[Registries of birth defects: a tool for monitoring, research, and evaluation of interventions]

This article examines the role of public health registries, based on the example of congenital abnormalities. In addition to their main role in epidemiological surveillance, registries can be useful for conducting research and for evaluating public health interventions such as primary prevention and prenatal diagnosis. Congenital abnormalities are relatively frequent, affecting about 3% of births, but many are due to rare diseases. Known teratogens increase the risk of one or afew specific, often rare anomalies. Consequently, continuous monitoring of large, geographically defined populations is needed, particularly to establish the "baseline "prevalence of birth defects. Networks of registries can make an important contribution to this goal, as exemplified by the EUROCAT network, which plays a key role in coordinating surveillance and research on birth defects in Europe.