Spontaneous miscarriage is a condition in which the embryo or fetus is spontaneously expelled from the mother for some reason before the 28th week of pregnancy, and its incidence is about 15% to 20%. ERSA is a common obstetrical and gynecological disorder with complex and diverse etiologies related to the patient’s own genetic, anatomical, and internal factors. The causes of ERSA are complex and varied, and are related to the patient’s own genetic, anatomical, endocrine, immune, and infectious factors. 1, genetic causes about 3-8% of ERSA couples have chromosomal abnormalities, while the incidence of chromosomal abnormalities in the general population is only 0.2%; on the other hand, there may be no chromosomal abnormalities in both couples, but the embryo has a chromosomal combination error during development. Couples of advanced age are prone to chromosomal abnormalities in embryos. There is no effective treatment for patients with chromosomal abnormalities resulting in ERSA, and the incidence of chromosomally abnormal fetuses can only be estimated through genetic counseling. If the incidence is high, pre-implantation genetic diagnosis (PGD), donor sperm or donor egg IVF can be used to eliminate or avoid abnormal embryos; if the incidence is low, pregnancy can be initiated, followed by chorionic villus biopsy or amniocentesis to check fetal chromosomes and terminate the pregnancy once fatal or teratogenic abnormalities are detected. 2. uterine causes such as patients with uterine fibroids, uterine malformations or uterine adhesions are also prone to ERSA. In the case of malformations such as hypoplastic unicornuate uterus, bicornuate uterus and double uterus, surgery is difficult to correct and may result in miscarriage in late pregnancy. Such patients can be diagnosed clearly through ultrasound, hysterosalpingography, hysteroscopy, MRI and other examinations, and be treated effectively through hysteroscopic surgical plastic surgery. 3. Endocrine causes of ERSA are more common in patients with poor ovulation, luteal insufficiency, hyperprolactinemia and other endocrine factors, as well as abnormalities of the thyroid and adrenal glands that can easily lead to the above ovulation problems. ERSA caused by this kind of reason is best treated by endocrine therapy such as ovulation promotion and luteal support, and the success rate of pregnancy again after treatment can reach more than 90%. In recent years, studies have concluded that immune factors are also an important cause of ERSA. 50% to 60% of ERSA patients are immune-related, and about 30% of them are related to autoantibody production, which may be an autoimmune disease called autoimmune recurrent spontaneous abortion, based mainly on the detection of autoantibodies in these patients, with antiphospholipid antibodies being the most common. Other autoantibodies that can be detected are anti-nuclear antibodies. Another 70% of patients may be associated with hyporeactivity to fetal paternal antigens, called alloimmune recurrent spontaneous abortion, and these patients lack closed antibodies in their bodies. In humans, successful pregnancies are associated with the presence of confinement antibodies in the mother to protect the growing fetus, while patients with recurrent spontaneous abortions lack these antibodies. Studies have shown that the presence of confinement antibodies is indispensable for a successful human pregnancy and is involved in the immunoregulatory mechanisms between the mother and the fetus throughout the pregnancy. During pregnancy, these antibodies bind to paternal antigens at the maternal-fetal interface and prevent the fetus from being recognized by the maternal immune system, thus protecting the embryo from attack and rejection by the maternal immune system. In patients with ERSA who cannot produce sufficient confining antibodies, active immunotherapy with donor leukocytes (preferably the spouse) can successfully induce confining antibodies with a success rate of about 80% for another pregnancy.