Under what circumstances are expectant mothers likely to give birth to children with deformities?

　   How do deformed children come about?

　　Usually during the embryonic development stage, various harmful factors cause cell chromosome aberrations, or harmful substances inhibit cell mitosis, hindering fetus Deformities occur due to normal differentiation and development of organs.

　　Because the biosynthesis of embryonic cells is very active, cell differentiation, growth and development precede the rapid differentiation and proliferation of the cells themselves, so they are relatively fragile. In addition, the embryo's catabolism and excretion of toxins are very imperfect, and it is extremely vulnerable to damage by harmful factors and even cause malformations.

　　Common teratogens include microorganisms (such as viruses), drugs and certain chemical agents, certain metals and radioactive substances. Data show that among fatal factors, drugs account for about 1.5% and physical and chemical substances account for 1% ； Viruses and pregnancy disease Accounting for 1-3%, the cause has not yet been identified for 65%. It is worth noting that about 20% of teratogenic factors come from genetic diseases in parents rather than external environmental teratogens.

　　The type of malformation depends on the type of teratogen and its period of action. For example, rubella virus mainly causes cataracts, deafness and heart malformations, while congenital cytomegalovirus mainly damages the central nervous system. nerve The system produces microcephaly or hydrocephalus.

　　As for the period of action of teratogens, it is usually in the early stages of pregnancy (the first three months), because at this time the organs differentiate and develop rapidly and are most sensitive to external teratogens. Of course, different organ systems have corresponding teratogenic sensitivity periods. For example, the nervous system is 15-77 days after fertilization, the brain is 20-40 days after fertilization, the eyes are 24-39 days after fertilization, the limbs are 24-46 days after fertilization, and the external genitalia is 36-98 days after fertilization.

　　At 8 weeks after fertilization, the embryo has completed the differentiation of organs other than the nervous system and reproductive organs and entered the fetal stage, and its sensitivity to external teratogenic factors is relatively reduced. By 12 weeks after pregnancy, the influence of external teratogenic factors is smaller.

　　Which female Beware of giving birth to freaks

　　1. Women with high fever in early pregnancy

　　Even if the child of a woman who has high fever in early pregnancy does not have obvious appearance malformation, the brain tissue development may be adversely affected, manifesting as mental retardation and poor learning and reaction abilities. This kind of mental retardation is caused by high fever causing the death of fetal brain nerve cells and reducing the number of brain nerve cells. This kind of mental retardation cannot be recovered. Of course, fetal malformations caused by high fever are also related to pregnant women's sensitivity to high fever and other factors.

　　2. Pregnant women who like to be close to cats and dogs

　　Few people know that bacteria-carrying cats are also a source of infectious diseases that pose a great threat to fetal malformations, and cat feces is the main way to spread this vicious infectious disease. According to relevant information, in the UK, because pregnant women are close to cats, baby It causes adverse consequences, accounting for about 40% of infected pregnant women, and about 500 babies are killed by cats every year.

　　3. Women who wear heavy makeup every day

　　According to a survey in the United States, the incidence of fetal malformations among those who wear heavy makeup every day is 1.25 times that of those who do not wear heavy makeup. The main adverse effects on fetal abnormal development are arsenic, lead, mercury and other toxic substances contained in cosmetics. These substances are used by pregnant women. skin After being absorbed into the mucous membrane, it can pass through the blood-fetal barrier and enter the fetal blood circulation, affecting the normal development of the fetus. Secondly, some ingredients in cosmetics produce aromatic amines that have teratogenic effects after being exposed to ultraviolet rays in the sun.

　　4. Women who are stressed during pregnancy

　　Human emotions are controlled by the central nervous system and the endocrine system. Adrenocortical hormone, one of the endocrine systems, is closely related to human emotional changes. When pregnant women are emotionally stressed, adrenocortical hormones may hinder the integration of certain tissues in the embryo. If this occurs in the first 3 months of pregnancy, it may cause malformations such as cleft lip or cleft palate in the fetus.

　　5. Women who drink alcohol

　　If pregnant women drink alcohol, alcohol can pass through the placenta and enter the developing embryo, causing serious damage to the fetus. Drinking more than 2 glasses of wine a day during pregnancy may have an impact on the fetus and may even be dangerous ； Drinking 2-4 drinks a day is at risk of abnormal development. For example, the head is small, the ears and nose are extremely small, and the upper lip is wide.

　　6. Women who eat foods containing mycotoxins

　　Relevant experts point out that if pregnant women eat food contaminated with mycotoxins (moldy food), mycotoxins can pass through the placenta and harm the fetus, causing chromosome breakage in the fetal cells.