title: Maternal serum uric acid levels in twin gestations.
abstract: OBJECTIVE
  To establish normative values of serum uric acid levels in women with twin gestations and to compare maternal serum uric acid levels of twins and singletons, stratified by the presence or absence of preeclampsia.
  
  
  METHODS
  Sixty-seven normotensive and 16 preeclamptic women with twin gestations, who had no underlying chronic hypertension or renal insufficiency, had serum uric acid levels measured on admission to the labor and delivery unit. These levels were compared with those of 83 normotensive and 10 preeclamptic singleton gravidas admitted to the same unit. A receiver operating characteristic (ROC) curve was used to determine the optimal maternal serum uric acid cutoff value for twin gestations and to compare this value with that of singleton gestations.
  
  
  RESULTS
  Women with non-preeclamptic twin pregnancies had significantly higher mean (+/- standard deviation) serum uric acid concentration than women with non-preeclamptic singleton pregnancies (5.4 +/- 1.6 versus 4.7 +/- 1.2 mg/dL, respectively, P = .001). Gravidas with twin gestations complicated by preeclampsia had significantly higher serum uric acid levels than their preeclamptic singleton counterparts (7.7 +/- 1.3 versus 5.9 +/- 1.1 mg/dL, respectively, P = .001). Using a ROC curve, we determined that a maternal serum uric acid level of 6.5 mg/dL appeared to be the optimal cutoff for identifying preeclampsia in twin gestations, with a sensitivity of 94% and specificity of 78%.
  
  
  CONCLUSIONS
  With or without preeclampsia, women carrying twins have significantly higher serum uric acid levels than their singleton counterparts, which suggests a need for separate normative values for twin gestations. We propose that a serum uric acid level of 6.5 mg/dL or greater be used to identify those women with twin gestations who are at higher risk for preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden, Cooper Hospital/University Medical Center, New Jersey.
authors.forename: R L
authors.initials: RL
authors.lastname: Fischer
authors.forename: K W
authors.initials: KW
authors.lastname: Bianculli
authors.forename: M L
authors.initials: ML
authors.lastname: Hediger
authors.forename: T O
authors.initials: TO
authors.lastname: Scholl
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D011225:Pre-Eclampsia / Q000097:blood* / Q000209:etiology; D011247:Pregnancy / Q000097:blood*; D011272:Pregnancy, Multiple / Q000097:blood*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014427:Twins; D014527:Uric Acid / Q000097:blood*
chemical_list: D015415:Biomarkers; D014527:Uric Acid