Doppler measures of blood flow in right and left branches of the fetal pulmonary artery

Objective To compare Doppler blood flow velocity measures in the right and left proximal branch of the fetal pulmonary artery at 30 gestational weeks. Methods Doppler blood flow velocity waveforms were recorded in both fetal proximal pulmonary artery branches in 62 healthy fetuses at 30 gestational weeks. Pulsatility index, peak systolic velocity, time averaged maximum velocity, time velocity integral, fetal heart rate, acceleration- and ejection time with their ratio, time of one heart cycle and time velocity integral were recorded. Paired-samplest-test was used to compare measures from the right and left pulmonary branch. Results We observed significantly higher peak systolic velocity, time averaged maximum velocity, time velocity integral, acceleration time and acceleration time/ejection time ratio in the right compared to the left pulmonary artery (p < .001). Sampling angle, pulsatility index, fetal heart rate, ejection time and time of one heart cycle were similar in both pulmonary branches. Conclusion Our study conducted at 30 weeks gestational age found significantly different blood flow velocity waveform measures in the right and left pulmonary artery branches in contrast to previous reports of similar velocities.