Hair coloring is not recommended for pregnant women. Many hair dyes are chemicals that contain many harmful substances that can be easily absorbed by pregnant women, causing deformities and poor development of the baby. There are many harmful substances in hair dyes, and if the hair comes into contact with these substances during the process of hair coloring, they may pass through the hair follicles into the capillaries and enter the mother’s body, and may affect the child through the placenta. Especially in the first 3 months, in the process of development of various organ systems, may cause fetal malformation. Pregnant women who dye their hair may absorb toxic substances and damage their own liver and kidney functions. For the sake of their own health as well as the health of the fetus, pregnant women should not dye their hair, especially in the early stages of pregnancy.