Common precautions for the first trimester of pregnancy are as follows: 1, pre-pregnancy through routine laboratory tests to rule out hyperthyroidism, hypothyroidism, toxoplasmosis, giant cells and other eugenic tests, ultrasound, cervical pre-cancer screening, etc.; 2, the first trimester of pregnancy needs to be supplemented with folic acid, and pregnant women with a poor reproductive history need to be added to the amount of folic acid; 3, pay attention to rest, and keep your mood and mental well-being; 4, avoid contact with physical, chemical and other stimulating factors such as chemical agents, radiation, CT, etc..