Self-poisoning during pregnancy as a model for teratogenic risk estimation of drugs

The results of animal investigations cannot be directly extrapolated to pregnant women. Clinical and analytical epidemiological studies for human teratogenic risks have many inherent methodological problems and their predictions must be regarded with caution. Evaluation of the potential teratogenicity of extremely large doses of drugs in self-poisoned pregnant women who attempted suicide offers a unique model for finding associations between congenital abnormalities and different drugs. All self-poisoned patients were cared for at a toxicological inpatient clinic in Budapest, between 1960 and 1993. Out of 1044 pregnant women identified from three different periods of the project, 19 died. Women who survived were visited at home to reveal birth outcomes, and their children were evaluated medically to identify congenital abnormalities and to estimate cognitive-behavioral status. The previous or subsequent children of these pregnant women were used as controls. In general, self-poisoned pregnant women were young (peak age was 18 to 20 years) and primiparous; 55% were unmarried and of lower socioeconomic status. Suicide attempts with drugs were most frequent in the fourth postconceptional week and second pregnancy month. Of 1044 self-poisoned pregnant women, 411 delivered live-born babies, of which 367 children (89.3%) were evaluated. The self-poisoning model appears to have several benefits (e.g., dose-response estimation) in comparison with other methods. It is suggested that an international monitoring system of self-poisoned pregnant women should be established to provide a larger database.