Congenital Malformation Surveillance System Based on Vital Records

ONE of the most interesting facets of the recent thalidomide tragedy was the long inter¬ val between the appearance of a substantial excess of drug-induced malformations and the time of withdrawal of the drug from the mar¬ ket.According to Taussig's description of the West German experience, this interval was at least 1 year (1).In retrospect, it is easy to understand why such a long delay occurred.Although this excess of malformations was large in total number of cases, it was distributed both geographically and temporally in the total population of births occurring in this interval.The chance that any one physician would see a large number of the cases was, therefore, small.