title: Fetal peripheral bronchial fluid flow during breathing movement in normal pregnancies: a preliminary study.
abstract: OBJECTIVE
  To determine the fluid flow velocity waveforms in the fetal peripheral bronchus during fetal breathing movement by means of pulsed Doppler ultrasonography.
  
  
  METHODS
  A preliminary cross-sectional study.
  
  
  METHODS
  Twenty-eight normal pregnant women between 32 and 38 weeks of gestation.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, Osaka City University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
authors.forename: J
authors.initials: J
authors.lastname: Nishio
authors.forename: M
authors.initials: M
authors.lastname: Mine
authors.forename: M
authors.initials: M
authors.lastname: Imanaka
authors.forename: S
authors.initials: S
authors.lastname: Ogita
mesh_terms: D001826:Body Fluids / Q000502:physiology*; D001980:Bronchi / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005324:Fetal Movement; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012016:Reference Values; D012119:Respiration; D012212:Rheology; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal