Fetal malformations and environmental influences. A perspective.

In western society, congenital malformations and genetic disorders have assumed much greater importance as causes of early morbidity and mortality, with the waning of infectious diseases. The personal and societal burden arising as a consequence is an important public health problem. Approximately 25-30% of admissions to major childrens' hospitals in the western hemisphere are for children with one of these disorders. About 3-4% of all births are associated with a major congenital malformation, genetic disorder, or mental retardation. For congenital malformations and mental retardation in particular, the causes may not be discernible in about two-thirds of cases. Clearly defined or suspected genetic origins have been delineated in almost 3,000 catalogued disorders, and many are thought to occur as a consequence of environmental/genetic interaction. The purpose of this paper is to provide some perspective on the influence of environmental factors in the etiology of congenital malformations.