VENOUS, ARTERIAL, AND INTRACARDIAC BLOOD FLOWS IN RED-BLOOD-CELL ISOIMMUNIZATION

Objective: To investigate the effect of anemia on fetal venous, arteri al, and intracardiac blood flows. Methods: Color flow Doppler was used to record flow-velocity waveforms from the atrioventricular valves, d uctus venosus, right hepatic vein, inferior vena cava, middle cerebral artery, and descending thoracic aorta from 38 cases of red blood cell isoimmunized pregnancies. Immediately after the Doppler studies, funi puncture was performed and the fetal hemoglobin concentration was meas ured. Results: Blood now velocities in the thoracic aorta, middle cere bral artery, and the ductus venosus were increased compared to referen ce ranges established previously; however, a significant association w ith the degree of anemia was found only for the velocity in the thorac ic aorta. Pulsatility indices in arteries and veins and the ratio of e arly to late atrioventricular inflow velocities were not significantly different from normal. Conclusions: Fetal anemia is associated with a hyperdynamic circulation in both arterial and venous vessels. Even in severe anemia, there is no evidence of congestive heart failure. Veno us and intracardiac Doppler studies do not provide a clinically useful contribution in the management of red blood cell isoimmunization.