The teratogenic effect of drugs causes the appearance of defects, as well as abnormal development of the child due to their use by the mother during pregnancy. Teratogenesis develops under the influence of factors acting from the outside on the developing organism of the fetus, it is also possible under the influence of hereditary diseases.
What caused it?
The teratogenic effect is due to the passage of drugs or their transformation products through the barrier between the uterus and the placenta, resulting in disruption of the formation of organs and tissues of the embryo.
At various periods of pregnancy, various injuries occur, associated with the chronological formation of body structures - these are critical periods. The most dangerous in terms of the development of serious violations are the first 2-3 months of pregnancy. It should be noted that in earlier periods, under the influence of such factors, violations also occur in the developing organism, but they are incompatible with life: miscarriage occurs (spontaneous abortion). Critical periods for different organs are different: 23-28 day intrauterine development is important for the brain, 23-45 day - for the organ of vision, limbs are formed on 28-56 day and so on.
What factors cause?
The following factors induce teratogenic effects: drugs, infections (rubella, herpes, cytomegalovirus, parvovirus, syphilis, toxoplasmosis), metabolic disorders in a pregnant woman (endemic goiter, decompensated diabetes mellitus, prolonged hyperthermia, androgen-producing tumors), medicinal substances (andgene, I have already applied to the heart). , enalapril, iodides, tiamazol, tetracyclines, thalidomide, valproates, warfarin, busulfan), ionizing radiation (radiation therapy for cancer, therapy with radioactive iodine, adioaktivnye rainfall) and much more.
These factors affect with some features. Teratogenic effect due to dose. In addition, to the impact of any factor in the subliminal values of defects in the fetus is not formed. Teratogenic effects in different biological species and even in different representatives of the same species may be different, which is associated with the individual features of the metabolism (absorption, distribution and elimination in the mother’s body and directly penetrating the uteroplacental barrier). However, when exposed to the mother's body infection, it is impossible to determine the threshold dose.
Teratogenic factors are widely found in the environment. As a result of research, it was found that a woman takes about 3-4 medicinal substances during pregnancy. In addition, pregnant women may be at work or in everyday life in contact with various harmful compounds. The teratogenic effect of drugs must be established in studies: a link must be proved between the direct effect of the factor and the appearance of the defect with confirmation by epidemiological data. In addition, the influence of the factor must coincide with critical periods.