Some pregnant women receive subcutaneous injections of sodium heparin during pregnancy for several reasons. First, if a pregnant woman is determined to have a rheumatoid immune disease, such as positive antinuclear antibodies or systemic lupus erythematosus, anticoagulant therapy with sodium dheparin is needed to improve placental and umbilical cord blood flow and promote fetal growth and development. Second, if the pregnant woman's blood is in a state of high coagulation, the need for the use of heparin sodium anticoagulation therapy. Third, if a pregnant woman has a history of past thrombosis, she should be treated with dheparin during a second pregnancy.