title: Volumetric flow in the umbilical artery: normative data.
abstract: OBJECTIVE
  Provide normative data for the volumetric blood flow (cc/min and cc/min/kg) in the umbilical artery.
  
  
  METHODS
  Flow was determined from an umbilical artery in 252 normal obstetrical patients from 18-40 weeks' gestation utilizing pulsed Doppler and color flow Doppler with an angle of insonation of 30-60 degrees. Simultaneous velocimetry studies (S/D ratio, resistance and pulsatility indices), fetal biometry, and an anatomic survey were obtained to further define the normal population.
  
  
  RESULTS
  There was a steady increase in the flow (cc/min) in the umbilical artery as pregnancy progressed. Flow/kg showed a steady decline as fetal weight increased. Umbilical artery diameter increased until reaching a plateau at 32-34 weeks. Velocimetric results were consistent with known data.
  
  
  CONCLUSIONS
  Volumetric blood flow in the umbilical artery can be determined with relative ease and normative data from 18-40 weeks is presented for the first time.
authors.affiliation: Department of Obstetrics and Gynecology, Memorial Health University Medical Center, Savannah, Georgia 31403-3089, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Goldkrand
authors.forename: D H
authors.initials: DH
authors.lastname: Moore
authors.forename: S U
authors.initials: SU
authors.lastname: Lentz
authors.forename: S P
authors.initials: SP
authors.lastname: Clements
authors.forename: A D
authors.initials: AD
authors.lastname: Turner
authors.forename: J L
authors.initials: JL
authors.lastname: Bryant
mesh_terms: D000328:Adult; D001810:Blood Volume / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D017078:Laser-Doppler Flowmetry; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy / Q000502:physiology*; D011673:Pulsatile Flow; D012016:Reference Values; D012039:Regional Blood Flow; D018615:Ultrasonography, Doppler, Color; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000502:physiology*