Evaluation of drug intake during pregnancy in the Hungarian Case-Control Surveillance of Congenital Anomalies.

The data of the Hungarian Case-Control Surveillance of Congenital Anomalies, 1980-1987, were evaluated concerning drug intake during pregnancy in 10,698 index patients, 21,546 negative controls, and 828 positive controls (Down syndrome). Excluding pregnancy supplements, the proportion of no drug use was about 30% and the mean number of drugs used was 2.0 in the negative control group. These figures did not differ significantly from data of study and positive control groups. The analysis of most commonly used drugs indicated an extremely high proportion of hormonal support therapy. The teratogenic effect of several human teratogenic drugs was confirmed. However, their use is relatively rare and their attributable risk within the etiology of congenital anomalies is low, at about 0.3-1.0%. At present the teratogenic risk of drugs in humans is exaggerated and it has several unfortunate consequences: negligence in necessary drug use, unnecessary anxiety in pregnant women, and termination of planned pregnancies without any reasonable cause.