title: Reference values for Doppler parameters of the fetal anterior cerebral artery throughout gestation.
abstract: OBJECTIVE
  To construct normal reference values for Doppler parameters in 2 anatomical segments of the fetal anterior cerebral artery (ACA) throughout pregnancy.
  
  
  METHODS
  The ACA was evaluated in 373 normally growing fetuses from 20 to 40 weeks of gestation. The first segment of the ACA (ACA-S1) was recorded just after its origin from the internal carotid artery in the same plane as the middle cerebral artery (MCA). The second segment (ACA-S2) was recorded distal to the outlet of the anterior communicating artery.
  
  
  RESULTS
  The ACA pulsatility index (PI) behaved similarly in both segments, with a constant increase until 28 weeks followed by a decrease until the end of pregnancy [ACA-S1 PI = 3.49 - 0.37 x gestational age (GA) - (0.0063 x GA(2)), SD = 0.6 - 0.061 x GA - (0.001 x GA(2)); ACA-S2 PI = 1.54 - 0.22 x GA - (0.0037 x GA(2)), SD = 0.206 + (0.0037 x GA)]. Peak systolic velocities in both segments showed a constant increase from 20 to 40 weeks of gestation. No significant differences were found between the 2 segments with regard to any Doppler parameter. However, the angle of insonation and the time spent on examination were significantly lower and reproducibility was better for ACA-S1.
  
  
  CONCLUSIONS
  Despite showing similar Doppler values, ACA-S1 has a higher reliability than ACA-S2 and can be recorded in the same anatomical projection as the MCA.
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.
authors.forename: J A
authors.initials: JA
authors.lastname: Benavides-Serralde
authors.forename: E
authors.initials: E
authors.lastname: Hernández-Andrade
authors.forename: H
authors.initials: H
authors.lastname: Figueroa-Diesel
authors.forename: D
authors.initials: D
authors.lastname: Oros
authors.forename: L A
authors.initials: LA
authors.lastname: Feria
authors.forename: M
authors.initials: M
authors.lastname: Scheier
authors.forename: F
authors.initials: F
authors.lastname: Figueras
authors.forename: E
authors.initials: E
authors.lastname: Gratacós
mesh_terms: D000293:Adolescent; D000328:Adult; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging*; D001921:Brain / Q000098:blood supply*; D003430:Cross-Sectional Studies; D005260:Female; D005333:Fetus / Q000033:anatomy & histology* / Q000098:blood supply; D005865:Gestational Age; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011247:Pregnancy; D012016:Reference Values; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color / Q000379:methods* / Q000592:standards; D055815:Young Adult