title: Fibrin generation in normal pregnancy.
abstract: Both clinical and laboratory findings suggest that pregnancy constitutes a hypercoagulable condition; yet none of the observed laboratory changes are specific for thrombosis. An essential step involves thrombin-mediated fibrin generation. In the process, fibrinopeptide A (FPA) is cleaved from fibrinogen. Using a radioimmune assay, FPA was determined prospectively in a longitudinal and cross-sectional fashion. Fibrinopeptide A increased significantly over control by the end of the first trimester, from 1.3 ng/ml to 2.8 ng/ml. It continued to increase until 30 to 32 weeks' gestation and then plateaued at 4.3 to 4.7 ng/ml. In the immediate postpartum period, FPA remains elevated. In conclusion, thrombin generation as reflected in FPA production is increased throughout pregnancy, thus confirming a hypercoagulable milieu.
mesh_terms: D005260:Female; D005337:Fibrin / Q000096:biosynthesis*; D005340:Fibrinogen / Q000097:blood*; D005344:Fibrinopeptide A / Q000097:blood*; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D011863:Radioimmunoassay
chemical_list: D005344:Fibrinopeptide A; D005337:Fibrin; D005340:Fibrinogen