It is generally recommended to start preparing for pregnancy three months after hair coloring. Hair dyes contain some harmful chemicals, and the quality of hair dyes on the market today varies, so if you get pregnant soon after dyeing your hair, it may have some effect on the pregnant woman and the fetus. From the perspective of eugenics, it is best to consider pregnancy after three months. Harmful substances in hair dyes may cause diseases such as contact dermatitis. Hair dyes are absorbed by the skin and enter the bloodstream, where they are broken down and detoxified through the liver. If pregnancy occurs within a short period of time, it is not fully metabolized in the body, and the harmful substances have a certain impact on the development of the fetus. Therefore, it is recommended that patients who want to get pregnant after dyeing or perming their hair should preferably wait for an interval of 3 months. Meanwhile, during the preparation for pregnancy, both husband and wife can do moderate aerobic exercise every day to improve the quality of sperm and eggs.