title: Prostacyclin/thromboxane early changes in pregnancies that are complicated by preeclampsia.
abstract: OBJECTIVE
  The purpose of this study was to examine 6-keto-prostaglandin F(1)(alpha) and thromboxane B(2) plasma levels throughout normotensive and preeclamptic pregnancies and to analyze the predictive values of these quantifications for the detection of preeclampsia during the second trimester of pregnancy.
  
  
  METHODS
  Blood samples were collected from 30 healthy, nonpregnant women and at 4-week intervals from a cohort of nulliparous women who were recruited before 16 weeks of gestation. Preeclampsia developed in 26 patients; 52 normotensive control subjects were matched from the same cohort. The 6-keto-prostaglandin F(1)(alpha) and thromboxane B(2) were assayed by radioimmunoassay. Trends were compared between pregnancy groups and with the nonpregnant women. Predictive values were determined with the second-trimester assessments.
  
  
  RESULTS
  The 6-keto-prostaglandin F(1)(alpha)/thromboxane B(2) ratio decreased throughout pregnancy in women with preeclampsia; there were no significant changes in normotensive women. We found higher thromboxane B(2) levels within the group with preeclampsia during the first gestational trimester (preeclampsia, 188 +/- 17 pg/mL; control, 119 +/- 4.8 pg/mL [mean +/- SEM]; P =.001). During the third trimester, patients with preeclampsia had lower 6-keto-prostaglandin F(1)(alpha) levels than did control subjects (preeclampsia, 191 +/- 9.8 pg/mL; control, 288 +/- 10 pg/mL; P =.001). The 6-keto-prostaglandin F(1)(alpha)/thromboxane B(2) ratio was suitable to calculate predictive values; the best cutoff point and time interval were 3.0 and 22 to 26 weeks of gestation, respectively. Sensitivity, specificity, and positive and negative predictive values were 88%, 97%, 69%, and 99%, respectively; the odds ratio was 14.6 (95% CI, 6.9-30.4).
  
  
  CONCLUSIONS
  The prostacyclin/thromboxane ratio favored vasoconstriction early in gestation in women in whom preeclampsia developed. A 6-keto-prostaglandin F(1)(alpha)/thromboxane B(2) ratio of <or=3.0 at 22 to 26 weeks of gestation had a high predictive value for the development of preeclampsia.
authors.affiliation: Medical Research Unit in Reproductive Medicine, Luis Castelazo-Ayala Gynecology and Obstetrics Hospital, Mexico City, Mexico. drareyes@prodigy.net.mx
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Chavarría
authors.forename: Lina
authors.initials: L
authors.lastname: Lara-González
authors.forename: Alejandro
authors.initials: A
authors.lastname: González-Gleason
authors.forename: Yolanda
authors.initials: Y
authors.lastname: García-Paleta
authors.forename: Víctor Saúl
authors.initials: VS
authors.lastname: Vital-Reyes
authors.forename: Alejandro
authors.initials: A
authors.lastname: Reyes
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood*; D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000097:blood*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012016:Reference Values; D012680:Sensitivity and Specificity; D013929:Thromboxane B2 / Q000097:blood*
chemical_list: D015415:Biomarkers; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha