Congenital abnormalities: "is it wise to have another child?"

Congenital abnormalities affect some five per cent of all live births, and are a major factor in childhood morbidity and mortality. Most physicians, therefore, encounter a variety of developmental disorders, and must frequently deal with problems faced by a handicapped patient and his family. This task is becoming increasingly difficult with the growth and sophistication of genetic knowledge and changes in society's attitude toward medical practice. Although congenital abnormalities are classified according to a variety of presumed genetic or environmental 'causes', it is important to remember that most developmental disorders result from complex interactions of genes and environment, and that time is an important factor. Optimal understanding of a congenital defect may, therefore, be best achieved by study of a patient within the wider context of his family. The family history is one of the most powerful tools available in establishing a diagnosis and in answering parents' questions concerning prognosis and recurrence risk. Ultimately, however, decisions based on genetic counselling must be made by the parents themselves, within the context of their own fears, beliefs and aspirations.