Umbilical vessel flow velocity waveforms in cord entanglement in a monoamnionic multiple gestation. A case report.

An unusual flow velocity waveform pattern was seen in a case of cord entanglement in a monoamnionic multiple pregnancy. The umbilical artery systolic:diastolic ratio was abnormally high (greater than 95th percentile for gestation), and diastolic notching was present. The umbilical vein flow velocity waveform was pulsatile, with flow absent during the diastolic phase of the cardiac cycle. The presence of that pattern strongly suggested a severe cord accident and mandated an immediate evaluation of fetal well-being.