Recurrent spontaneous abortion (RSA) refers to the occurrence of two or more spontaneous abortions in a row. When recurrent abortion causes problems in the recovery of the uterus and body, it also brings heavy psychological burden to the patient. Why do we have repeated unavoidable miscarriages? What should we do in the next pregnancy? What can we do? Etiological analysis: Only about 50% of recurrent miscarriages can be identified as the etiological factor for their occurrence. Chromosomal abnormalities are the main cause, followed by maternal reproductive tract abnormalities, maternal endocrine abnormalities, immune function abnormalities, reproductive tract infections, cervical insufficiency and thrombotic tendency. (1) Chromosomal abnormalities: These include chromosomal abnormalities in the couple and chromosomal abnormalities in the embryo. Balanced translocation and Robertson translocation are the most common forms of chromosomal abnormalities in couples, so patients with recurrent miscarriage need chromosomal examination of both spouses to find the cause of embryonic abortion. The most frequent chromosomal abnormalities in embryos are triploidy, followed by polyploidy, X haploidy, autosomal haploidy, balanced translocation, deletion, chimerism, inversion, and overlap of chromosomes. Severe aberrations of genetic chromosomes can lead to low developmental potential of the embryo, which can lead to its natural elimination during development. Therefore, we recommend chromosomal examination and analysis of embryonic villi in patients who have miscarried to clarify the cause. For couples with chromosomal abnormalities or repeated chromosomal analysis of embryonic chorionic villi, pre-implantation genetic diagnosis (PGD) should be performed if necessary to reduce the incidence of miscarriage by in vitro screening of genomically normal embryos for intrauterine transfer. (2) Maternal endocrine factors: such as luteal insufficiency, polycystic ovary syndrome, thyroid disease and diabetes mellitus can affect the embryonic development potential due to maternal metabolic endocrine disorders. Therefore, patients with combined endocrine-related diseases need to be strictly followed up by specialists before and during pregnancy, and medication should be adjusted under the guidance of endocrinologists and reproductive and obstetrician-gynecologists. (3) Maternal reproductive tract infections and abnormalities: about 0.5-5% of recurrent miscarriages are associated with infections. The incidence of late pregnancy miscarriage and preterm delivery is increased in patients with bacterial vaginosis; endometritis or cervicitis caused by Chlamydia trachomatis and Mycoplasma hyopneumoniae can lead to miscarriage. Therefore, if you notice abnormal color or odor of vaginal discharge during pregnancy and delivery, you need to see a specialist promptly. Reproductive tract abnormalities include uterine malformations, cervical adhesions and cervical insufficiency. 15%-20% of recurrent spontaneous abortions are associated with uterine malformations. These include unicornuate uterus, bicornuate uterus, double uterus and uterine longitudinal septum. Among them, incomplete longitudinal uterus is most likely to lead to recurrent miscarriage. The endometrium of longitudinal septum is poorly developed, insensitive to steroid hormones and poorly supplied with blood, which leads to insufficient supply of nutrients and abnormal space for embryonic development, resulting in embryonic arrest. Therefore, before embryo transfer, hysteroscopy should be performed to understand whether the uterine cavity is suitable for embryo implantation, so as to reduce unnecessary embryo waste and increase the chance of pregnancy. (4) Abnormal maternal immune function and microthrombosis: Pregnancy is a successful semi-identical transfer process in which the pregnant woman shows immune tolerance to intrauterine embryo grafts without rejection due to a series of adaptive changes in her own immune system. If there is an imbalance of immune regulatory and suppressor cells, such as abnormal expression of HLA-G in trophoblast membranes, imbalance of NK cell subpopulation balance, imbalance of Thl/Th2 balance, abnormal protective and/or closed antibodies, abnormal cytokines secreted by macrophages, maternal immune hyporesponsiveness due to abnormal recognition of embryonic paternal antigens, resulting in maternal closed antibody or protective The lack of antibodies, immune rejection, and miscarriage occur. Therefore, for patients with recurrent miscarriages with normal chromosomes in both spouses and chorionic villi, we perform detailed immunological examination and treatment to down-regulate and close the immune system to reduce the chance of recurrent miscarriages. In addition, the formation of microthrombus in maternal-fetal blood circulation can affect the development and function of the placenta and the embryo’s nutrition supply, thus, patients with family history of thrombosis or risk factors for thrombosis will be given anticoagulation therapy to prevent miscarriage. (5) Other: Unhealthy lifestyle is associated with miscarriage. It has been reported that women who smoke more than 14 cigarettes per day have a 2-fold increased risk of miscarriage compared to the control group. The effects of alcohol abuse, excessive caffeine consumption, and environmental factors such as organic solvents and toxins. Obesity is associated with early miscarriage and recurrent miscarriage. Prevention: prevention is the most sought-after goal of treatment. In the face of recurrent miscarriage, what do we need to do to improve it? Adjust your mindset and change your lifestyle to reduce the occurrence of spontaneous abortion. (1) Regular life: adjust the work and rest time, appropriate exercise, avoid staying up late, irregular work and rest, etc. Adjust your work status and avoid excessive work pressure. (2) reasonable diet: food should be easy to digest, especially food rich in various vitamins and trace elements, such as vegetables, fruits, beans, etc. (3) Pay attention to personal hygiene: change your clothes more often and bathe regularly. Pay special attention to the cleanliness of the pubic area to prevent germs from infection. Clothes should be wide, and choose cotton breathable type of bottom is good. (4) Adjust your mentality before and during pregnancy, put down your burden of thought and prepare for pregnancy with ease and confidence. (5) Abstain from intercourse: for pregnant women with a history of spontaneous abortion, avoid intercourse within the third trimester of pregnancy. (6) Regular prenatal checkups: Regular prenatal checkups should be started early in pregnancy to facilitate timely detection and treatment of abnormalities by doctors and to guide pregnancy care. (7) Patients with recurrent miscarriage should be given treatment after the completion of relevant examinations under the guidance of doctors to clarify the cause, such as pre-transplantation genetic diagnosis (PGD), luteal support, immunotherapy, etc., if necessary, and strengthen treatment and monitoring before and during pregnancy. The human body is a complex structure with fine components, and a large gene pool finely encodes every step of our metabolism, and any disruption of the program can lead to the occurrence of organism-related diseases. Current medical technology does not yet allow us to pinpoint every step of the problem, but as we study ourselves more deeply, we are confident that we can understand and fix the wrong code of the program. Not only to have a child, but more importantly, to have a healthy child safely, which is the pursuit of millions of mothers and the pursuit of the C6 Reproductive Center.