title: Establishing reference intervals for D-dimer to trimesters.
abstract: OBJECTIVE
  When D-dimer is used to evaluate suspected venous thromboembolism in pregnant patients, the reference interval of common population may cause misinterpretation. The present study aims to determine reference intervals of D-dimer in the three trimesters.
  
  
  METHODS
  Four-hundred sixteen pregnant women and 32 non-pregnant women were enrolled in this cross-sectional study. Reference group had comprised 123 pregnant in the first trimester (5-11 week), 164 pregnant in the second trimester (13-20 week) and 126 pregnant women in the third trimester (25-35 week). D-dimer levels were analyzed via immunoturbidimetric assay.
  
  
  RESULTS
  If the threshold of 0.50 mg/L for diagnosis of VTE is used, 4.8% of pregnant women in the second trimester and 23.8% of pregnant women in the third trimester would have D-dimer levels exceeding this cut-off value. Reference intervals of D-dimer were determined as 0.11-0.40 mg/L; 0.14-0.75 mg/L and 0.16-1.3 mg/L in first, second and third trimester, respectively.
  
  
  CONCLUSIONS
  The established D-dimer reference intervals for each trimester of pregnancy are different from those used in common population. These reference intervals may assist clinicians in making accurate clinical decisions. Further studies are needed to establish new cut-off values for the D-dimer to rule out VTE in each trimester.
authors: Department of Clinical Biochemistry, Lüleburgaz State Hospital , Kırklareli , Turkey .
authors: Şerif
authors: Ş
authors: Ercan
authors: Sadullah
authors: S
authors: Özkan
authors: Nihal
authors: N
authors: Yücel
authors: Asuman
authors: A
authors: Orçun
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000097:blood*; D012016:Reference Values; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: D-dimer; pregnancy; reference interval; trimesters; venous thromboembolism