It is an ultrasound method to measure blood flow velocity. In color Doppler, the vessels are seen  in blue and red colors according to the course of the vessels, while in pulse doppler mode, it is possible to measure the flow velocity within the desired vein.

The most common and important  fields of use during pregnancy follow-up are:

1- Umbilical Artery (UA) Doppler : Fetuses with or suspicion of growth  umbilical cord  artery is examined.

2- Middle Cerebral Artery (MCA) Doppler : Especially used in the management of growth retardation after 32 th weeks.

3- Uterine Artery (UtA) Doppler : During 11-14 Weeks and 18-23 Weeks Detailed Ultrasound, The blood flow to the uterus is measured from both sides, right and left. It might be an important tool to determine the risk of preeclampsia and if we see an increased risk during 11-14 weeks scan a treatment is possible.

4- Ductus Venozus (DV) Doppler : The part of the vessel that passes the oxygenated blood from the umbilical cord within the fetal liver before connecting to the right atrium of the heart. It is used during 11-14 weeks scan and growth retarded fetus management.