title: Blood flow velocities in human intraplacental arteries.
abstract: OBJECTIVE
  To characterise the physiological findings of blood circulation in intraplacental arteries in normal and complicated pregnancies.
  
  
  METHODS
  A descriptive cross-sectional study. Umbilical and intraplacental artery resistance index (RI) Doppler recordings during the last trimester of pregnancy.
  
  
  METHODS
  Forty-nine normal pregnancies and ten pregnancies complicated by fetal growth retardation.
  
  
  RESULTS
  RI values decreased from the proximal umbilical artery to the distal umbilical artery and to intraplacental arteries. All of these vessels had decreasing RI values towards the end of pregnancy. In pathological pregnancies an abnormal flow pattern in umbilical arteries could be associated with either an abnormal or normal flow pattern in the intraplacental arteries.
  
  
  CONCLUSIONS
  Blood flow in intraplacental arteries can be recorded by sensitive color Doppler in normal pregnancies, but in complicated pregnancies variation of the Doppler findings, together with imaging difficulties of intraplacental arteries, seem to impair the applicability of this examination as a diagnostic tool.
authors.affiliation: Department of Obstetrics, University Hospital of Zũrich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Kirkinen
authors.forename: J
authors.initials: J
authors.lastname: Kurmanavichius
authors.forename: A
authors.initials: A
authors.lastname: Huch
authors.forename: R
authors.initials: R
authors.lastname: Huch
mesh_terms: D000328:Adult; D001775:Blood Circulation; D001783:Blood Flow Velocity; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000209:etiology; D010920:Placenta / Q000098:blood supply* / Q000000981:diagnostic imaging; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000502:physiology