Aspirin in early pregnancy, mainly for pregnant women with specific preeclampsia risk factors, is taken orally starting from 11-13+6 weeks of pregnancy at 100-150 mg daily until 36 weeks of pregnancy. Pre-eclampsia prediction is important for early prevention and early treatment to reduce maternal and infant mortality. Pregnant women with high-risk factors such as maternal age ≥ 40 years, history of pre-eclampsia, positive antiphospholipid antibodies or family history of pre-eclampsia, as well as by biochemical indicators, etc., are predicted to have high-risk factors for the occurrence of pre-eclampsia, and need to take oral aspirin to prevent pre-eclampsia.