Hypercoagulable states in pregnancy

Treatment of venous thromboembolism in pregnancy

Venous thromboembolism is a major preventable cause of maternal mortality in developed countries. Following objective diagnosis of deep vein thrombosis or pulmonary embolism, appropriate treatment with anticoagulation should be initiated. The therapeutic options in pregnancy are limited to the use of either unfractionated heparin or low molecular weight heparin. Oral anticoagulants, like warfarin, are relatively contraindicated for use during pregnancy for the treatment of venous thromboembolism because they freely cross the placenta and can be associated with adverse fetal effects. The appropriate length of treatment for acute venous thromboembolic disease diagnosed during pregnancy should be at least 3 months and possibly up till 6 weeks after delivery.

Diagnosis of deep vein thrombosis and pulmonary embolism in pregnancy

Venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality. Because unrecognized and untreated pulmonary embolism (PE) can result in maternal mortality, physician vigilance for this disease should remain high. The diagnosis of both PE and deep vein thrombosis (DVT) in the pregnant patient, as in the nonpregnant patient, requires the use of accurate objective imaging. However, unlike the nonpregnant population, there is a paucity of trials evaluating the safety and accuracy of objective testing for PE or DVT diagnosis in pregnant patients--likely because of concerns surrounding the use of ionizing radiation associated with diagnostic tests during pregnancy. Regardless of extrapolating results from studies in the nonpregnant population, the use of compression leg ultrasound and ventilation-perfusion (VQ) scanning during pregnancy is central to the diagnosis of DVT and PE, respectively. Data on the utility of structured clinical models or D-dimer testing for the diagnosis of DVT or PE during pregnancy is currently unavailable. Future research is urgently needed to validate the use of current approaches and perhaps define safer and more accurate strategies to reduce maternal morbidity from this disease.

Pathological state of the coagulatory and fibrinolytic system in preeclampsia and the possibility of its treatment with AT III concentrate

Forty patients with preeclampsia were collected, and 27 of these cases were treated with AT III concentrate (1,000-2,000 units/day) for 7 days. According to an evaluation of objective clinical efficacy by the degree of improvement of GI scores in patients with preeclampsia, the number of effective cases was significantly greater among the treated groups than among the untreated groups (p less than 0.05). The rate of efficacy of the treated groups was 40%, compared with 0% in the untreated groups. In severe preeclampsia, a decrease in AT III activity was noted in 56.7%, a decrease in platelet count in 62.1%, and an increase in plasma FDP in 46.2%. A significant correlation was found between the GI score and the AT III activity. The anticoagulation therapy using AT III may normalize the chronic coagulation accelerated state in preeclampsia, and a good influence on the fetus may be expected.

Glycosaminoglycan patterns in diabetic and toxemic term placentas

Crude glycosaminoglycans were prepared from acetone powder of diabetic, toxemic, and normal term placentas. Glycosaminoglycan composition was determined by electrophoresis and densitometric scanning with and without treatment with testicular hyaluronidase and chondroitinase ABC. The identity of individual glycosaminoglycans was confirmed by the nature of their hexosamine. Glycosaminoglycan content was found to be significantly increased in diabetic placentas and increased to a lesser degree in the toxemic placentas. The amount of hyaluronic acid was elevated in both abnormal tissues, and heparan sulfate was slightly higher in diabetes, while unchanged in toxemia. Dermatan sulfate was markedly reduced in the abnormal placentas while chondroitin 4/6 sulfate was unaltered. An attempt was made to correlate the histopathologic changes reported to occur in these conditions with the alterations in the glycosaminoglycans patterns of placentas.

The hypercoagulability states

Although interest in coagulation has usually centered about the various hemorraghic disorders, it is hyperactivity of the hemostatic system with its thrombotic complications which has a far greater clinical impact. The hypercoagulability states are a vague group of disorders not well defined by the laboratory. They fall into two distinct groups: (1) conditions promoting venous thrombosis by activating the coagulation mechanism and (2) conditions promoting arterial thrombosis by platelet plug formation. Dealing with both of these groups separately the various disorders associated with a hypercoagulable state are discussed as well as their pathophysiologic basis; Special emphasis is placed on the laboratory evaluation of these disorders.

Fetal death: coagulation defects and management. Report of 20 cases with study of the half-life of [125I]fibrinogen

This report concerns 20 patients with intrauterine fetal death. Blood samples for coagulation studies were obtained before, during and after delivery. No clinical defibrination or bleeding was noted. Coagulation defects were observed as follows: 2 biological defibrinations: The first case was a pregnancy of 32 wk with retention for more than 12 wk; hypofibrinogenemia was noted in all 6 samples, between 180 and 280 mg/100 ml. The second was a pregnancy of 32 wk with retention for more than 8 wk; fibrinogenemia was between 170 mg/100 ml and 140 mg/100 ml. 2 intravascular coagulations with normal fibrinogenemia, increase of fibrin degradation products and positive ethanol tests. 3 cases with slight coagulation defects that were difficult to explain. The coagulation defects appeared to be transient, and sometimes resolved themselves spontaneously. Induction of labour was made in 19 cases; quinine sulfate, used in 17 cases, was remarkably successful (1 intolerance, 1 failure). Study of the half-life of [125I]fibrinogen was made in 18 of the 20 cases. On average, it was reduced by half in comparison with the half-life of healthy men. The decrease was noted even in cases of fetal deaths without the coagulation defects detected by classical tests. The half-life of [125I]fibrinogen in 6 pregnant women before therapeutic abortion was also studied. The decrease of half-life was noted. Changes of metabolism of fibrinogen during pregnancy are discussed.

Reversal of hypercoagulable state by bilateral nephrectomy

The hypercoagulable state associated with select cases of glomerulonephritis is difficult to diagnose by standard laboratory techniques but is clinically manifested by recurrent shunt and fistula thrombosis which may be refractory to anticoagulant therapy. Bilateral nephrectomy reversed this hypercoagulable state. After renal allograft, however, the patient experienced hyperacute rejection, and transplant nephrectomy was required to cure the recurrent hypercoagulable state. The mechanism of this previously unreported phenomenon and its implications with regard to renal transplantation are discussed.

Treatment of pre-eclampsia and eclampsia as a hypoperfusion syndrome

A therapeutical program in pre-eclampsia and eclampsia is presented. The results in 10 patients suggest that the same basic program as is used in the hypoperfusion syndrome can be used in pre-eclampsia and eclampsia: Chlorpromazin to combat vasoconstriction and dilate the vascular bed. Plasma expanders, plasma, albumin and glucose with electrolytes to fill up the dilated vascular bed and restore the tissue perfusion. Buffers to combat acidosis, oxygen to combat hypoxemia, hypertonic Mannitol to mobilize edema. Furosemide to force diuresis.

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.