title: Raised uterine artery impedance is associated with increased maternal arterial stiffness in the late second trimester.
abstract: OBJECTIVE
  To assess the relationship between uterine artery Doppler pulsatility index (PI) and maternal global arterial stiffness and aortic stiffness in women at high a priori risk of preeclampsia in the late second trimester of pregnancy.
  
  
  METHODS
  A prospective cohort study was performed. 99 women were recruited from the high-risk obstetric ultrasound clinic in the second trimester; median (±IQR) age and gestation were 33 (29-37) years and 23(+6) (23(+3)-24(+4)) weeks respectively. Transabdominal uterine artery Doppler was performed and mean values recorded. Women returned at a later date, median gestation (±IQR) 26(+5) (25(+6)-28(+0)) weeks, for measurement of blood pressure, augmentation index (AIx) and aortic pulse wave velocity (aPWV).
  
  
  RESULTS
  Uterine artery PI is positively associated with both AIx (r = 0.4, P <0.0001, 95% CI: 0.22-0.55) and aPWV (r = 0.22, P = 0.03, 95% CI: 0.02-0.40). No relationship was found between uterine artery PI and mean arterial pressure or pulse pressure. AIx was significantly higher in women with uterine artery PI > 1.45 (P = 0.003, 95% CI: 3.1-14.9) but not aPWV (P = 0.45). AIx, but not aPWV, was significantly higher in women who developed preeclampsia (14% vs 9%, 95% CI: 2.0-8.6, P = 0.0018) or IUGR (11% vs 9%, 95% CI: 0.3-4.2, P = 0.027). AIx showed a negative correlation with birth weight z-score (r = -0.25, 95% CI: -0.43 to -0.06, P = 0.013).
  
  
  CONCLUSIONS
  Increasing uterine artery Doppler PI reflects impaired placentation and increasing risk of preeclampsia. We show a positive association between uterine artery Doppler PI and both global arterial and aortic stiffness. We also show that increased maternal arterial stiffness is associated with a lower birth weight. These findings may represent evidence of an early effect of impaired placentation on the maternal vasculature. Alternatively, given the association between preeclampsia and later cardiovascular disease, ineffective placentation may result from impaired arterial function.
authors.affiliation: Department of Fetal Medicine, Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: T R
authors.initials: TR
authors.lastname: Everett
authors.forename: A A
authors.initials: AA
authors.lastname: Mahendru
authors.forename: C M
authors.initials: CM
authors.lastname: McEniery
authors.forename: I B
authors.initials: IB
authors.lastname: Wilkinson
authors.forename: C C
authors.initials: CC
authors.lastname: Lees
mesh_terms: D000328:Adult; D001724:Birth Weight; D001794:Blood Pressure; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D010929:Placentation / Q000502:physiology; D011225:Pre-Eclampsia / Q000175:diagnosis / Q000503:physiopathology*; D011247:Pregnancy; D018566:Pregnancy, High-Risk / Q000502:physiology*; D011446:Prospective Studies; D011673:Pulsatile Flow; D012307:Risk Factors; D014463:Ultrasonography; D055988:Uterine Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D059289:Vascular Stiffness / Q000502:physiology*