Low molecular heparin calcium is usually injected until about one week after the fetal image has stabilized. Low-molecular heparin calcium has anticoagulant and antithrombotic effects and is suitable for pregnant women with placental blood circulation disorders or symptoms of miscarriage. The application of low molecular heparin calcium can effectively anticoagulate, thus achieving the purpose of ensuring the blood supply to the embryo and preserving the fetus. If the application time is short, it may be difficult to achieve the expected effect; long application time may cause coagulation disorders. After the injection of low molecular heparin, the pregnant woman also needs to have an ultrasound examination to understand the condition of the gestational sac. When the symptoms of miscarriage disappear and the gestational sac is well developed, the drug can be discontinued after one week of maintenance treatment. In addition, pregnant women who are on LCHF need to undergo liver and kidney function tests and coagulation tests (including D-dimer tests) to check for other complications.