Surprisingly the beginning of a modern approach This collection of articles and commentaries is an to the problems of birth defects is relatively recent integration of information from many disciplines and dates from Greggs classical report in 1941 that and presents a comprehensive survey of both recent mothers who contracted rubella during the first tri and previously reported work related to the major mester of pregnancy gave birth to infants with severe aspects of birth defects. In particular an attempt multiple anomalies. For the first time an environ has been made to provide a critical assessment of mental agent was found to be teratogenic in man current concepts and to identify areas in need of and was documented in a thoroughly convincing further investigation.