title: Study of fetal tracheal fluid velocities using Doppler ultrasound.
abstract: OBJECTIVE
  To characterize tracheal fluid flow during fetal breathing movements by Doppler ultrasound.
  
  
  METHODS
  To use pulsed Doppler to measure flow velocity during inspiration and expiration in a cross-sectional study of 15 normal fetuses and determine the correlation, if any, between flow velocity and gestational age.
  
  
  RESULTS
  Cyclic respiratory profiles - both regular and irregular - were observed. Intratracheal flow velocity was very elevated during inspiration, ranging from 10 to 80 cm/s and from 5 to 20 cm/s during expiration.
  
  
  CONCLUSIONS
  This technique enables the noninvasive semiquantitative evaluation of fetal breathing movements. This Doppler application opens the field for future studies to characterize the extent of pulmonary hypoplasia.
authors.affiliation: Maternité Port-Royal, Groupe Hospitalier Cochin Saint Vincent De Paul, APHP, Université Paris Descartes, Fondation PremUp, Paris, France. gilles.grange@cch.aphp.fr
authors.forename: Gilles
authors.initials: G
authors.lastname: Grangé
authors.forename: Céline
authors.initials: C
authors.lastname: Bernabé-Dupont
authors.forename: Dominique
authors.initials: D
authors.lastname: Cabrol
mesh_terms: D000328:Adult; D001826:Body Fluids / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D011247:Pregnancy; D014132:Trachea / Q000000981:diagnostic imaging*; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal; D055815:Young Adult