title: Doppler-velocity waveforms in ductus venosus in normal and small-for-gestational-age fetuses.
abstract: OBJECTIVE
  To investigate blood-flow patterns in ductus venosus in growth-retarded fetuses.
  
  
  METHODS
  Reference ranges of ductus venosus flow velocities were constructed from a cross-sectional study of 179 normal fetuses between 16 to 38 weeks' gestation. and the ductus venosus flow-velocity waveforms in 11 small-for-gestational-age (SGA) fetuses were compared with normal patterns.
  
  
  RESULTS
  Of 179 pregnant women who were possible subjects, 175 were employed for the analysis, and ductus venosus flow-velocity waveforms were obtained in 197 out of 211 examinations (success rate = 93.4%). The peak forward velocities during (a) ventricular systoles, (b) the lowest forward velocities during atrial contractions, and (c) the time-averaged velocities all linearly increased as gestational ages increased [respectively: (a) slope, 1.135; constant, 31.720; (b) slope, 1.154; constant, 1.557; (c) slope, 1.240; constant, 19.386]. Peak forward velocities during ventricular systoles and time-averaged velocities in the SGA group did not differ from those of the normal group. Three SGA fetuses with abnormal flow in the umbilical artery showed a marked reduction of the lowest velocities during atrial contractions in the ductus venosus, and two of them showed no forward velocity at all.
  
  
  CONCLUSIONS
  The Doppler-velocity waveforms of ductus venosus showed a marked reduction of the end diastolic flow, especially in SGA fetuses with abnormal umbilical artery flows.
authors.affiliation: Department of Obstertrics and Gynecology, Yamaguchi University School of Medicine, Ube, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakata
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D014463:Ultrasonography; D014680:Veins / Q000000981:diagnostic imaging* / Q000196:embryology* / Q000503:physiopathology