title: [Comparison study on uterine and umbilical artery blood flow during pregnancy at high altitude and at low altitude].
abstract: OBJECTIVE
  To evaluate the effect of high altitude on uterine and umbilical artery blood flow dynamics during normal pregnancy.
  
  
  METHODS
  Uterine artery blood flow parameters of the pregnant (34) and nonpregnant (37) subjects and umbilical artery blood flow parameters of 119 subjects living at high altitude or at low altitude were measured with color Doppler flow imaging system.
  
  
  RESULTS
  Uterine artery diameter, blood flow volume increased during pregnancy at both altitude, and uterine artery blood flow volume and diameter were smaller at high altitude than at low altitude [(0.35 +/- 0.04) cm vs (0.45 +/- 0.04) cm, (280 +/- 48) ml/min vs (425 +/- 55) ml/min, P < 0.01]. Umbilical artery blood flow velocity systolic to diastolic (S/D) value, resistant index of different pregnant period were greater at high altitude than at low altitude (P < 0.01).
  
  
  CONCLUSIONS
  High altitude has effect on placental and infant blood flow that causes the decrease of placental blood infusion and the increase of uterine and umbilical artery flow velocity S/D and reactive index.
authors.affiliation: Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Dingzhang
authors.initials: D
authors.lastname: Chen
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Zhu
authors.forename: Ting
authors.initials: T
authors.lastname: Zhu
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D000531:Altitude; D001783:Blood Flow Velocity; D002681:China; D005260:Female; D006801:Humans; D011247:Pregnancy; D018615:Ultrasonography, Doppler, Color; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D014599:Uterus / Q000098:blood supply*