This study aimed to evaluate the value of noninvasive Doppler ultrasonography in diagnosing fetal anemia due to maternal red-cell alloimmunization. The researchers measured hemoglobin concentrations and peak systolic velocity in the middle cerebral artery in 111 fetuses at risk for anemia. The results showed that an increased peak velocity of systolic blood flow in the middle cerebral artery had a 100% sensitivity for predicting moderate or severe anemia, regardless of the presence or absence of hydrops, with a false positive rate of 12%. The study concluded that Doppler ultrasonography can accurately detect moderate and severe anemia in fetuses at risk due to maternal red-cell alloimmunization without the need for invasive procedures like amniocentesis or cordocentesis.This study aimed to evaluate the value of noninvasive Doppler ultrasonography in diagnosing fetal anemia due to maternal red-cell alloimmunization. The researchers measured hemoglobin concentrations and peak systolic velocity in the middle cerebral artery in 111 fetuses at risk for anemia. The results showed that an increased peak velocity of systolic blood flow in the middle cerebral artery had a 100% sensitivity for predicting moderate or severe anemia, regardless of the presence or absence of hydrops, with a false positive rate of 12%. The study concluded that Doppler ultrasonography can accurately detect moderate and severe anemia in fetuses at risk due to maternal red-cell alloimmunization without the need for invasive procedures like amniocentesis or cordocentesis.