Changes in blood coagulation and fibrinolysis during the puerperium

Abstract

During the puerperium an increased incidence of thromboembolic complications is observed. However, the incidence during pregnancy is relatively low. It is therefore of interest to study the changes in blood coagulation and fibrinolysis in connection with delivery because these changes may be one of the factors which predispose to thrombosis. This work shows that one to 4 weeks before delivery, there was a significantly increased level of fibrinogen, Factor II, VII, and X activities (P&P test), Factor VIII, and plasminogen. The urokinase excretion in the urine was significantly diminished during this period. The first days after delivery, a rapid decrease in the number of platelets and in the level of fibrinogen, Factor VIII, and plasminogen was observed. During the same period, there was an increase in the antifibrinolytic activity and also a pronounced increase in the urokinase excretion. Later during the puerperium, a new increase in fibrinogen, plasminogen, and, in some cases, in Factor VIII occurred before normal values were reached about 2 weeks post partum. Principally, the changes which were seen in the hemostatic mechanism during the puerperium were the same as those observed after extensive surgery. The significance of the changes in blood coagulation and fibrinolysis during the puerperium as related to thrombosis is discussed.