The time of stopping heparin in late pregnancy is related to the physical condition of the pregnant woman, her condition and other factors, it can be stopped gradually after 37 weeks of pregnancy, or until 12-24 hours before termination of pregnancy. Heparin has an anticoagulant effect, can prevent thrombosis or various embolic diseases, can also be used for various causes of disseminated intravascular coagulation, need to determine the time of use and course of treatment according to the condition and constitution, pregnant women generally need to be used until after 37 weeks of pregnancy, and then gradually stop the drug. Heparin may appear after the use of spontaneous bleeding, alopecia, diarrhea and other adverse reactions, allergy to heparin, active bleeding, hemophilia, purpura, ulcer disease and other patients are prohibited to use the drug, it is recommended that pregnant women use the drug under the strict guidance of a physician.