Recurrent miscarriage is a very complex problem. Generally, three or more spontaneous miscarriages or cessation of embryonic development are called recurrent spontaneous miscarriages. Patients with recurrent miscarriage may have given birth to normal children. There are many causes of recurrent spontaneous abortion, 20-30% of which are unexplained. Another 20-30% have a more remote cause. This means that only about 50% have a very clear cause. Common possible or potential causes of recurrent spontaneous abortion include chromosomal abnormalities in both or one of the spouses, uterine fibroids, uterine longitudinal septum, uterine adhesions, infectious factors, luteal insufficiency, hypercoagulable blood, embryonic aneuploidy, immunological causes, etc. The treatment of recurrent spontaneous miscarriage is mainly directed at the etiology, and for unexplained miscarriage, combined medication is used to preserve the fetus. Many patients with recurrent spontaneous abortion of unknown origin require multiple pregnancies to obtain fertility.