Lottie
New Member
'Doppler ultrasounds' are done in the same way as abdominal ultrasounds, but they study the movement of blood (usually through a blood vessel). This technique has been used with pregnant women since 1977, primarily to examine the blood flowing through the unborn baby's umbilical cord. Since the 1980's Doppler ultrasound has also been used to look at blood flow between the uterus and placenta. Both tests aim to assess the functioning of the placenta and the well-being of the baby. Doppler ultrasounds tend to use higher intensities than 'diagnostic' abdominal and vaginal ultrasounds and emit continuous sound waves (not pulsed).
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Source: Link