What is Colour Doppler Ultrasound?

• Colour Doppler ultrasound is used to measure the velocity of blood flow.
• Colour Doppler ultrasound can be used to listen to the fetal heartbeat, examine the fetal heart for defects, and estimate placental blood flow.
• During this special type of ultrasound, distinct colours show the different rates of blood flow.
• The colours show the location of fetal vessels thereby eliminating or confirming the diagnosis of Vasa Praevia.
• To eliminate false positive results for Vasa Praevia which may be caused by flash artifact sonographers should spend a little more time to make sure it persists. Alternatively, drop a pulse wave sample on the suspicious ‘flow’ to check that although it has colour it does not have the pulsalions that a fetal vessel would.

For a more detailed account of pitfalls and how to avoid them please download this educational presentation.

Vasa Praevia confirmed by Colour Doppler ultrasound (note the fetal pulse at 150bpm)
Courtesy and © 2007 www.thefetus.net