The effects of stilboestrol and quinestrol upon coagulation and fibrinolysis during the puerperium.

Two oestrogens, stilboestrol and quinestrol, were used to inhibit lactation and their effects upon coagulation and fibrinolysis were compared with control patients before delivery, during the puerperium and six weeks after delivery. During the first week of the puerperium, stilboestrol therapy was associated with rises of factors IX and X and quinestrol therapy with rises of factors IX and II. Six weeks after delivery, the clotting factors were similar to the control values in those who had received stilboestrol but factor II was still raised in the quinestrol treated patients. Additionally, a significant rise of factor X in the quinestrol group was noted at this time. Plasma antithrombin levels rose during the first week of the puerperium in all three groups but, six weeks after delivery, they were lower in those who had received oestrogens. Stilboestrol and quinestrol were also associated with a rise of plasminogen and antiplasmin concentration during the first week of the puerperium. Six weeks after delivery, quinestrol treated patients still had raised levels of plasminogen and antiplasmin while the stilboestrol treated patients only had raised levels of antiplasmin. These changes in coagulation and fibrinolysis are similar to those reported during oral contraceptive therapy. The persisting changes six weeks after delivery in women who had taken quinestrol might indicate an increased thrombogenic risk when long acting oestrogen preparations are used to inhibit lactation.