In cooperation with the California Birth Defects Monitoring Program of the California Department of Health and the March of Dimes, NEB has participated in the establishment and is sharing in the utilization of a Population-based registry of children with cerebral palsy in four counties of the San Francisco Bay area for births between 1983-1985. In this birth cohort of approximately 156,000 children, 192 cases have been identified, excluding those with abnormalities related to events after the first month of life. Analysis using the examinations and birth certificates, and initial interview are in publication or preparation; those employing medical record review are imminent.