title: Comparison of different reference values of fetal blood flow velocity in the middle cerebral artery for predicting fetal anemia.
abstract: OBJECTIVE
  To compare different normal reference ranges of fetal blood flow velocity in the middle cerebral artery for predicting fetal anemia.
  
  
  METHODS
  Eight reference ranges of either middle cerebral artery peak or time-averaged mean velocities were compared using the area under the receiver-operating characteristics (ROC) curve for 113 fetal blood samples from 60 women at risk of fetal red blood cell alloimmunization.
  
  
  RESULTS
  The areas under the ROC curves of the different ranges were not significantly different but there were marked differences in sensitivity (range, 7.14-91.78%) and specificity (range, 31.25-96.88%) with the currently used cut-offs. Except for Mari's range, the best theoretical cut-offs, defined as those having the best sensitivity with the best specificity, differed from those in current use, especially when using time-averaged mean velocity.
  
  
  CONCLUSIONS
  Any of the previously reported reference ranges perform well in the non-invasive prediction of fetal anemia. However, with the exception of Mari's curve, the currently employed cut-offs for predicting fetal anemia should be changed, some of them markedly, in order to provide reliable support for clinical decisions.
authors.affiliation: Fetal Medicine Unit, St Michael's Hospital, Bristol, UK. Joseluis.bartha@uca.es
authors.forename: J L
authors.initials: JL
authors.lastname: Bartha
authors.forename: S
authors.initials: S
authors.lastname: Illanes
authors.forename: S
authors.initials: S
authors.lastname: Abdel-Fattah
authors.forename: A
authors.initials: A
authors.lastname: Hunter
authors.forename: M
authors.initials: M
authors.lastname: Denbow
authors.forename: P W
authors.initials: PW
authors.lastname: Soothill
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D004899:Erythroblastosis, Fetal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005312:Fetal Blood / Q000502:physiology*; D005865:Gestational Age; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D020768:Middle Cerebral Artery / Q000196:embryology / Q000503:physiopathology*; D011247:Pregnancy; D012372:ROC Curve; D012016:Reference Values; D012189:Retrospective Studies; D012203:Rh Isoimmunization / Q000000981:diagnostic imaging / Q000503:physiopathology; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods; D016216:Ultrasonography, Prenatal / Q000379:methods
chemical_list: D006454:Hemoglobins