We are searching data for your request:
Upon completion, a link will appear to access the found materials.
The belief in the utmost integrity of the fetus in the womb was staged by three dramatic events, which led to the twentieth century. The science of teratology (teratos = born, logos = science) was developed in the 20th century.
Norman McAlister GreggIn 1925, in the United States, it was recognized that X-rays also cause value disability, or, in less severe cases, microfichola. 1941 Norman McAlister Gregg, an Austrian eye has recognized that there has been a rubella swine fever in the background of congenital cataracts (cataracts) in the country. In November 1961, Widukind Lenz, a geneticist in West Germany, announced that the cause of late-stage malformation (phocomelia, e: focomyelia) was a particularly recommended sedation for pregnant women, Contergan volt. As it once was, the world "fell on the far side" and the "nothing good" period was taken by the "every good".
Fetal harm in the uterus
Teratological Basic LawsThe following is a description of some important basic laws of teratology.
- Specificity (noxa-specificity) means that the abnormality that occurs is specific to the cause. An abnormal acting cow cannot cause "everything" but a specific syndrome. Radiation is not capable of causing any brain damage.
- During the time factor, it is understood that an external effect can only induce its specific syndrome during a specific period of pregnancy. In most cases, the critical period is pregnancy 3-8. week. THE Before 3 weeks, the "law of all or nothing" is validated, that is, if the fetus is damaged, it will cause spontaneous abortion. If it stays, it's healthy. The only exception to this is the ionizing radiation, as the critical period of this effect is shown in Figures 12-18. during the week of pregnancy.
- The intensity of the external hazard determines the level of risk, that is to say, similarly to drug substances, it also has an environmental impact.
- The principle of species-specificity means that certain harm causes damage only under certain conditions. Contergan pl. proved to be harmless in all animal experiments. On the other hand, aspirin and prednisolone, which are not teratogenic in humans, are among the most dangerous drugs for laboratory animals. Unfortunately, species specificity greatly hampers teratological research.
- Individual Sensitivity: Almost no harm is sure to cause fetal harm. Therefore, we assume that environmental damage is also susceptible to genetic influences.