The EUROCAT-registration of congenital anomalies and multiple births. Aims, methods and results of the Dutch register in the period 1981-1983

Aims, methods and results are described of a register of congenital anomalies and twins in the northeastern part of the Netherlands in the period 1981-1983. This register forms part of the European registry EUROCAT, a concerted action project of the EEC. Data were obtained on 460 newborns/foetuses in which a congenital anomaly had been found before the end of the first year after birth. This represents 2.0% of all births in that period and region. The percentage of underreporting has been estimated in the middle of 1984 as 23; more recently as ± 10 (middle 1985). The number of newborns/foetuses in the register belonging to multiple births was 355 (1.5%). The value of the register is illustrated with two examples: one where the register was consulted about a possible association of spina bifida with valproic acid use during pregnancy; and the other where the allegation of a local epidemic of congenital anomalies in a village within the region was investigated through the register. On the basis of the experience obtained it is concluded that registration of congenital anomalies with present methods is feasible in the Netherlands.