Embryonic arrest refers to the cessation of development of the embryo in early pregnancy for some reason. The ultrasound examination shows that the gestational sac has an irregular gestational bud or fetal morphology, no fetal heartbeat, or shows a withered gestational sac. The clinical category is miscarriage or stillbirth. The main etiology of embryonic abortion: first is chromosomal factor, chromosomal abnormality of the offspring is the main cause of early abortion; second is reproductive immune factor, if one has some kind of antibody, it will resist the development of embryo; third is uterine abnormal factor, such as unicornuate uterus, double uterus and bicornuate uterus leading to narrow cavity and restricted blood supply; uterine adhesion, mainly caused by factors such as induction and abortion leading to uterine trauma, infection or The normal molting and placental implantation are hindered by adhesions and fibrosis of the uterine cavity caused by residual placental tissues; reduced blood supply caused by uterine fibroids and endometriosis leads to ischemia and venous dilatation resulting in asynchronous molting and abnormal implantation; congenital or injured relaxation of the endocervical opening and the internal environment is that the endometrium is too thin or too thick will affect the implantation. The fourth is the reproductive endocrine factor. During the early development period of the embryo, it needs corresponding hormonal support such as estrogen, progesterone and chorionic gonadotropin, if the mother cannot provide sufficient hormonal support it can lead to embryonic abortion.