Classification and registration of multiple congenital abnormalities.

The data processing of multiple congenital abnormalities is demonstrated in the Hungarian Surveillance of Congenital Anomalies. Specified dysmorphic syndromes and CA-associations are registered on the basis of notification. Unspecified multiple congenital abnormalities are evaluated on the basis of notified abnormalities. First, a distance-diagnosis is being tried concerning some specified dysmorphic syndromes and CA-associations. Second, the alive babies with unspecified multiple abnormalities are referred to the regional multiple abnormality centre while a detailed post-mortem description is requested from the stillborns and infant deaths with multiple abnormalities. Third, the remaining unspecified congenital abnormalities are divided into 4 categories (obvious, important, dubious and minor) and into 40 groups. Babies with two abnormalities are annually compiled in one table. Babies with three abnormalities are summarized according to the so-called "cardinal" abnormalities in different tables. Finally, babies with four or more abnormalities are listed one by one with regard to the leading abnormality in another table. This classification system helps - among other - to recognize known and new syndromes and CA-associations, as well as to monitor a cluster of specific combinations of congenital abnormalities.