It usually refers to spontaneous abortions that occur three or more times in a row. What is the incidence of recurrent miscarriage in the population? 1% of women have a history of 3 or more consecutive spontaneous abortions. What causes recurrent miscarriages? The current medical literature indicates that the cause can be identified in only half of the cases, and the following causes can be identified: 1. Antiphospholipid syndrome: This disorder is associated with an abnormal tendency to clot, so that the small blood vessels of the placenta are easily blocked, leading to miscarriage. 2. Structural abnormalities of the uterus: About 10% of patients with recurrent miscarriage can be found to have structural abnormalities of the uterus. These include: fibroids convex to the uterine cavity, uterine longitudinal septum or uterine adhesions (endometrial scarring after adhesions). The mechanism of miscarriage is uncertain and may be related to the location of the pregnant egg implantation. 3. Chromosomal abnormalities in both sexes: the chance of finding chromosomal abnormalities in both sexes in patients with recurrent miscarriage is 4%, compared to 0.2% abnormalities in the general population. 4. Cervical insufficiency (cervical laxity): cervical laxity usually causes miscarriage in mid-pregnancy (14-28 weeks) and rarely occurs in early pregnancy (less than 13 weeks). The typical history is: sudden vaginal flow in mid-pregnancy with painless spontaneous abortion. There is no definitive diagnosis. The current diagnosis is based mainly on the above history, followed by evaluation of the cervical condition during pregnancy by gynecological internal examination or ultrasonography. 5. Polycystic ovary syndrome: There is some evidence of correlation between polycystic ovary syndrome and recurrent miscarriage. About 10% of patients with recurrent miscarriage have polycystic ovary syndrome. 6, other coagulation disorders: In addition to antiphospholipid syndrome there are a number of other coagulation disorders associated with recurrent miscarriage, including antithrombin III deficiency, protein C or protein S resistance. 7. Immune factors: Immune factors causing recurrent miscarriage are controversial. This area has been debated in academic circles. 8. Infectious factors: In early miscarriage, infection does not seem to be the main cause. However, infections may cause preterm labor and miscarriage in the middle of pregnancy. Bacterial vaginosis is increasingly recognized as a possible cause of preterm and midtrimester miscarriage. 9. Unexplained recurrent miscarriage: Despite a series of tests, the cause cannot be found in approximately 50% of recurrent miscarriages. What tests are needed for recurrent miscarriage? The most important thing is to detect the underlying cause of recurrent miscarriage. If the cause is one of the above, the following tests are needed: 1. Blood tests: chromosomal, sex hormone and coagulation tests. 2. Iodine oil imaging of the fallopian tubes: to visualize the uterus and check the patency of the fallopian tubes under radiation. The contrast fluid is injected into the uterine cavity through the cervix to make the uterus visible under X-ray. When the contrast agent passes through the fallopian tubes, it can be used to find out whether the tubes are open and whether the umbilical ends of the tubes are open. The contrast is usually performed after menstruation and before ovulation (the first half of menstruation). Mild to moderate cramping abdominal pain caused by imaging can be treated with medication. Hysteroscopy: The uterus is an empty cavity. A slender hysteroscope is inserted into the uterus through the cervix to examine the uterine cavity under direct vision, usually under local anesthesia in an outpatient setting. It can check for lesions such as fibroids, longitudinal uterine septum and uterine adhesions (scarring). 4.B ultrasound: to exclude uterine fibroids, ovarian polycystic changes, etc. 5.Endometrial biopsy: A small amount of endometrium will be taken on the 21st day of menstruation for examination. What treatment can be given for recurrent miscarriage? Recurrent miscarriage should be treated for the cause: 1. Antiphospholipid syndrome and embolism-prone disease: Patients can take aspirin 75mg daily and subcutaneous heparin daily throughout pregnancy. 2. Uterine structural abnormalities: can be treated by hysteroscopic surgery. 3. Hormone therapy: Progestin: has been used for many years to treat miscarriage. HCG: HCG injections are beneficial for those patients with recurrent miscarriage who have irregular menstruation. 4. Polycystic ovary syndrome: Preliminary data suggest that laparoscopic ovarian perforation may reduce the incidence of miscarriage. 5, cervical insufficiency: cervical sutures may strengthen the cervical support. 6. Chromosomal abnormalities: A geneticist needs to be consulted. If necessary, donor eggs or sperm can be considered. 7. Immunotherapy: There are applications, but current evidence suggests that there is no clear benefit from immunotherapy. If you have experienced a miscarriage, you may be worried and fearful that it will happen again with your next pregnancy, and this is a normal feeling. However, you should know that exercise of average intensity does not usually increase the risk of miscarriage, nor do television, computers, or hairdryers increase the risk of miscarriage. However, smoking and alcohol consumption may cause miscarriage, so do not smoke or drink alcohol during pregnancy. Clinical studies consistently show that patients with recurrent miscarriages have improved pregnancy success with better management (specialized recurrent miscarriage clinics), care, and pregnancy monitoring guidance.