Fibrinolysis in pre-eclamptic toxaemia of pregnancy

Components of the haemostatic mechanism in twin pregnancy

Components of the haemostatic mechanism were measured at intervals throughout pregnancy in 11 patients with twins and compared with a group of 21 patients with singleton pregnancies. Mean plasma fibrinogen levels were consistently (but not significantly) elevated in the mothers of twins while other parameters showed no differences.

Coagulation and the hypertensive diseases of pregnancy

The coagulation and fibrinolytic systems were investigated in a group of patients with essential hypertension during pregnancy, and the findings were compared with those of normal gravid women. Patients with essential hypertension exhibited the following significant differences: shortened partial thromboplastin times, thrombocytopenia, and decreased antithrombin III levels. Euglobulin lysis times and assays for fibrin breakdown products suggest that essential hypertension is not associated with changes in the fibrinolytic mechanism. Until more sophisticated studies can be performed on such patients, it cannot be concluded that the increased coagulability observed in pregnant patients with essential hypertension represents a state of intravascular coagulation.

Treatment of recurrent pregnancy hypertension by prophylactic anticoagulation

A patient is described who had two pregnancies complicated by severe pre-eclampsia in the second trimester which resulted in intrauterine death. During the third pregnancy anticoagulant therapy with warfarin was instituted at 14 weeks gestation and a healthy female infant was delivered at 38 weeks gestation.

Use of coagulation tests to predict the clinical progress of pre-eclampsia

The clinical manifestations of severe pre-eclampsia are normally separated from those of mild pre-eclampsia and normal pregnancy on arbitrary grounds. A clinical index, based on the increase in diastolic blood-pressure and the presence of proteinuria, was developed to reflect the spectrum of disease from mild to severe pre-eclampsia. This was related to a coagulation index based on the platelet-count, plasma-factor-VIII, and serum-fibrinolytic-degradation-products. The two indices were shown to be strongly correlated. All cases of perinatal death associated with pre-eclampsia had coagulation indices in the most severely abnormal range. These results suggest that intravascular coagulation is a highly characteristic feature of pre-eclampsia and that the coagulation index may be of value in monitoring the progress of the disease.

A serial study of coagulation factors XII, XI and X in plasma in normal pregnancy and in pregnancy complicated by pre-eclampsia

A serial study of coagulation factors XII, XI and X in plasma has been carried out on 60 primigravidae, prospectively comparing those who remained normal with those who developed pre-eclampsia. In the normal group of 48 patients, the levels of all factors rose as pregnancy advanced, a secondary increase in factors XI and X occurring in the puerperium. Cord levels of all three factors were depressed. In the pre-eclampsia group of 12 patients, factor XII was significantly higher than in the normal group throughout the study, while factors XI and X were slightly lower. Observed changes failed to support the idea of a strong primary role for the coagulation mechanism in the pathogenesis of pre-eclampsia.

Intravascular coagulation in obstetrics: Serial dilution protamine sulfate test throughout labor

Serial dilution protamine sulfate tests (SDPS) were performed in 191 women during labor. It was found that 27 per cent of women with uncomplicated pregnancies and 42 per cent with complicated pregnancies had positive SDPS tests, the highest incidence being between three and six hours of labor. These findings support the previous report of a physiologic disseminated intravascular coagulation in pregnancy but make the SDPS test of little value in obstetric cases.

Failure of heparin therapy to affect the clinical course of severe pre-eclampsia

In view of the association between pre-eclampsia and disseminated intravascular coagulation, three patients presenting with severe pre-eclampsia before the 28th week of pregnancy were treated with heparin. In all three patients, there was deterioration of hypertension and proteinuria that necessitated the withdrawal of treatment after five to six days. During treatment, serum and urinary fibrinolytic degradation products (FDPs) continued to rise or remained unaltered, plasminogen levels showed a steady fall, and the platelet count remained at a reduced level. These data suggest that heparin was an ineffective form of treatment and did not prevent the intravascular fibrin deposition associated with severe pre-eclampsia.

