Calcium low molecular heparin costs$60-70 per 5,000 units. The treatment is once a day, one unit each time, subcutaneous injection. After two weeks of continuous use, the blood indexes are rechecked, and ultrasound is done to check the development of the embryo at the same time. Patients with thrombophilia should be applied if they have abnormal blood indexes such as protein S, protein C, cardiolipin antibody, blood coagulation four items, homocysteine and so on. Patients with thrombophilia have high blood coagulation, placental villous interstitial protein deposition and intravascular small thrombus formation, which can easily cause metamorphic membrane hemorrhage, resulting in reduced blood supply, and it is considered to be applied when pregnant women have biochemical pregnancy, spontaneous abortion, embryo cessation of development, fetal development retardation, amniotic fluid reduction, placental abruption, gestational hypertension and preeclampsia.