Fetal arrest refers to the cessation of embryonic development in early pregnancy due to some reasons, which may be manifested by the absence of fetal heartbeat or withering of the gestational sac, or by the irregularity of the gestational bud or fetus in the gestational sac during ultrasound examination. The main symptoms are small amount of vaginal bleeding and disappearance of early pregnancy reactions such as nausea and vomiting, breast tenderness, etc. The common causes of fetal abortion: 1. endocrine disorders: embryo implantation and development depend on the coordinated endocrine system in the mother, the early development of the embryo requires three important hormone levels to maintain, namely estrogen, progesterone, chorionic gonadotropin, if the endocrine function is abnormal, can cause miscarriage, the most common is luteal insufficiency, luteal insufficiency can cause delayed development of the endometrium The most common is luteal insufficiency, which can cause delayed endometrial development and short luteal phase, thus affecting the implantation of fertilized eggs, or insufficient support for further embryonic development, resulting in early pregnancy miscarriage. 2, genetic defects: the embryo itself factors, such as chromosomal abnormalities, or in the early development of the embryo some important tissues, organs are not normal development formation, this situation belongs to the natural elimination, that is, “the survival of the fittest, the inferior elimination”. Chromosomal abnormalities can be transmitted to the offspring by either spouse, and more than half of the embryos with chromosomal abnormalities are subject to early spontaneous abortion. The most common abnormal karyotypes are triploidy, such as trisomy 21, trisomy 16, trisomy 13 and trisomy 18, etc. Most of the embryos have difficulty surviving, and embryonic development stops or spontaneous abortion occurs. 3, maternal illness: pregnant women suffer from the following systemic diseases, such as severe diabetes, hypertension, heart disease, viral hepatitis, severe anemia, chronic nephritis or pregnant women have malnutrition, especially vitamin deficiency, as well as mercury, lead, alcohol poisoning, etc.; pregnant women are infected with viruses, such as rubella virus, cytomegalovirus, herpes simplex virus, toxoplasmosis or acute infectious diseases such as influenza, typhoid, pneumonia, etc. Reproductive organ diseases, such as uterine malformation, uterine fibroids or uterine adhesions. 4, immune system abnormalities: there is a complex and special immunological relationship between the embryo and the fetus and the mother, and this relationship makes the embryo and the fetus not be rejected. If the mother and fetus do not adapt to each other’s immunity, it can cause the mother to reject the fetus and prevent the development of the embryo, that is, “immune rejection”. If the maternal closed antibody is not enough during pregnancy, the pregnant woman produces too many antiphospholipid antibodies, the presence of anti-sperm antibodies, etc. Environmental factors: The change of physiological state during pregnancy makes the mother’s body more sensitive to the absorption, distribution and excretion of therapeutic drugs and various environmental harmful substances, and at the early stage of development, the embryo is extremely sensitive to the effects of therapeutic drugs and environmental factors, and various harmful factors can lead to embryo damage and even loss. Many drugs and environmental factors are important factors in causing early embryonic death or fetal malformations. Environmental hormones can act directly on the central neuroendocrine regulatory system, causing disruption of reproductive hormone secretion, decreased fertility and abnormal embryonic development. There are various environmental factors that cause miscarriage, including physical factors such as X-rays, microwaves, noise, ultrasound, high temperature, and heavy metals such as aluminum, lead, mercury, and zinc that affect the fertilized egg’s implantation or directly damage the embryo and cause miscarriage. Various chemical drugs such as dichlorohydrin, carbon disulfide, anesthetic gases, oral antidiabetic drugs, etc. can interfere with and impair reproductive function, causing embryo miscarriage, stillbirth, malformation, developmental delay and functional disorders. The company’s products and services are designed to meet the needs of the market. 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 organ diseases, such as uterine fibroids, premature ovarian failure or uterine adhesions can also stop the embryo development. Treatment after embryonic arrest: actively find the cause and treat the cause. Therefore, if a patient has embryonic arrest, he/she should go to the hospital to rule out all the causes in detail according to the above mentioned circumstances, but, unfortunately, sometimes the current level of medical development is not yet able to detect the specific cause in each case. Nevertheless, active search for the cause should not be neglected, and if the cause is found, treatment can be directed to the cause, while immunotherapy and endocrine therapy can be tried. 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