title: Nomogram of fetal middle cerebral artery peak systolic velocity at 23-35 weeks of gestation in a Brazilian population: pilot study.
abstract: OBJECTIVE
  To establish normative data for the peak systolic velocity of the middle cerebral artery (MCA-PSV) of fetuses in the second half of pregnancy using multiples of the median and percentile reference range.
  
  
  METHODS
  A cross-sectional study was performed in 90 healthy fetuses at between 23 and 35 weeks of gestation. A bi-dimensional axial scan of the brain, including the thalami and cavitas septi pellucidi was obtained. The circle of Willis was visualized using color flow mapping. Pulsed-wave Doppler velocimetry of the MCA was performed close to the artery's origin, with a beam-vessel angle below 20 degrees . A table with the multiples of the median (MoM) of the MCA-PSV for each gestational age was generated and Pearson's correlation coefficient (r) was calculated. Regression modeling across gestational age was performed to obtain the reference values.
  
  
  RESULTS
  There was a strong correlation between the MCA-PVS and gestational age (r = 0.70; p < 0.001). Values for the MCA-PSV for the following MoM were calculated: 1.0, 1.29, 1.50, and 1.55. The MCA-PSV 2.5(th) and 97.5(th) centiles ranged from 24.33 cm(2)/s to 78.36 cm(2)/s, respectively, between weeks 23 and 35.
  
  
  CONCLUSIONS
  A nomogram for the fetal MCA-PSV during the second half of pregnancy was generated.
authors.affiliation: Obstetrics Department, Sao Paulo Federal University (UNIFESP-EPM), Sao Paulo, SP, Brazil. unardozza@uol.com.br
authors.forename: Luciano Marcondes Machado
authors.initials: LM
authors.lastname: Nardozza
authors.forename: Christiane
authors.initials: C
authors.lastname: Simioni
authors.forename: Gabriel
authors.initials: G
authors.lastname: Garbato
authors.forename: Edward
authors.initials: E
authors.lastname: Araujo Júnior
authors.forename: Helio Antonio
authors.initials: HA
authors.lastname: Guimarães Filho
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Torloni
authors.forename: Luiz
authors.initials: L
authors.lastname: Camano
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: Moron
mesh_terms: D001783:Blood Flow Velocity; D001938:Brazil; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D049451:Nomograms; D010865:Pilot Projects; D011153:Population; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000502:physiology*; D011263:Pregnancy Trimester, Third / Q000502:physiology*; D016216:Ultrasonography, Prenatal / Q000379:methods / Q000706:statistics & numerical data*