title: Doppler study of the fetal middle cerebral artery at three locations: preliminary report.
abstract: BACKGROUND
  Middle cerebral artery (MCA) detection is useful in monitoring fetal well-being. Knowledge of Doppler flow velocity of the fetal MCA may assist in prenatal diagnosis and management of complicated pregnancies. The aim of this study was to compare the pulsatility index (PI) and resistance index (RI) of the MCA at different locations throughout pregnancy.
  
  
  METHODS
  Uncomplicated singleton pregnancies accepted Doppler surveys of the bilateral MCA. PI and RI values of the proximal, middle, and distal 1/3 of the MCA were measured. The gestation periods for Doppler surveys were (1) 15 to 19 weeks; (2) 20 to 24 weeks; (3) 25 to 29 weeks; (4) 30 to 34 weeks; and (5) 35 to 40 weeks. The MCA flows at different locations and at different gestational aged were compared.
  
  
  RESULTS
  There were 21 patients included. Average PI/RI values of the proximal, middle and distal MCA were 1.62/0.80, 1.69/0.81, and 1.71/0.83, which were non-significantly different. The PI/RI values of MCA in each gestational phase were also non-significantly different: (1) 1.70/0.84; (2) 1.72/0.82; (3) 1.68/0.83; (4) 1.65/0.81; (5) 1.62/0.77.
  
  
  CONCLUSIONS
  The PI and RI values of the proximal MCA were non-significantly lower than those of middle and distal MCA. Middle MCA could represent three locations of MCA. A trend of lower PI/RI values with advancing gestation was noted.
authors.affiliation: Department of Obstetrics and Gynecology, China Medical College Hospital, Taichung, Taiwan.
authors.forename: C C
authors.initials: CC
authors.lastname: Chang
authors.forename: Y Y
authors.initials: YY
authors.lastname: Hsieh
authors.forename: H D
authors.initials: HD
authors.lastname: Tsai
mesh_terms: D000328:Adult; D005260:Female; D005323:Fetal Monitoring; D006801:Humans; D017078:Laser-Doppler Flowmetry; D020768:Middle Cerebral Artery / Q000502:physiology*; D011247:Pregnancy; D014655:Vascular Resistance