There is no direct evidence that hair dyeing during pregnancy affects fetal development, so it is recommended to go to the hospital during pregnancy for a formal checkup to find out if the fetus is developing normally. Hair dyeing, lipstick and nail polish after pregnancy can have certain toxic effects on the fetus. According to research by foreign medical doctors, hair dyes can not only cause skin cancer in the mother-to-be, but also lead to fetal malformation. Therefore, mothers-to-be should not use hair dyes. According to the information, hair dyes have teratogenic and carcinogenic effects on the fetus. Hair dyes contain a large number of harmful chemical components that can cause great damage to the soft tissues of the skin, and are even more harmful to people with skin allergies. Over time, the chemicals in hair dyes can also enter the bloodstream through the soft tissues and penetrate into the bone marrow from the blood, affecting the hematopoietic function and causing anemia or thrombocytopenia. Some hair dyes are potential carcinogens. Exposure of pregnant women to some hair dyes can also cause miscarriage in severe cases. As for the hair dye after pregnancy, it is not certain to cause fetal abnormalities child in the end can only be determined after going to a regular hospital for screening. In order to the health of the fetus, the mother-to-be must do a good job of pregnancy health care. Therefore, if a woman is pregnant with a scientific pregnancy health care, can be conducive to eugenics.