Since 1988 the epidemiological surveillance of congenital anomalies (malfor
mations, chromosomal aberrations, metabolic diseases, hereditary diseases,
neurosensorial defects, etc.) is carried out by the Swiss registry of EUROC
AT (European Registry of Congenital Anomalies and Twins). Several Swiss can
tons collaborate through their own local registry, transmitting data to the
central registry in Lausanne. We present the main objectives and methods o
f registration and give the global prevalence rates for the main malformati
ons for 1996 and the period 1993-1996.