title: PP055. Uric acid correlates with uterine artery vascular resistance, but not with uterine artery pulsatility index.
abstract: BACKGROUND
  Studies indicate that uric acid is involved in the development of hypertensive diseases of pregnancy, and that uric acid might influence the remodeling of the spiral arteries.
  
  
  OBJECTIVE
  To investigate the relationship with uric acid and utero-placental hemodynamics in the second half of pregnancy.
  
  
  METHODS
  53 women with uncomplicated pregnancies were examined longitudinally at 4-weekly intervals from 22 to 40 weeks of gestation. Blood samples for plasma uric acid were analyzed (enzymatic colorimetric method.
  
  
  METHODS
  Modular P, Roche Diagnostic), and blood pressure (BP) was measured. Uterine artery Doppler velocity waveforms were obtained, and vessel diameter was measured bilaterally. Uterine artery volume blood flow (Quta) was calculated as the product of mean velocity and cross-sectional area of the vessel. Mean arterial pressure (MAP) was calculated as: diastolic BP+(systolic BP - diastolic BP)/3. Uterine artery resistance (Rquta) was calculated as: MAP/Quta. Uterine artery pulsatility index (UtaPI) was calculated as: (peak systolic velocity - end-diastolic velocity)/time-averaged maximum velocity. Linear mixed models and linear regression models were used for statistical analysis.
  
  
  RESULTS
  242 blood samples were analyzed. Uric acid increased from 176 to 238μmol/L. Rquta and UtaPI decreased from 0.26 to 0.13mmHg/ml/min and 0.8-0.6 respectively. Uric acid was significantly correlated to Rquta (p=0.005), but not to Uta PI (p=0.178).
  
  
  CONCLUSIONS
  There is a strong association between uric acid and uterine artery vascular resistance during the second half of pregnancy indicating that uric acid might play a role in establishing low resistance blood flow in the uteroplacental compartment.
authors.forename: Kari
authors.initials: K
authors.lastname: Flo
authors.forename: Åse
authors.initials: Å
authors.lastname: Vårtun
authors.forename: Tom
authors.initials: T
authors.lastname: Wilsgaard
authors.forename: Ganesh
authors.initials: G
authors.lastname: Acharya