Hair coloring will have some effect on pregnancy, because the ingredients of hair dye are not safe, many hair dyes on the market contain nitrobenzene and heavy metals and other harmful chemicals: 1, it will harm the pregnant woman, in pregnancy, women’s body is more special, the skin is also more fragile, when dyeing hair dye will be penetrated into the body through the skin. 2, it will directly cause harm to the fetus, especially in the early stages of pregnancy, hair dye can cause headaches or vomiting. If women often dye their hair when they are pregnant, they may develop diseases such as dermatitis or urticaria, and may also cause headaches or vomiting.2. It can directly harm the fetus, especially in the early stages of pregnancy, the fetus is still unstable, and it is easy to affect fetal neurodevelopment, causing fetal malformations, and in severe cases, it can lead to miscarriage, so do not try to dye your hair when you’re pregnant.