Pregnancy fibrinogen

S., and Degen, J. L. (1995). Resolution of spontaneous bleeding events but failure of pregnancy in fibrinogen-deficient mice. Genes Develop. 9, 2020-2033. 

Two neonates born of mothers who had taken valproate during pregnancy developed bleeding associated with fibrinogen depletion soon after birth, and one of them died from afibrinogenemia (SEDA-19, 75). 

Factor VIII levels up to 4 times normal have been reported at term (P5, S3, T3). Some other clotting factors also rise in concentration during pregnancy, for instance fibrinogen (16, M3, P5), factor VII (LI, Nl), and factor X (PI), but apparently not prothrombin (Dl). The significance of this pattern of changes is not known. 

In pregnancy, diabetes, and chronic inflammatory states there is a sustained rise in factor VIII concentration, accompanied by increases in other clotting factors, of which fibrinogen is the most constant and probably the most closely correlated quantitatively. In diabetes and atherosclerotic disease there is also an increase in the bleeding-time factor. Similar effects on the clotting factors can be produced by applying stresses which operate over a few days, such as the intramuscular injection of the subject s own blood. The rate of increase in factor VIII concentration indicated by serial assays is not more rapid than may be seen in patients with von Willebrand s disease after infusion of hemophilic plasma, and may therefore be reasonably ascribed to an increased rate of synthesis, since there is... 

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