the MD types due to different causes did not differ significantly amongst the three birth cohorts with the exception of an excess of hereditary and degenerative disease of the central nervous system (CNS) among children born in 1981. The prevalence of cerebral palsy (CP) remained stable in the three birth cohorts: it was 1.30, 1.06 and 1.08 per 1000 respectively, for children born in 1972, 1976 and 1981. The prevalence of pre- or perinatal-origin of other motor disabilities (OMD) and of CNS malformations did not differ amongst the three birth cohorts. The method of registration is discussed and the results are related to those of the French perinatal surveys performed in 1972, 1976 and 1981, which showed a decrease in preterm birthrate, an increase in perinatal care and a decrease in the mortality rate of high-risk infants.
Adolescent Cerebral Palsy