A Doppler ultrasound is capable of detecting anemia in the fetus, by measuring the velocity of blood flow in the middle cerebral artery. This test is considered absolutely safe, also because it is non-invasive, and researchers believe that these tests can be used instead of amniocentesis.
This was established after Researchers from the University Medical Center in the Netherlands conducted a comparative study of the two methods in 165 fetuses. The finding revealed that the Doppler ultrasound was far more accurate in detecting anemia, especially in severe cases, than the amniocentesis test. Doppler ultrasound is found to be a highly reliable option in place of invasive screening in managing Rh-alloimmunization pregnancies.