Pregnant women need to supplement different nutrients at each stage, such as folic acid in early pregnancy, iron rich food in mid-pregnancy, and calcium in late pregnancy. 1. Early pregnancy: women in early pregnancy need to supplement folic acid in a timely manner, such as eating more fruits, vegetables, etc., can also be taken orally under the guidance of a doctor folic acid tablets, because the early stage of pregnancy is a critical period of fetal neurodevelopment, supplementation of folic acid to prevent fetal neural tube deformities. 2. Mid-pregnancy: Women should supplement iron-rich foods, such as pig liver, egg yolk and other foods in mid-pregnancy, because pregnant women and the fetus need more iron during this period, and if they fail to supplement iron in time, it may lead to the occurrence of iron-deficiency anemia. 3. Late pregnancy: women should supplement calcium-rich foods, such as milk, etc., during late pregnancy, which is a critical period for fetal bone development, and if calcium is not supplemented in time, it may lead to congenital calcium deficiency in the fetus. In addition, pregnant women should pay attention to a balanced diet during pregnancy and eat more protein-rich foods, such as eggs, meat and other foods. If pregnant women in pregnancy after the diet can not meet the standard, it is recommended to timely consult a doctor, under the guidance of the doctor to improve the relevant examination, to take appropriate measures to treat.