Habitual abortion is defined as three or more consecutive spontaneous abortions with the same sexual partner, which may be due to a variety of reasons such as maternal factors, embryonic factors or other factors. 1. Maternal factors. The mother herself suffers from basic diseases, such as abnormal thyroid function, diabetes mellitus, positive anticardiolipin antibodies, closed antibody deficiency, congenital malformation of the uterus, cervical insufficiency, or uterine adhesions, etc., which may lead to miscarriage of habitual abortion after pregnancy. 2. Embryonic factors. Congenital developmental abnormalities of the embryo or chromosomal abnormalities caused by genetic mutations during embryonic development can also cause habitual abortion. 3. Other factors. Infection with rubella virus, herpes simplex virus and reproductive tract pathogens during pregnancy, or nuclear radiation hazards, radiation testing, environmental pollution, etc., can also cause habitual abortion. There are many causes of habitual abortion, habitual abortion should go to the hospital in time to do a detailed examination, for the specific causes of treatment.