A color Doppler shows the blood flow in the uterine arteries. It allows the doctor to ascertain whether the placenta is functioning optimally. This can help the doctor decide if he can wait for forty weeks and beyond. If the test shows restricted blood flow then the doctor may suggest an induction if the baby is ready.

it's a scan done to check the blood flow to baby. as well as blood flow in baby body. functioning of placenta. how well it's supplying oxygen and blood to your baby.