Pregnancy in the case of unknowingly do hair, if it is the use of perm aspect of chemical agents, due to which contains phenylenediamine, benzodiphenol, methylresorcinol, hydrogen peroxide, etc., a variety of toxic and harmful chemicals to the human body, after contact can accumulate in the body, increasing the risk of embryonic development stop, organ tissue malformation, miscarriage. The first trimester of pregnancy is an important period of rapid growth and development of various systems of the fetus, but also a teratogenic sensitive period, easy to internal and external adverse factors, the impact of abnormal development, is not recommended in the early stages of pregnancy on the hair perm, dyeing, straightening treatment. It is necessary to pay attention to strengthen the examination during pregnancy, to take blood test for chorionic gonadotropin, alpha-fetoprotein, estradiol level and ultrasound to check the thickness of fetal nuchal translucency, combined with the height, weight and other basic information of pregnant women, to conduct early Down’s syndrome screening.