Ultrasound reveals that the umbilical cord is wrapped around the neck in 70-80% of all births. The umbilical cord can wrap around the neck, body, hands, and feet, either temporarily or for a long time until birth; it can wrap around the neck once, twice, three times, or even more. This is related to the length of the umbilical cord. Why is the umbilical cord wrapped around the neck? Consider that if the fetus turns around or turns over in the uterus, it is easy to form the cord around the neck, there is already a week of the cord around the neck, if Ta turns around in the opposite direction, the cord around the neck does not exist, if it goes around again in the same direction it may add another circle. Therefore, only 30-40% of the umbilical cord is found to be wrapped around the neck at the time of delivery, and even fewer are wrapped more than two times. There is a relationship between cord entanglement and intrauterine fetal death. However, when cord entanglement is detected, do not worry too much because it can be predicted by regular prenatal fetal monitoring, counting fetal movements and ultrasound for amniotic fluid and umbilical artery S/D ratio. If the umbilical cord is too short or tightly wrapped after the cord is wrapped around the neck, the umbilical cord will be stretched and the fetal heart rate will be slowed down during the delivery. In some cases, there is no cord winding, but the cord is relatively short, i.e. less than 30 cm, which can also occur. In some cases, intrauterine hypoxia caused by the cord factor will manifest itself as a change in fetal movement, usually frequent fetal movements followed by fetal disappearance, before labor is initiated, which may cause irreparable damage if the last moment is missed. Therefore, it is especially important to count the fetal movements by yourself in case of umbilical cord entrapment. Please refer to the other article “What kind of fetal movement is normal”.