Teratology in cultural documents and today.

Teratology is the science of congenital malformations. The incidence of birth defects amounts to 2-3%, but it doubles postnatal owing to the fact that many dysfunctions are not discernible at birth. Congenital malformations were already known in ancient cultures, records from Assyrian and Babylonian astrologists as well as from physicians and philosophers of the Hippocratic era are testifying it. In medieval times they were recognized as supernatural phenomenons, terata, from what the term TERATOLOGY derived. In the eyes of the superstitious people affected stillborns were regarded as monster, symbol of devil or miracle. The foundation of anatomy as a science by Vesalius marked the beginning of a reorientation. In the 17th century, when the age of enlightenment began, ideas concerning the origin of birth defects became more objective. Original studies dealing with congenital malformations became common in the 18th century. Fundamental discoveries made by microscopy placed Teratology on a truly scientific basis. Significant impetus was grown to teratological research with the discovery of Gregg (1941) that German measles (rubella virus) of pregnant women caused birth defects in the embryo and the contergan disaster (1959--1962). Congenital malformations originate from genetic factors (single gene defects and chromosomal aberrations) and environmental factors, such as radiation, drugs, chemicals, and infectious agents. The susceptibility of teratogen depends on the period of embryonal development, which is classified into gametogenesis, blastogenesis, embryogenesis and fetogenesis. The Food and Drug Administration of the USA published guidelines for teratogenetic testing (1966). There are in-vivo and in-vitro-test programmes, the latter became of increasing importance owing to the large number of chemicals to be tested and the activities of opponents against animal experiments. Although great advances were made, the problem remained to transfer results from in-vivo and in-vitro tests to the constitution of man without risk.