Inadequate blood supply to the umbilical cord may be related to the following conditions: 1. most commonly, placental malnutrition, low blood volume in the posterior placental blood pool, and poor blood supply to the umbilical cord. 2. in the most severe cases of placental abruption, the blood supply to the placenta decreases, and so does the blood supply to the umbilical cord, which can lead to fetal distress and intrauterine death in severe cases. 3. twisting of the umbilical cord, which can significantly affect the blood supply to the umbilical cord. 4. also related to the umbilical artery and umbilical vein travel, where the two arteries of the umbilical cord The two arteries of the umbilical cord run parallel to one vein, such as a train track, which is worse than two arteries running around one vein. 5. Abnormal attachment of the umbilical cord, such as attachment at the edge of the cord or sail-like attachment, can also affect the blood supply to the placenta. 6. The cord is too short, and the cord wraps around the neck, body and limbs, which also affects the blood supply to the umbilical cord.