Spontaneous abortion with 2 or more consecutive or non-consecutive occurrences is called recurrent spontaneous abortion (RSA) or recurrent spontaneous abortion. Recent studies have shown that the incidence of spontaneous abortion is much higher than the original statistics of 15%, and with the introduction of the concept of occult abortion, the current consensus is that the incidence of spontaneous abortion is 50-60%. Therefore, the actual incidence of RSA is higher than the above figures. The common etiologies are as follows: 1. Anatomical factors: Anatomical defects include uterine malformations, submucosal myomas, cervical insufficiency, etc. About 12-15% of women with RSA have uterine malformations, among which longitudinal uterus and cervical insufficiency are the most common. Usually, abortion caused by anatomical abnormalities occurs in very early or mid-pregnancy, and obstruction of implantation, insufficient blood supply or growth restriction are the possible mechanisms causing RSA. Diagnosis is usually made through medical history, ultrasound, hysterosalpingography, hysteroscopy and laparoscopy. 2. Endocrine factors: accounting for 10-20%, mainly referring to luteal insufficiency, hyperprolactinemia, endometriosis, polycystic ovary syndrome (PCOS), thyroid dysfunction and uncontrolled diabetes mellitus, among which luteal insufficiency is the most common. Diagnosis is made by medical history, physical examination and specific endocrine tests. 3, genetic factors: about 3-8% of RSA couples have chromosomal abnormalities, including patient couples and embryonic genetic defects. The most common chromosomal abnormalities in couples are balanced translocations, followed by monosomy, trisomy, chromosome breakage, inversion and deletion. Genetic abnormalities may also cause recurrent miscarriage, for example, certain HLA loci may be susceptibility genes for RSA, and certain genes related to coagulation function such as APCR and FvL gene mutations may be associated with RSA. Chromosomal abnormalities during gamete formation and embryo development are also important factors leading to recurrent miscarriage. Ageing eggs, chromosomal abnormalities in sperm, and adverse environment such as toxic chemicals, radiation, and high temperature can cause chromosomal abnormalities in embryos. Miscarriages caused by genetic defects are often early spontaneous abortions, and a definitive diagnosis requires careful collection of the couple’s reproductive history and family tree, and genetic testing of both spouses and the aborted product. During pregnancy, genetic examination of the fetus can be done through chorionic villus biopsy, amniocentesis, taking peripheral blood of pregnant women to separate fetal cells. 4, immunological factors: recent reproductive immunity research shows that about 50% to 60% of RSA is related to immunity.
of RSA is related to immunity, and early pregnancy abortion is more common. About 1/3 of them are related to autoantibodies, especially antiphospholipid antibodies (APA). About 2/3 of them may be an alloimmune disorder in which the embryo and trophoblast cells are rejected due to failure of semi-identical transfer. It may also be associated with the presence of anti-sperm antibodies (AsAb), blood group incompatibility, etc. The main test for autoimmune abnormalities is antiphospholipid antibodies. Since antiphospholipid antibodies can appear in the context of infection, clinical confirmation requires two positive tests with a 3-month interval. There is a lack of specific tests to identify recurrent miscarriage associated with homoimmunization. Immunological tests also include anti-sperm antibody test, blood group and anti-blood group antibody assay, anti-nuclear antibody and anti-thyroid antibody assay, and closed antibody test. 5. Infectious factors: Infectious factors associated with RSA include bacteria, mycoplasma, Chlamydia trachomatis, syphilis spirochetes, Burkholderia spirochetes, Toxoplasma gondii, herpes simplex virus and cytomegalovirus. Definitive diagnosis requires testing of pathogenic microorganisms such as serum or secretory TORCH, mycoplasma, and chlamydia. 6. Systemic diseases.
Severe cardiovascular disease, renal disease, blood diseases and certain sexually transmitted diseases (AIDS, syphilis, etc.) can lead to miscarriage in pregnant women; the incidence of RSA is significantly higher in patients with autoimmune diseases such as systemic lupus erythematosus and scleroderma. 7. Environmental factors.
Adverse factors in the environment, such as excessive exposure to harmful chemicals, excessive exposure to radiation, severe noise and vibration, excessive physical labor, alcoholism, smoking, drug addiction and other bad habits can also lead to spontaneous abortion. 8, male factors: male chromosomal abnormalities, alcoholism, smoking and other factors may affect the quality of sperm, which may cause RSA. 9, unknown causes: some RSA can not be identified at the current level of medical science, known as RSA of unknown cause. Therefore, couples with recurrent miscarriages should go to the hospital to ask a specialist to help you do the relevant examination, find the problem early treatment, and try to avoid the recurrence of misfortune.