Fetal heart rate below 120 beats per minute is considered intrauterine hypoxia. The main causes include insufficient maternal blood oxygen content, impaired transport and exchange of blood oxygen between mother and fetus, as well as the fetus itself due to disease factors. Hypoxia can be divided into acute fetal hypoxia and chronic fetal hypoxia. Acute fetal hypoxia is mainly caused by a variety of pathologies that lead to a sharp decrease in uterine blood supply, placental diseases that lead to obstacles in blood circulation and oxygen exchange between mother and fetus, or obstacles in umbilical cord blood flow, and the main causes are: I. Placenta praevia hemorrhage, placental abruption, uterine rupture. Improper use of medication for contraction, overdose of anesthesia and sedative drugs. Abnormalities of the umbilical cord, such as prolapse and torsion. IV. Serious hemodynamic abnormalities in the mother, such as acute blood loss, shock, cardiac failure, poisoning of the pregnant woman. Poor placental and fetal reserves associated with placental function and maternal complications are the cause of chronic hypoxia, and the main etiologic factors are: uteroplacental vascular pathology, such as gestational hypertension, diabetes mellitus, expired pregnancy, etc., which can lead to pathological changes in the placental vasculature, such as spasm, embolism, stenosis and so on, so that the interchorionic cavity is underperfused. Persistent low blood oxygen levels in the mother, e.g., cyanotic congenital heart disease in pregnant women, chronic heart failure, chronic pulmonary insufficiency, etc. Decreased ability of the fetal circulatory system to transport and utilize oxygen, such as when the fetus itself suffers from severe malformations of the cardiovascular system, and fetal anemia due to various causes, can lead to the existence of chronic hypoxia.