Physiological correction of hereditary mild hypofibrinogenemia during pregnancy

IntroductionHereditary hypofibrinogenemia is a rare fibrinogen disorder characterised by decreased levels of fibrinogen. Pregnant women with hypofibrinogenemia are at risk of adverse obstetrical outcomes, depending on the fibrinogen level. AimWe investigated how the physiological changes of hemostasis throughout the pregnancy impact the hemostatic balance in a woman with hereditary mild hypofibrinogenemia. MethodsFibrin clot properties were analyzed by turbidimetry and scanning electron microscopy, clot weight and red blood cells retention were measured by whole clot contraction, and in vitro thrombin generation was assessed by calibrated automated thrombogram and ex vivo by TAT. ResultsThroughout the pregnancy, the fibrinogen levels increased reaching normal values in the third trimester (activity 3.1 g/L, antigen 3.2 g/L). In parallel, the fibrin polymerisation increased, the fibrinolysis decreased, the fibrin clot network became denser with thicker fibrin fibers, and the fibrin clot weight and red blood cells retention increased, reaching control's value at the third trimester. Similarly, in vitro and ex vitro thrombin generation increased, reaching maximum values at the delivery. ConclusionIn this case of hereditary mild hypofibrinogenemia we observed a physiological increase of fibrinogen and thrombin generation. Future studies should focus on moderate and severe hypofibrinogenemia, to assess fibrinogen variation and the overall impact of increased TG on the hemostasis balance.

Automated summary

This study investigated the impact of pregnancy on the hemostatic balance in a woman with hereditary mild hypofibrinogenemia. The results showed that fibrinogen levels increased, fibrin polymerisation increased, fibrinolysis decreased, the fibrin clot network became denser with thicker fibrin fibers, and thrombin generation increased during pregnancy. This study reveals the physiological changes in the hemostatic system of pregnant women with hereditary mild hypofibrinogenemia.