Oxygen deficiency is most likely caused by placental abruption, umbilical cord problems or decreased blood circulation to the placenta. The exchange of gas and nutrients between the fetus and the mother is mainly through the placenta and umbilical cord, which is the main cause of hypoxia. The common problems of umbilical cord are: the umbilical cord is wrapped around the neck, the umbilical cord is knotted, the umbilical cord is twisted, the umbilical cord is too thin, etc.; the placenta is aging, there are foci of calcification, or the placenta is bleeding too much and affects the placental blood transport, etc. If the fetus is hypoxic in the uterus, it will generally be manifested as frequent fetal movements or reduced fetal movements, so self-counting fetal movements is especially important to detect fetal abnormalities in time, but any change in the regularity and number of times is recommended to actively come to the hospital to check the fetal heart monitoring and ultrasound, if it is a placental problem, you can try heparin and other intravenous drugs to improve placental microcirculation, if it indicates fetal distress, if necessary, emergency cesarean section to terminate the pregnancy, of course, also If the fetus is in distress, an emergency cesarean section may be necessary to terminate the pregnancy. The risk of intrauterine hypoxia may also be increased by complications during pregnancy, such as severe gestational diabetes and gestational hypertension. It is recommended to have regular checkups, count fetal movements, seek medical attention when abnormal fetal movements are detected, lie on the left side, and quit smoking and drinking to reduce complications.