Generally, the fetus starts to grow hair in the fourth to fifth month of pregnancy, and the hair grows faster after the fifth month of pregnancy. During this period, women can also eat black sesame, walnuts and other types of food, can be conducive to the development of hair growth, and also conducive to the growth of brain cells. The specific time for the fetus to grow hair is sometimes related to the nutritional status and the physical development of the fetus. During the whole pregnancy period, we should pay attention to proper rest, maintain a regular life, eat more nutritious food, keep nutrition comprehensive and balanced, and also pay attention to relaxation, which is conducive to the normal growth and development of the fetus. In addition, it is also necessary to strengthen the maternity examination during pregnancy, to do ultrasound to observe the growth and development of the fetus, whether it is in line with the pregnancy week, so that the pregnant woman’s diet structure can be adjusted at any time, which is conducive to the normal growth and development of the fetus.