With the general shift in the age of childbirth and changes in the overall environment, the number of recurrent miscarriages is gradually increasing, and most of these people in the clinic are more anxious and worried about the next pregnancy again, so what are the causes of recurrent miscarriages and what tests need to be done? Both parents have chromosomal abnormalities: the most common abnormality is chromosome balanced translocation. ② embryonic chromosomal abnormalities: so it is better to do chromosomal examination after clearing the uterus. 2, anatomical abnormalities of the reproductive tract: such as submucosal fibroids, longitudinal uterus, relaxed endocervical opening, and uterine adhesions (most commonly after repeated uterine operations, such as abortion). 3. Endocrine factors The most common ones are luteal insufficiency, abnormal thyroid function, etc. Polycystic ovary syndrome and hyperprolactinemia also increase the rate of miscarriage. 4.Infection factors The common five tests for teratogenicity are to check for infection factors. 5.Immunity factors 6.Also see unexplained miscarriage, most of which may be related to immunity factors. 1.Endocrine examination, including sex hormone and thyroid function examination, etc. 2, genetic factors, including the couple’s peripheral blood and miscarriage embryo chromosome examination, etc. 3. Immune factor examination: this involves more contents, including anti-cardiolipin antibody, anti-sperm antibody, anti-ovarian antibody, anti-endometrial antibody, anti-ovarian cell hyaline band antibody, anti-trophoblast cell membrane antibody. Also anti-thyroid antibodies, lupus factor, etc. In addition, there are also closed antibodies. The items carried out in different hospital levels are not consistent, and not all of them can be checked in general hospitals at present. 4.Infection factors: such as teratogenic five items, mycoplasma, chlamydia, etc. 5.Anatomical examination of the reproductive tract: ultrasound, hysterosalpingography, hysteroscopy and other examinations to exclude abnormal anatomy of the reproductive tract 6.Coagulation-related examinations Local microthrombosis may also cause miscarriage, so coagulation routine, D-II aggregates and other examinations to exclude coagulation-related miscarriage.