title: Doppler evaluation of the posterior cerebral artery in normally grown and growth restricted fetuses.
abstract: OBJECTIVE
  To evaluate Doppler parameters of the two segments of the posterior cerebral artery (PCA) in normally grown and growth restricted (IUGR) fetuses.
  
  
  METHODS
  Normal reference values of the pulsatility index (PI), peak systolic velocity, end-diastolic velocity, and time-averaged maximum velocity from the two segments of the PCA (segment one, PCA-S1; segment two, PCA-S2) were constructed in 350 pregnant women from 20 to 40 weeks of gestation. The association of the two PCA segments with the middle cerebral artery (MCA), and with the umbilical artery was evaluated in 50 IUGR fetuses.
  
  
  RESULTS
  In normal fetuses, Doppler parameters from PCA-S1 and PCA-S2 showed similar behavior throughout gestation. In IUGR fetuses, the PI of the two PCA segments was significantly reduced with no differences between them. PCA-S2 PI showed a higher correlation with the MCA-PI (r = 0.73) than PCA-S1 PI (r = 0.63; p = 0.001). IUGR fetuses showed vasodilatation in the PCA earlier than in the MCA disregarding the umbilical artery-PI value.
  
  
  CONCLUSIONS
  In IUGR fetuses, the two segments of the PCA show signs of vasodilatation earlier than the MCA. As IUGR fetuses deteriorate, the two segments of the PCA and the MCA behave similarly.
authors.affiliation: Fetal and Perinatal Medicine Research Group, Department of Maternal-Fetal Medicine, Hospital Clínic, Institut d'Investigacions Biomediques August Pi i Sunyer, University of Barcelona, Barcelona, Spain; Department of Obstetrics and Gynecology, Technological University of Pereira, Pereira, Colombia; National Institute of Perinatal Medicine (INPer) Mexico City, Mexico.
authors.forename: Jesus Andres
authors.initials: JA
authors.lastname: Benavides-Serralde
authors.forename: Edgar
authors.initials: E
authors.lastname: Hernandez-Andrade
authors.forename: Rogelio
authors.initials: R
authors.lastname: Cruz-Martinez
authors.forename: Mónica
authors.initials: M
authors.lastname: Cruz-Lemini
authors.forename: Matthias
authors.initials: M
authors.lastname: Scheier
authors.forename: Francesc
authors.initials: F
authors.lastname: Figueras
authors.forename: Javier
authors.initials: J
authors.lastname: Mancilla
authors.forename: Eduard
authors.initials: E
authors.lastname: Gratacos
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging*; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011673:Pulsatile Flow; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*; D055815:Young Adult