title: Fetal ophthalmic artery blood flow velocity waveforms.
abstract: OBJECTIVE
  To evaluate alterations in vascular impedance of the fetal ophthalmic artery (OA) with advancing gestation.
  
  
  METHODS
  Color Doppler flow imaging and pulsed Doppler ultrasonographic assessment were performed on 28 normal fetuses, at gestational ages ranging from 21 to 40 weeks. The pulsatility index (PI) was calculated for the OA and the middle cerebral artery (MCA). Optimal models for these PI values were determined by regression analysis. A normal range of PI values for both arteries was generated.
  
  
  RESULTS
  In the OA, the model showed a parabolic pattern during pregnancy, as was the case for MCA. The predicted PI values for the OA were always lower than those for the MCA.
  
  
  CONCLUSIONS
  Our study is the first to demonstrate alterations in regional vascular impedance of the fetal OA with advancing gestation. These data provide a foundation for the evaluation of fetal ocular circulation in normal and abnormal pregnancies.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka Gyohmeikan Hospital, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: T
authors.initials: T
authors.lastname: Hata
authors.forename: Y
authors.initials: Y
authors.lastname: Ariyuki
authors.forename: D
authors.initials: D
authors.lastname: Senoh
authors.forename: K
authors.initials: K
authors.lastname: Makihara
authors.forename: K
authors.initials: K
authors.lastname: Hata
authors.forename: M
authors.initials: M
authors.lastname: Kitao
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005865:Gestational Age; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging* / Q000196:embryology*; D011247:Pregnancy; D011673:Pulsatile Flow; D012044:Regression Analysis; D012212:Rheology; D018615:Ultrasonography, Doppler, Color