What is a human teratogen: clinical and epidemiological criteria.

Known human teratogens explain only 6% of all birth defects. The epidemiological approaches used to study birth defects in human populations were reviewed together with some of the most important methodological problems encountered in this field. The criteria of causality to be met to conclude on the teratogenicity of a given substance were also discussed. A list of the known teratogens with mention of the main birth defects attributed to each of them is enclosed.