Anencephalic Births in a Northern and a Southern Community: A Comparison

Although anencephalus is one of the more easily recognized congenital malformations, little reliable information is available concerning its geographic distribution. Accumulation of more precise information on its distribution might disclose a characteristic geographic pattern with areas of unusual concentration or relative paucity. If study were concentrated in such areas, the role of environmental and genetic factors in etiology could conceivably be clarified and, perhaps, a portion of anencephalic births prevented. The present paper gives the results of a comparative study of anencephalic births in two communities: Charleston County, South Carolina, and Halifax County, Nova Scotia. These communities are similar with respect to geographic extent and population size. The number of births per year in each is similar. Medical care facilities are comparable as reflected in the physician-to-population ratio and hospital-bed-to-population ratio. Each has a medical school and serves as a referral center for the surrounding area. Both are seaports and