Studies on coagulation and fibrinolysis in blood from puerperal women with and without oestrogen treatment.

Coagulation and fibrinolytic studies were made on 25 women who had a normal puerperium and breast fed their babies and on 32 otherwise healthy women who had lactation suppressed by diethylstilboestrol. In the untreated patients the fibrinogen, Factors VIII and IX, platelet count, and antifibrinolytic activity increased, and the levels of Factors II, VII, and X and of plasminogen and plasminogen proactivator decreased. The incidence of cold activation of Factor VII decreased slowly from the 5th postpartum day onwards. The concentration of antithrombin III which was depressed in pregnancy, increased in the puerperium and was the only observed change that counteracted an increased coagulation potential. Oestrogen treatment produced further increases of Factors II, VII, and X, platelet count, and the cold activation of Factor VII while it decreased the concentration of antithrombin III. These changes favoured coagulation but were possibly to some degree counterbalanced by an increased concentration of plasminogen and decreased antifibrinolytic activity.