title: Pulsatility index of the middle cerebral artery in normal fetuses.
abstract: OBJECTIVE
  To establish the reference ranges of the middle cerebral artery pulsatility index (MCA PI) in normal fetuses between 20 and 37 weeks gestation.
  
  
  METHODS
  A descriptive study.
  
  
  METHODS
  Antenatal Care Clinic, Outpatient department, Faculty of Medicine, Srinagarind Hospital, Khon Kaen University.
  
  
  METHODS
  At least sixteen women of each gestational age with an uncomplicated singleton pregnancy between 20 and 37 weeks gestation.
  
  
  METHODS
  All recruited pregnant women were enrolled for abdominal Doppler ultrasonography to determine fetal MCA PI for each week of gestational age.
  
  
  METHODS
  The MCA PI reference range for normal fetuses between 20 and 37 completed weeks of gestation.
  
  
  RESULTS
  The MCA PI decreased as gestational age advanced from 1.97 (SD 0.48) at 20 weeks to 1.15 (SD 0.18) at 37 weeks.
  
  
  CONCLUSIONS
  We established the reference ranges of the fetal MCA PI for reference use in our Antenatal Care Clinic.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Ratana
authors.initials: R
authors.lastname: Komwilaisak
authors.forename: Piyamas
authors.initials: P
authors.lastname: Saksiriwuttho
authors.forename: Thawalwong
authors.initials: T
authors.lastname: Ratanasiri
authors.forename: Pilaiwan
authors.initials: P
authors.lastname: Kleebkaow
authors.forename: Kanok
authors.initials: K
authors.lastname: Seejorn
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011674:Pulse; D012016:Reference Values; D013785:Thailand; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D055815:Young Adult