Doppler blood flow velocity waveforms in alpha-thalassemia hydrops fetalis.
Doppler shift blood flow velocity-time waveforms in the umbilical arteries (UA), aorta (A), and inferior vena cava (IVC) in eight fetuses with alpha-thalassemia (alpha-thal) hydrops fetalis were described. The UA waveforms in these fetuses with anemia in utero depicted a hyperdynamic circulatory state with a relative increase in acceleration slope, more linear decline from maximum systole to end diastole, and reduced spectral broadening. The aortic waveforms similarly displayed distorted systolic peaks, flow turbulence, and greatly elevated diastolic frequencies. Reversal of end diastolic flow in the IVC also indicated cardiac decompensation in these fetuses. Progressive changes in these waveforms were apparent in two fetuses that had serial evaluation. In another four fetuses in which alpha-thal major was diagnosed in the second trimester by DNA analysis and had Doppler evaluation before termination of pregnancy, consistent changes in the UA, A, and IVC waveforms were not observed. This study confirms the potential usefulness of Doppler spectral waveforms in depicting altered hemodynamic changes in the fetus and in the evaluation of hydrops fetalis. Doppler ultrasound examination can be included as part of the routine workup of hydrops fetalis.