Aetiological monitor of congenital abnormalities: a case-control surveillance system.

An Aetiological Monitor of Congenital Abnormalities was launched in Hungary on 1 January 1980 with the purpose to obtain aetiological information parallel with the reporting of congenital abnormalities. A questionnaire is sent to all mothers having babies with well defined major congenital abnormalities within one month after being reported to the Register. Diseases during pregnancy, drugs taken during pregnancy as well as employment and type of work made by the pregnant are studied. According to the data of the first year, progestogens were taken in 33.4% and oestrogen in 10.8% of all pregnancies. Other data indicate that the drugs studied mean either no teratogenic risk or, if there is any risk, it is very small.