Recurrent miscarriage is defined as 3 or more consecutive spontaneous abortions with the same sexual partner. Although recurrent miscarriage is defined as 3 or more times, most experts believe that 2 consecutive miscarriages should be taken seriously and evaluated. Recurrent miscarriages are not only financially, physically and emotionally devastating, but often shake the stability of the marriage and family. As the number of miscarriages increases, the condition becomes more severe, making the recurrence rate of miscarriage higher and higher. In view of the fact that there is no special clinical manifestation to distinguish recurrent miscarriage from different causes, a comprehensive and systematic examination is often needed to clarify the causes and provide targeted treatment: a. Immune disorders are most common Reproductive immunology believes that pregnancy is a kind of allograft and the success of pregnancy depends on the immune balance between mother and fetus, once this balance is disrupted, it can lead to maternal immune rejection of the fetus and result in miscarriage. If this balance is disrupted, it can lead to maternal immune rejection of the fetus and result in miscarriage. There is no effective treatment for miscarriage caused by genetic factors, including chromosomal abnormalities of the couple, chromosomal abnormalities of the fetus, genetic abnormalities, etc. However, it is worth noting that these patients may be combined with immune disorders, which need to be checked at the same time to exclude, so as not to easily meet a normal fetus is not preserved. Endocrine disorders have methods 1, gynecological endocrine abnormalities common luteinizing insufficiency, hyperprolactinemia, polycystic ovary syndrome, etc.. These women are not easy to conceive and are prone to miscarriage after conception, so active fetal preservation treatment is very important. 2. Endocrine abnormalities in internal medicine Mainly diabetic women and patients with abnormal thyroid function (including hyperthyroidism and hypothyroidism), if women with these diseases have been found, they should be treated until the condition is stable before considering pregnancy to avoid miscarriage. On the other hand, recurrent women should have relevant tests in this regard to avoid missing the diagnosis. Fourth, anatomical miscarriage occurs late Uterine anatomical abnormalities (cervical insufficiency, malformation of uterine development) lead to recurrent miscarriage mostly in the late stage, and the diagnosis mainly relies on ultrasound, hysterosalpingography, hysteroscopy, laparoscopy and other examinations. Treatment is based on surgical correction, hysteroscopic surgery, or post-pregnancy cervical cerclage depending on the specific cause. V. Infections are common and indeterminate Patients with recurrent miscarriage have a high positive rate of various infections of the reproductive tract, such as Mycoplasma solium, Chlamydia, bacterial vaginosis, Candida vaginitis, etc. These women should be excluded and treated before conceiving again. Some women have congenital or acquired disorders of blood clotting mechanism, which makes their blood clot too fast, called pre-thrombotic state. Although normally there is no clotting in the blood vessels to form a thrombus, after pregnancy, these women have thrombus formation in the placental vessels, blocking the blood circulation of the placenta and causing the embryo to die from ischemia.