title: Tissue factor-dependent thrombin generation across pregnancy.
abstract: OBJECTIVE
  Normal pregnancy results in a prothrombotic state. Studies that have investigated the capacity of pregnant women to generate thrombin are limited. Our aim was to evaluate thrombin generation longitudinally from the preconception period, through pregnancy, and after pregnancy.
  
  
  METHODS
  We evaluated young, healthy nulligravid women (n = 20) at 4 time points and compared the data with 10 control women at 2 time points. Coagulation was initiated with tissue factor in contact pathway inhibited plasma, and thrombin generation was determined in the presence of a fluorogenic substrate.
  
  
  RESULTS
  The maximum level and rate of thrombin generation increased during pregnancy; the highest level and rate occurred in late pregnancy compared with prepregnancy (P < .001). Subsequently, thrombin generation decreased in the postpregnancy samples that included maximum level, rate, and area under the curve (P < .001).
  
  
  CONCLUSIONS
  Our data provide evidence for an increase in tissue factor-dependent thrombin generation with pregnancy progression, followed by a return to prepregnancy thrombin levels.
authors: Department of Obstetrics, Gynecology, and Reproductive Sciences, Fletcher Allen Health Care/University of Vermont, Burlington, USA.
authors: Kelley C
authors: KC
authors: McLean
authors: Ira M
authors: IM
authors: Bernstein
authors: Kathleen E
authors: KE
authors: Brummel-Ziedins
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000032:analysis; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D010976:Platelet Count; D049590:Postpartum Period / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D013917:Thrombin / Q000032:analysis* / Q000096:biosynthesis*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D006454:Hemoglobins; C036309:fibrin fragment D; D005340:Fibrinogen; D013917:Thrombin