The definition of recurrence (RSA) is slightly different at home and abroad. At present, domestic abortion is usually called RSA 3 or more at 28 weeks of pregnancy.Abortion, the risk of abortion again is very high, and should be paid attention to.The epidemiological survey found that the incidence of RSA was about 1%to 3%, and in recent years, it has increased.
The recurrence risk of RSA has increased with the number of abortion. Studies have shown that for RSA, the history of natural abortion is an independent risk factor..
At present, the causes of natural abortion include chromosomal abnormalities, abnormal reproductive tract anatomy, endocrine disorders, infectious diseases, pre -thrombosis, and immune factors.In addition, more than 40%of the patient’s causes are unknown clinically, called unknown recurrence (URSA).
Chromosomal abnormalities are common causes of early RSA. The chromosomes here include spouse chromosomes and embryo chromosomes.
1.1 Division chromosomal abnormalities found about 3%to 8%of the abnormal sprinkled chromosomes in the RSA. The common chromosomal spitnds are mainly ease (61%) and Robertson Easy position (16%).Gene polymorphism, inverted arm, upside down, and abnormal chromosomal abnormalities.
If the husband and wife are the same carrier of the same Robertson, the embryo chromosomes may have a single or three -fold body, and the embryo may have an early abortion.About 2/3 of the children may have abortion or deformities.The risk of the inverted position between the spy chromosome arms is related to the length of the inverted clip. The longer the clip, the less likely to produce severe chromosomal malformations, and the lower the natural abortion rate, but the probability of embryonic abortion in the arm of the arm is higher.
If the wife carrys the defect X chromosomes, it may cause RSA [3-4] due to the asymmetric loss of the sloping X chromosome and the abnormal high incidence rate of the low-frequency X monomer.The non -rectification rate of male sperm also increased with age. Researchers conducted a nuclear analysis of sperm and found that the non -rectification rate of the male sperm in RSA patients increased significantly .
In recent years, some studies have found that Chinese men carry complex chromaton weights (Complex Chromosomal Rearrantement (CCR)) will also increase RSA .Analysis of chromosomes and fracture points accumulated by CCR found that CCR, which accumulates 6, No. 7, 8, 11, and No. 16, has adverse pregnancy endings. The breakpoints appear at 2Q31, 5Q35 and 8Q13. RSA is more common.It is reported that the micro -lack of Y chromosome is not related to RSA .
1.2 Embryo chromosomal abnormality in RSA is abnormal than the incidence of embryo chromosomal abnormality than that of husband and wife chromosomes. Among them, non -rectification of embryo chromosome is the most common abortion factor, especially in the early pregnancy .With the rise of women’s age, the incidence of ovarian mother cells’ non -rectification and multi -twice increases, especially in elderly women, the incidence of RSA has also increased significantly .SUZUMORI et al.  reportedly reported that 1309 patients with RSA were found to have a decrease in the proportion of embryo chromosome abnormalities as the number of natural miscarriage increased, and the probability of re -pregnancy miscarriage was greater.
Although the problem of chromosomal problems is difficult to solve, with the development of the auxiliary reproductive technology, the RSA caused by abnormal embryo chromosomes can be intervened through some new methods and new methods, such as micro -array technology, single nucleotide polymorphism and genomic hybridizationTechnologies, pre -implantation of genetic diagnosis technology to reduce the probability of RSA.
According to literature, about 8%to 15%of RSA is related to uterine malformations. Among them, recurrence abortion is accompanied by an incidence of congenital uterine development abnormalities of about 16.4%, and the incidence of recurrent abortion caused by abnormal uterine abnormalities is about 12%.In the abnormal reproductive tract anatomy, the most common is the most common in the uterine hypertrophy, the cervical mouth relaxation, the uterine fibroids and uterine morphology.
The development of congenital uterine development is mainly due to the formation and development of female reproductive organs. It is a complex process that is involved in joint participation in genetic factors and environmental factors. It is related to ionizing radiation, dyeing weight, and HOXA gene mutations in the external environment.
After the day after tomorrow, the sexual uterus abnormally appeared in adolescence, and was mostly related to the adhesion of the uterine cavity, the uterine fibroids and endometrial polyps .Inadequate cervical function may also cause RSA. Once discovered abortion, active treatment is needed.Ure adhesion is often caused by the narrowing of the uterine cavity, local inflammation of the endometrium, and fibrosis.The RSA caused by the uterine smooth fibroids may be related to the uterine fibroids caused by uterine cavity occupancy and insufficient local blood supply.Generally, RSA is more common in mucosal fibroids, and the impact of fibroids between muscle walls is less.
The common causes in endocrine disorders include lack of luteal function, Polycystic Ovarian Syndrome (PCOS), hypertrophic lesions and diabetes, thyroid diseases, high androgen levels, endometriosis, etc.
In the early RSA, the luteal function was less than 25%to 40%. The specific mechanism was unknown. It may not be related to progesterone. It affects endometrial development, embryo bed, and placental development is related to .Serum hypertrophic prolactin levels are closely related to the function of menstrual luteal or pregnancy luteal. High -centered prolactin ledin or low prolactin lesions may affect the end of pregnancy and cause abortion.The risk of natural abortion after pregnancy after pregnancy is higher than that of ordinary people, and the RSA incidence of PCOS patients is also high .
