CHANGES IN THE COAGULATION AND FIBRINOLYTIC SYSTEM DURING PREGNANCY

Blood samples were collected from 17 volunteers between 8-14, 26-28 and 32-34 weeks of pregnancy. Control samples were collected from 12 non-pregnant female volunteers not using oral contraceptives. All samples were assayed for fibrinopeptide A (FPA), B beta 15-42 and for cross linked D-dimer fragments. A sample was collected for measurement of the in vitro rate of generation of fibrinopeptide A from whole blood (FPA-R). These results are consistent with an increased activation of coagulation (increased FPA and shortened FPA-R) during normal pregnancy, which is compensated for by a concomitant rise in fibrinolytic activity (increased D-dimer and B beta 15-42). In 2 patients who miscarried and 2 patients who developed hypertension during pregnancy changes indicative of a non compensated hypercoagulable state could be seen. The study shows that the progress of pregnancy is associated with increased activation of coagulation and a concomitant rise in fibrin(ogen) degradation products. This data shows that a combination of these tests may be capable of detecting changes in the haemostatic balance that occur before the onset of clinical signs of gynaecological problems.