Serious congenital malformations are a major contributor to the infant death rate worldwide. Their nonhereditary causes are multiple and complex, and include infectious and metabolic dangers, disease medication, nutritional inadequacy, medicinal products, environmental agents and pollutants, among them. The cause of many however is still unknown.The wide range of these causes makes the defects of interest to those of a wide range of medical and investigatory backgrounds, especialy clinicians, fundamental scientists, and environmentalists.