Doppler sonography for predicting fetal anemia caused by massive fetomaternal hemorrhage

Fetomaternal hemorrhage (FMH) can cause severe anemia in the fetus. Untreated, this may cause hydrops or even fetal death. However, correct diagnosis of FMH followed by blood transfusion can prevent these life-threatening consequences. We describe two cases in which fetal anemia was suspected because of maternal reporting of decreased or absent fetal movements, the detection of a sinusoidal heart rate pattern and increased blood flow velocities of the middle cerebral artery and umbilical vein. Together with the Betke-Kleihauer test showing fetal cells in the maternal circulation, this led to the correct diagnosis of severe fetal anemia caused by FMH. A Cesarean section was performed within a few hours. Both neonates were severely anemic and received immediate blood transfusions. They are currently alive and well.