About 40%of the patients of PCOS are combined with Insulin Resistance (IR). Many research at home and abroad has found that there is correlation between IR and RSA, and IR increases the risk of RSA.At the same time, PCOS patients are often accompanied by obesity, poor endometrial tolerance, increased androgen levels, and tendencies of susceptibility , so it is easy to cause RSA.In recent years, with the advancement of reproductive medicine and endocrinology, more and more scholars have discovered that thyroid function has obvious correlation with pregnancy ending. The level of thyroid hormone (TSH) is closely related to abortion.Foreign researchers have found that the level of thyroid antibodies (ATAS) is related to RSA , but the specific pathogenesis is unclear.
In RSA, infectious diseases are reportedly accounting for about 8%to 10%. Although the proportion is not high, due to the high incidence of genital tract infections, the relationship with RSA must be valued .
After the giant cell virus infection, the body may have NK cells and tumor necrosis factor α being activated. The inflammatory reactions enhance the apoptosis, inhibit the cell nourishing layer cells, cause the embryonic bed ability, and eventually lead to RSA.After the Bacterial Vaginosis (BV) is infected, the endometriosis is induced. The increased peanitic acid and prostaglandin increase the development of the embryo bed and the placenta, which causes miscarriage.Some studies have also found that the UREAPLASMAUREALYTICUM (UU) infection can be detected in the body of RSA patients.Reproductive tract UU infection may cause chronic inflammation of the endometrium, interfere with the mother’s immune system, increase the synthesis of prostaglandin in the uterus, increase the contraction response, and affect the embryo bed and cause abortion.In addition, there are also reports of chlamydia, syphilis spiral body, and reproductive tract luster bacteria infection may be related to RSA .
Therefore, patients with RSA or patients with multiple outflow history should be checked before pregnancy before pregnancy.
5.1 The genome of the same type of immune fetus comes from the father and half from the mother side. For the mother’s body, the fetus is the same semi -album substance.EssenceIf the maternal immune balance is destroyed and the embryo is attacked by the human immune system, it may cause RSA .
The most common in the same type of immunity is T lymphocyte TH1/TH2 type, regulatory T cell (TREG), NATUral Killer, NK) cells and cytokines.TH is divided into TH1 and TH2 cells according to its different cytokines and functions.Most of the cytokines secreted by TH1 cells are mostly harmful to the embryo’s bed and development, while the factors secreted by TH2 cells are beneficial to the embryo’s bed and development.
During the normal pregnancy of the human body, the TH1/TH2 balance mode in the body is mainly TH2 factor; however, if the balance is turned to TH1, the embryo may be abnormal, even abortion or RSA.Treg is an independent cell sub -group formed in the thymus. It has heterogeneity and is involved in the immune response of the same type of heterogeneous fetus in the body. When the action of TREG is affected, it may cause RSA .
The common NK cells in immune are often divided into uterine natural killing cells (UNK) and peripheral blood natural killing cells (PNK). The functions of the two are different from the phenotype.In the early stages of embryo and early pregnancy, NK cells are the main types of endometrial white blood cells. The increase in UNK and the decrease in PNK are conducive to normal pregnancy maintenance.UNK is the main source of NK immunomaste factor, which can limit cytotoxic activity and conducive to the embryo bed.There is not enough evidence to prove that NK cell testing is beneficial to the diagnosis of RSA, and the significance of the number and proportional change is not clear. Therefore, NK cell testing is only recommended in clinical research .
5.2 About 20%of RSA patients with autoimmune diseases have autoimmune abnormalities. They can detect multiple antibodies in the body. The most common is antiphospholipid antibodies (APA).Anti -thyroid peroxidase and anti -thyroid globulin antibody and other non -organ specific antibodies.The mechanism of the APA caused RSA may be that APA can guide platelets and damaged blood vessel endothelial cells, which promotes thrombosis, especially the formation of placental molting vascular thrombosis, causing inflammatory response of the mother fetal interface, affecting the blood supply of the embryo and causing multiple miscarriage .
Vitamin D (Vitamin D, VD) plays an important role in regulating various immune effects cells including T cells, B cells and NK cells.VD deficiency increases the abnormal body fluid and cellular immunity, which may cause increased incidence of RSA .
The state before thrombosis may form micro thrombosis of the uterine placenta blood vessels, which causes natural abortion, which is closely related to RSA.Studies have confirmed that the conditional identification of the thrombosis in the plasma in RSA patients has changed.There are research reports that when coagulantlase original G20210A gene mutations can increase the risk of habitual abortion, especially women older than 29 .Another study has confirmed that the state of the thrombosis may cause a large cells around the fluff, the velvet vascular blockage and the interstitial hardening, so that the mother’s blood cannot pass through the velvet gap, which causes RSA.It is recommended to check the first state of the thrombosis as soon as possible for patients with RSA, which is of great significance for its clear cause and treatment.
In summary, RSA brings huge trauma to the physiology and psychology of infertile couples, and the cause analysis should be performed. Although its cause is complicated, the cause of its cause is comprehensive and comprehensive to screen for more targeted targetedness.
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