Embryonic arrest refers to the cessation of embryonic development in early pregnancy due to certain reasons. Usually, there are no obvious clinical symptoms of embryonic arrest, which is mainly manifested as a small amount of vaginal bleeding, early pregnancy reactions such as nausea and vomiting, breast swelling and pain disappear. Causes of embryonic arrest: 1, endocrine disorders: embryo landing and development depends on the mother’s body to coordinate the endocrine system, the early development of the embryo, the need for three important hormone levels to maintain, that is, estrogen, progesterone, chorionic gonadotropin, if the endocrine dysfunction, can lead to miscarriage, which is most common is the luteal insufficiency, the luteal insufficiency can cause the development of the endometrium is delayed and short luteal phase, thus affecting the fertilization. Luteal insufficiency can cause delayed endometrial development and short luteal phase, thus affecting the implantation of fertilized eggs, or the further development of the embryo is not enough to support, resulting in early pregnancy abortion. Genetic defects: factors of the embryo itself, such as chromosomal abnormalities, or in the early development of certain important tissues, organs did not develop normally, this situation is a natural elimination, that is, “the survival of the fittest, the elimination of the inferior”. Chromosomal abnormalities in either spouse can be passed on to the offspring, and more than half of the embryos with chromosomal abnormalities undergo early spontaneous abortion. Chromosomal abnormalities include quantitative and structural abnormalities, the most common abnormal chromosome karyotypes for triploidy, such as trisomy 21, trisomy 16, trisomy 13 and trisomy 18, etc., most of the embryos are difficult to survive, the occurrence of embryonic arrest or spontaneous abortion. 3, maternal illness Pregnant women suffering from the following systemic diseases, such as severe diabetes, hypertension, heart disease, viral hepatitis, severe anemia, chronic nephritis or pregnant women with malnutrition, especially vitamin deficiency, as well as mercury, lead, alcoholism, etc.; pregnant women infected with viruses, such as rubella, cytomegalovirus, herpes simplex virus, toxoplasma gondii or suffering from influenza, typhoid fever, pneumonia and other acute infectious diseases; Diseases of reproductive organs, such as uterine malformation, uterine fibroids or uterine adhesions. 4.Abnormalities of the immune system There is a complex and special immunological relationship between the embryo and the fetus and the mother, which makes the embryo and the fetus not to be rejected. If the immunity between the mother and the fetus is not adapted, it can cause the rejection of the fetus by the mother and prevent the development of the embryo, i.e. “immune rejection”. Such as maternal closed antibody insufficiency during pregnancy, pregnant women with excessive production of antiphospholipid antibodies, the presence of anti-sperm antibodies. 5.Environmental factors The change of physiological state during pregnancy makes the mother’s body to the absorption, distribution and excretion of therapeutic drugs and all kinds of environmental hazardous substances have undergone a big change, in the early stage of development, the embryo is extremely sensitive to the influence of therapeutic drugs and environmental factors, and at this time, all kinds of hazardous factors can lead to the damage of the embryo, or even loss. Many drugs and environmental factors are important factors causing early embryonic death or fetal malformation. Environmental hormones can act directly on the central neuroendocrine regulatory system, causing reproductive hormone secretion disorders, reduced fertility and abnormal embryonic development. There are various environmental factors that cause miscarriage, including X-rays, microwaves, noise, ultrasound, high temperature and other physical factors, as well as heavy metals such as aluminum, lead, mercury and zinc, which affect the implantation of the fertilized egg or directly damage the embryo and lead to miscarriage. Various kinds of chemical drugs, such as dichloropropane, carbon disulfide, anesthetic gases, oral antidiabetic drugs, etc., can interfere with and damage the reproductive function, resulting in miscarriage, stillbirth, deformity, developmental delay and dysfunction of the embryo. As well as bad habits such as smoking, alcoholism, coffee, drugs, certain drugs and so on all affect the early embryonic development. 6, some other diseases such as severe diabetes, hypertension, heart disease, viral hepatitis, severe anemia, chronic nephritis, or pregnant women with malnutrition, especially vitamin deficiency, and reproductive diseases, such as uterine fibroids, premature ovarian failure or uterine adhesions will also make the embryo stop developing. Therefore, patients who experience embryonic arrest should go to the hospital to rule out the various causes in detail based on the above conditions, but, unfortunately, sometimes the current level of medical development is not yet able to detect the specific cause in each case. Nonetheless, active search for the cause should not be ignored. If the cause is found, treatment can be directed to the cause of the disease, and immunotherapy and endocrine therapy can be tried at the same time. It is also possible to change the living and working environment.