Fetal peripheral bronchial fluid flow during breathing movement in normal pregnancies: a preliminary study.

Abstract

To determine the fluid flow velocity waveforms in the fetal peripheral bronchus during fetal breathing movement by means of pulsed Doppler ultrasonography. A preliminary cross-sectional study. Twenty-eight normal pregnant women between 32 and 38 weeks of gestation. Velocity waveforms from fetal peripheral respiratory fluid flow were acquired from the segmental bronchus (B6 or B8) which runs along the segmental artery (A6 or A8). The maximum velocity of the intrabronchial fluid flow and duration of inspiratory and expiratory phases were quantified. The flow velocity signal from the fluid in the fetal segmental bronchus of 17 of the 28 fetuses was detected. We observed two types of fetal breathing movement. During fetal breathing movement, the fluid in the fetal respiratory tract moves in the fetal segmental bronchus. This movement can be detected by pulsed Doppler velocimetry aided by power Doppler ultrasonography.