Aortic pulse waveforms for evaluating cardiac performance in the human fetus.

Pulse waveforms of the fetal descending aorta were obtained using an echo-tracking system to clarify the gestational age-related changes and the usefulness for detecting cardiac dysfunction. Peak systolic (PSD) and end diastolic diameter (EDD), pulse amplitude (Amp) and Amp:EDD ratio, calculated from the pulse waveforms, were adopted for analysis. In 196 normal fetuses after 20 weeks, the PSD, EDD and Amp increased, and Amp:EDD ratio decreased linearly with advancing gestation. The 19 fetuses with suspected cardiac dysfunction were divided into healthy and altered cardiac function subgroups, according to the values of fractional shortening and preload index. Of these, 7 fetuses with cardiac dysfunction had significantly higher incidence of low Amp (p < 0.01) and Amp:EDD ratio (p < 0.001) than remaining 12 fetuses with normal cardiac function. The pulse waveform analysis in the fetal descending aorta proved useful for detecting fetal cardiac dysfunction in utero.