According to statistics, the rate of umbilical cord knotting accounts for 0.3 - 2.2% of pregnancies and the mortality rate of fetuses with this condition is often 4 times higher than that of normal pregnancies. Therefore, umbilical cord knotting is a danger that "threatens" millions of pregnant mothers in our country and around the world. Recognizing the signs of umbilical cord knotting on ultrasound early will help pregnant women take timely measures.