Functional cardiac measurements performed by two-dimensional Doppler echocardiography in normal fetuses: Determination of Z-scores and future prospects

Two-dimensional (2D) echocardiogram with the aid of color Doppler and pulsed Doppler allows one to record blood flow waveforms in several structures of the heart. The determination of normal values of these flows in the fetus can help understand cardiac hemodynamics. Given this importance, numerous surveys have been conducted with various existing echocardiographic techniques in order to improve the functional evaluation and consequently, planning of delivery. The aim of this review was to discuss the findings of the reference values of blood flows obtained by 2D echocardiography with Doppler, the current trend of the determination of Z-scores in the functional measurements, and their future prospects.