Sonographic demonstration of nuchal cord and abnormal umbilical artery waveform heralding fetal distress.

Ultrasound examination of a 30-week fetus, appropriate for gestational age, revealed a nuchal cord and absence of end-diastolic velocities in the Doppler waveforms of the umbilical artery. Cardiotocography suggested impending fetal distress, clinically confirmed following expedient abdominal delivery. We suggest that Doppler velocimetry of the umbilical vessels may be useful in the assessment of viable fetuses with a sonographic diagnosis of a nuchal cord. Conversely, a nuchal cord should be considered as part of the differential diagnosis of abnormal Doppler velocimetry of the umbilical vessels.