To establish the Z-score equation of right pulmonary artery (RPA) segments for some valuable pulse-wave Doppler parameters (PWD) and estimate their reference ranges in normal fetuses. Two hundred and seventy-three normal singleton fetuses at 18–38 weeks were enrolled in this fetal echocardiography of a prospective cross-sectional study. The proximal, middle, and distal segments of RPA of pulsed-wave Doppler parameters, such as peak systolic velocity (PSV) and pulsation index (PI) were obtained by using fetal Doppler...