The length of treatment needs to be adjusted according to the individual condition of the pregnant woman and monitoring indicators, usually until 12-20 weeks of pregnancy, and some can keep treating women with recurrent miscarriage until delivery. Recurrent miscarriage refers to women who have suffered 2 or more spontaneous miscarriages in a row, and the commonly used treatment drugs are aspirin, low molecular heparin, prednisone and intravenous gammaglobulin. Aspirin can inhibit platelet aggregation, reduce thrombus formation and increase fetal blood flow, but it can pass the fetal barrier and inhibit the formation of thrombus, so it has the potential to increase the bleeding tendency. Low-molecular heparin has strong antithrombotic and weak anticoagulant effects, which not only inhibit thrombus formation rapidly and continuously, but also have an effect on the invasiveness and developmental ability of embryonic trophoblast cells while anticoagulating. Low-molecular heparin, on the other hand, does not increase fetal bleeding tendency because it cannot cross the placental barrier, and is non-toxic and non-teratogenic, making it a safe treatment. Currently, low-molecular heparin combined with low-dose aspirin for recurrent miscarriage can be intervened or combined with other fetal preservation treatment options, depending on the actual clinical situation.