Blood coagulation profile in Indian patients with pre-eclampsia and eclampsia

Twelve Indian patients with pre-eclampsia, 15 with eclampsia and 15 with normal pregnancy in the third trimester were investigated. A systemic bleeding diathesis was encountered in two patients with eclampsia and in none with pre-eclampsia; two patients with pre-eclampsia, however, had excessive uterine haemorrhage. Coagulation studies showed statistically significant prolongation of thrombin time, elevation of serum fibrinogen degradation products (FDP) and hypofibrinogenaemia in patients with pre-eclampsia as well as eclampsia. In patients with eclampsia, significant thrombocytopenia also occurred. Euglobulin lysis time showed no significant change in patients with pre-eclampsia and eclampsia. There was no significant difference in the coagulation profile between patients with eclampsia and pre-eclampsia, except for more hypofibrinogenaemia in the former. The laboratory findings suggest the occurrence of intravascular coagulation in patients with pre-eclampsia and eclampsia.

Assessment of coagulation and fibrinolysis in pre-eclampsia

A method is described for distinguishing coagulation from fibrinolysis by three estimates of fibrinogen. This "fibrinogen series" together with plasma antithrombin and urinary urokinase have been compared in pregnant patients with venous thrombosis and pre-eclampsia. Evidence is presented for active coagulation during deterioration of the pre-eclampsia state and for enhanced fibrinolysis during improvement.

Coagulation and fibrinolytic systems in pre-eclampsia and eclampsia

The coagulation and fibrinolytic mechanisms were investigated in a group of patients with severe pre-eclampsia and eclampsia and the findings were compared with those of healthy women in late pregnancy. In patients with pre-eclampsia the following significant differences were found: (1) greater depression of plasma fibrinolytic activity (euglobulin lysis time) than in normal pregnancy, (2) a higher level of inhibitor to urokinaseinduced lysis, (3) increased levels of serum fibrin degradation products, and (4) reduced platelet counts.In patients with eclampsia a progressive increase of the level of serum fibrin degradation products was found over the three days following eclamptic seizures. No such increase occurred after grand mal seizures in late pregnancy. The findings in this study support the view that intravascular clotting is taking place in pre-eclampsia and that this disturbance of the balance between coagulation and fibrinolysis may be localized to certain areas of the vascular compartment, particularly the placental and renal circulations. Fibrin deposition in the maternal vessels supplying the placenta would impair the placental blood flow, which may explain the placental insufficiency which occurs in pre-eclampsia. Likewise fibrin deposition in the renal vasculature will result in glomerular damage and proteinuria. Hypertension may be related to the renal ischaemic changes or a compensatory response to the presence of fibrin deposition in the vascular compartment. This evidence of intravascular fibrin deposition raises the question of the possible therapeutic value of antithrombotic agents to inhibit the clotting process. On a theoretical basis such treatment might be expected to improve blood flow to the placenta and thereby fetal growth.

Fibrin degradation products in pre-eclamptic toxaemia and eclampsia

Serum levels of fibrinogen/fibrin degradation products, measured in African women, were significantly higher in pre-eclamptic toxaemia than in normal pregnancy, and were significantly higher with eclampsia than with toxaemia. These findings are in accord with the hypothesis that eclampsia and toxaemia are associated with disseminated intravascular coagulation, which may be responsible for certain clinical manifestations of these conditions.

Study of proteins and fibrinolysis in patients with glomerulonephritis

Plasma and urine fibrinolysis were studied in 36 patients with glomerulonephritis and proteinuria. In 40% of these plasma fibrinolytic activator activity was moderately reduced and fibrinolytic inhibitors were increased. Globulins with antiplasmin effect were raised, particularly in the earlier months. Both the serum cholesterol and the plasma fibrinogen were related to the level of serum albumin, and those patients with high fibrinogen levels were also those with poor plasma fibrinolytic activator and those showing a steady deterioration. Urinary fibrinolysis was greatly reduced in most patients and bore no relation to plasma fibrinolysis levels. Hence urokinase is not derived from circulating plasminogen activator.