Images 1, 2: The images show gray scale scans of the true umbilical cord knot.

Images 3, 4: The images show color Doppler and power Doppler scans of the true umbilical cord knot.

Images 5, 6: The images show power Doppler scans of the true umbilical cord knot. The image 6 shows a normal spectral Doppler waveform of the umbilical artery at the level of the true umbilical cord knot, indicating the knot is still loose.

Image 7: 3D image of the true umbilical cord knot.

Images 8: Postnatal image showing the true umbilical cord knot.
