Population and case-control surveillance in the search for environmental causes of birth defects.

An important national health goal is to reduce morbidity attributable to birth defects and developmental disabilities. Population-based surveillance has made notable contributions toward preventing these problems; it is also useful in monitoring changes in their incidence and in helping to identify reproductive hazards in the environment. The Metropolitan Atlanta Congenital Defects Program of the Centers for Disease Control is a model for such surveillance activities. Its register contains data on birth defects of all infants born in the five-county metropolitan area since 1976. Information on all major malformations discernible by physical examination is collected by the register staff. Mothers of babies with selected major malformations are interviewed at length. The register data base permits testing of new hypotheses concerning birth defects. It has speeded an extensive study of the possible effects of military service in Vietnam on the risk of having a baby with a birth defect. In addition, because of their special skills, program staff have made contributions to genetic services and to the development of national policy on maternal serum alpha fetoprotein.