title: Short-term maternal oxygen administration in fetuses with absence or reversal of end-diastolic velocity in umbilical artery: pathophysiological and clinical considerations.
abstract: BACKGROUND
  The aim of our study was to evaluate the hemodynamic response to acute maternal hyperoxygenation (O2 test) in a group of growth retarded fetuses with absence or reversal of end-diastolic velocity (AREDV) in the umbilical artery (UA) and to correlate this response to a series of feto-placental velocimetric parameters and clinical variables.
  
  
  METHODS
  In 25 singleton pregnancies, feto-maternal Doppler velocimetry was performed before and after acute maternal hyperoxygenation.
  
  
  RESULTS
  Ten fetuses (40%) exhibited an increase of middle cerebral artery Pulsatility Index (PI) >20% after O2 (Responders), while in 15 fetuses PI did not change relevantly (Nonresponders). Non-responder fetuses showed a higher prevalence of reverse flow in umbilical artery (6/15 vs 0/10: p<0.03) and a slight, but not significant, higher percentage with reversed flow in inferior vena cava (% of A). Also the prevalence of a % of A greater than 95th confidence interval was higher in Non-responders (13/15 vs 4/10; p<0.04). Finally the Responder fetuses showed higher peak velocities in the cardiac outflows, even if the difference reached a statistical significance only for the pulmonary artery. The outcome of the two groups did not differ significantly.
  
  
  CONCLUSIONS
  Our results seem to prove an ability of O2 test in selecting a group of AREDV fetuses characterized by a higher degree of hemodynamic deterioration and hence 'placed' in a more advanced step of the pathological process leading to overt cardiac decompensation, even if the clinical application of such a test seems to be still of limited value.
authors.affiliation: Department of Obstetrics and Gynecology, Catholic University of Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Caforio
authors.forename: A
authors.initials: A
authors.lastname: Caruso
authors.forename: A C
authors.initials: AC
authors.lastname: Testa
authors.forename: A
authors.initials: A
authors.lastname: Pompei
authors.forename: M
authors.initials: M
authors.lastname: Ciampelli
mesh_terms: D001794:Blood Pressure; D003971:Diastole; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D006801:Humans; D010100:Oxygen / Q000008:administration & dosage*; D011247:Pregnancy; D012212:Rheology; D014469:Umbilical Arteries
chemical_list: D010100:Oxygen