Sequential studies on components of the haemostatic mechanism in pregnancy with particular reference to the development of pre-eclampsia.

Components of the haemostatic mechanism were studied at intervals in 60 primigravidae over the course of pregnancy and the puerperium; 12 of these developed pre-eclampsia. During pregnancy there was a fall in fibrinolytic activity and fibrinolytic capacity and a rise in fibrinogen, FR-antigen, alpha 1-antitrypsin and alpha 2-macroglobulin. The women who subsequently developed pre-eclampsia could not be identified on the basis of these measurements. Following delivery there was a more rapid return of fibrinolytic activity and capacity towards normal in the women who had not had pre-eclampsia. The urinary FR-antigen level was higher in the women with pre-eclampsia.