The causes of fetal arrest can be attributed to the mother herself, the embryo and the father. 1. Mothers’ own reasons (1) Endocrine abnormalities: when the mother has endocrine abnormalities (such as luteal insufficiency, polycystic ovary syndrome, etc.), hypothyroidism or diabetic patients with poor glycemic control, etc., it will cause recurrent fetal arrest. (2) Abnormalities of immune function: abnormalities of autoimmune function, mostly seen in women with positive antiphospholipid antibodies, lupus anticoagulant factors, positive antinuclear antibodies, etc., and may also be accompanied by rheumatic immune diseases such as systemic lupus erythematosus, etc.; abnormalities of homozygous immune function, such as a lack of shutdown factors or an abnormally elevated number or activity of natural killer cells. 2. Embryonic factors: mainly due to chromosomal abnormalities of the embryo itself, including numerical and structural abnormalities, mostly seen in trisomy 18, trisomy 21, trisomy 13, or chromosomal translocation, inversion, deletion and so on. 3. Father factors: mainly caused by sperm chromosomal abnormalities. Therefore, it is always necessary to find out the cause and actively treat it under the guidance of doctors when the fetus is stopped.