The umbilical cord is the channel for the exchange of nutrients between the fetus and the mother. Abnormalities of the umbilical cord are one of the main causes of intrauterine distress, leading to perinatal deaths, and umbilical cord bypass is the most common, accounting for 13%-25% of all deliveries. Color Doppler ultrasound (color ultrasound) is currently the main method of prenatal diagnosis of fetal umbilical cord bypass, and detection of the ratio of the maximum systolic blood flow velocity (S) to the end-diastolic blood flow velocity (D) of the umbilical artery (S/D) is a major index; fetal heartbeat monitoring (NST) is the main method of determining the reserve capacity of the fetus. We performed combined measurement of umbilical artery blood flow and NST in 127 cases of pregnant women with umbilical cord bypass in order to monitor the survival status of the fetus in utero and give appropriate treatment according to the abnormalities, with good results, which are reported as follows. I. Methods Monitoring indexes and methods: (1) S/D value monitoring: using Japanese ALOKA5500 color ultrasound diagnostic instrument, 3.5MHz convex array probe, to detect S/D, to umbilical artery blood flow S/D value