The occurrence of 2 or more consecutive spontaneous abortions is called recurrent miscarriage (RSA). A miscarriage is defined as a termination before 28 weeks of gestation with a fetal weight of less than 1000 g. In 1977, the World Health Organization (WHO) defined miscarriage as a termination before 20 weeks of gestation with a fetal weight of less than 500 g. The classical theory defines spontaneous miscarriages that occur three or more times in a row as habitual miscarriages. Items that need to be examined for recurrent miscarriage: 1) karyotype examination of both spouses: chromosomal morphology and pathology examination of the miscarriage product to clarify whether it is a full embryonic developmental disorder or a specific developmental defect; 2) immunoradiological examination: (1) peripheral blood confinement antibody: confinement efficiency (BE), anti-unique antibody (AIA), cytotoxic antibody (CTA); (2) blood group: ABO, Rh factor and antibody potency; (3) complete set of infertility tests: anti-endometrial antibody, anti-ovarian antibody, anti-chorionic gonadotropin antibody; anti-cardiolipin antibody assay, anti-sperm antibody assay, anti-hyaline antibody; 3. endocrine hormone examination; 4. hysterosalpingography: to clarify whether there are uterine malformations, uterine adhesions, uterine insufficiency; 5. virological examination: Torch, mycoplasma, chlamydia, etc. 6. Semen routine examination: to further clarify the quality of fertilized eggs; 7. Hysteroscopy: to clarify submucosal fibroids, polyps, longitudinal uterine septum, adhesions, etc., while laser surgery is feasible; 8. Ultrasound examination: to clarify whether there are uterine fibroids, abnormalities, cervical insufficiency, etc. In recent years, recurrent miscarriages are becoming more and more common in the clinic, and most scholars believe that more than 80% of unexplained miscarriages are related to immune factors, and the negative closed antibody is one of the more important factors. In normal pregnancy, the paternal HLA antigens carried by the embryo can stimulate the maternal immune system to produce closed antibodies, therefore, clinically, the examination and treatment of closed antibodies are mostly seen in recurrent spontaneous miscarriage, embryonic arrest and empty sac in early pregnancy, slow intrauterine growth of the fetus in late pregnancy, or even fetal arrest and fetal death in utero, as well as repeated IVF failures. The treatment is usually used in cases of recurrent spontaneous miscarriage in early pregnancy, embryonic arrest, nulliparity, late pregnancy, slow intrauterine growth or even fetal arrest, intrauterine death, and repeated IVF failure.