title: Prostacyclin, thromboxane A and the effect of low-dose ASA in pregnancies at high risk for hypertensive disorders.
abstract: BACKGROUND
  The aim of this study was to investigate the prostanoid production in pregnancies at high risk for hypertensive disorders, and the effect of low-dose acetylsalicylic acid (ASA) on prostanoids.
  
  
  METHODS
  Ninety women with a bilateral notching in uterine arteries screened by Doppler ultrasound at 12-14 gestational weeks were randomized to the ASA (0.5 mg/kg/day) or placebo group. Forty-three women in both groups were followed up throughout the pregnancy. Urine samples were taken at baseline, and at 24-26 and 32-34 weeks of gestation to determine the urinary 11-dehydrothromboxane B(2) (u-11-dehydro-TxB(2)) and 2,3-dinor-6-keto-prostaglandin F(1alpha) (u-2,3-dinor-6-keto-PGF(1alpha)), the metabolites of thromboxane A(2) and prostacyclin, respectively.
  
  
  RESULTS
  In the pregnancies with pregnancy-induced hypertension (PIH) before 37 gestational weeks, the 2,3-dinor-6-keto-PGF(1alpha)/11-dehydro-TxB(2) ratio did not increase as much as in other pregnancies (P = 0.028). In the placebo group pregnancies with preeclampsia had significantly lower 2,3-dinor-6-keto-PGF(1alpha) (P = 0.019) at 12-14 weeks of gestation compared to other pregnancies. In the placebo group the 2,3-dinor-6-keto-PGF(1alpha)/11-dehydroTxB(2) ratio remained unchanged throughout the pregnancy, with no significant difference between pregnancies with a normal or an adverse outcome. In the ASA group the 2,3-dinor-6-keto-PGF(1alpha)/11-dehydro-TxB(2) ratio increased (P < 0.001, early vs. midpregnancy). Again, the changes were similar in pregnancies with a normal or an adverse outcome.
  
  
  CONCLUSIONS
  The balance of prostacyclin and thromboxane A(2) shifted in an unfavorable direction in pregnancies complicated by PIH. ASA had a favorable effect on the prostanoids.
authors.affiliation: Department of Obstetrics and Gynecology, Hyvinkää Hospital, Hyvinkää, Finland. merja.vainio@hus.fi
authors.forename: Merja
authors.initials: M
authors.lastname: Vainio
authors.forename: Asko
authors.initials: A
authors.lastname: Riutta
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Koivisto
authors.forename: Johanna
authors.initials: J
authors.lastname: Mäenpää
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000031:analogs & derivatives* / Q000652:urine; D001241:Aspirin / Q000008:administration & dosage*; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage*; D011464:Epoprostenol / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000188:drug therapy* / Q000652:urine; D008137:Longitudinal Studies; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000188:drug therapy* / Q000652:urine; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011453:Prostaglandins / Q000378:metabolism; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine
chemical_list: D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D013929:Thromboxane B2; D013928:Thromboxane A2; D015121:6-Ketoprostaglandin F1 alpha; C028290:2,3-dinor-6-ketoprostaglandin F1alpha; C049235:11-dehydro-thromboxane B2; D011464:Epoprostenol; D001241:Aspirin