Anemia is a decrease in the number of red blood cells or the amount of hemoglobin in the blood, reducing the blood’s ability to carry oxygen. While anemia is primarily diagnosed through blood tests in adults, ultrasound plays a unique role in detecting fetal anemia through Doppler measurement of the peak systolic velocity in the middle cerebral artery. When a fetus is anemic, the blood flows faster because it is thinner and less viscous, causing elevated velocity readings in the brain’s arteries. This non-invasive technique has largely replaced the more risky procedure of cordocentesis for screening and monitoring fetal anemia in conditions like Rh incompatibility.
Sonography Term