Venous Thromboembolism In Pregnancy Research Articles

Low molecular weight heparin for the treatment of venous thromboembolism in pregnancy: a case series

Objectives To assess the use of low molecular weight heparin for the treatment of venous thromboembolism in pregnancy. Design A prospective observational study. Setting The maternity units in two university teaching hospitals and one district general teaching hospital. Population Thirty-six consecutive women presenting with objectively diagnosed venous thromboembolism during pregnancy and the immediate puerperium. Methods Treatment with the low molecular weight heparin enoxaparin, approximately 1 mg/kg sc, twice daily, based on early pregnancy weight. Main outcome measures Peak anti-Xa activity (three hours post-injection), alterations in treatment, side effects and the use of regional anaesthesia. Results In 33 women, the initial dose of enoxaparin provided satisfactory peak anti-Xa activity (median 0.8 u/mL, range 0.44–1.0 u/mL) and was continued. Three women required dose reduction since peak anti-Xa activities were above the therapeutic range (1.2, 1.2 and 1.1 u/mL). No woman developed thrombocytopaenia, haemorrhagic complication or further thromboembolic episode. Two women developed allergic skin reactions on enoxaparin and were changed to tinzaparin. Fifteen women had regional anaesthesia for delivery, with a reduced dose of enoxaparin (40 mg once daily), all without complication. Conclusions Enoxaparin is a safe and effective treatment for venous thromboembolism during pregnancy and confers a major advantage over unfractionated heparin through its simplified regimen of administration.

Use of Low Molecular Weight Heparin in Acute Venous Thromboembolic Events in Pregnancy

Objective: To compare the maternal and neonatal outcomes arising from the use of low molecular weight heparin (LMWH) or unfractioned heparin (UFH) in the treatment of acute venous thromboembolism (VTE) in pregnancy.Study Design: A retrospective review of the charts of all women treated for acute VTE in pregnancy at the Ottawa Hospital from January 1990 to December 1999.Results: Twenty-three cases were identified, of which 11 were treated with LMWH and 12 with UFH. Maternal and fetal outcomes were similar between the two groups. Hospital length of stay was shorter in the LMWH group. There was no difference in delivery management between the two groups. There was minor bleeding in 2 women in the UFH group and none in the LMWH group. There was one recurrent VTE during treatment in each of the groups.Conclusion: There is no difference in complication rate between LMWH and UFH in the treatment of acute VTE in pregnancy.

Cumulative incidence of venous thromboembolism during pregnancy and puerperium: a hospital-based study.

Pregnancy is associated with an increased risk of venous thromboembolism. The rate of occurrence of this complication has not been reported from this area previously. The aim of this study was to establish the incidence of venous thromboembolism in pregnancy and puerperium by using objective diagnostic methods. From January 1986 to December 1998, 39,757 deliveries were registered at King Fahad Hospital, Al Baha, and 59 of these were referred to hematology services with a clinical suspicion of venous thromboembolism. The majority (86%) of these underwent objective diagnostic methods such as ascending venogram (AV) and color Doppler imaging (CDI) of the venous system for the diagnosis of deep venous thrombosis (DVT). Pulmonary scintigraphy was performed when available and echocardiography was included towards the end of the study. Fifty-nine patients with suspicion of pregnancy-associated venous thromboembolism (PAVTE) were studied. The diagnosis was confirmed in 50 patients, who received anticoagulation therapy. DVT was diagnosed in 35 (70%) cases and pulmonary embolism in 27 (54%) cases. The cumulative incidence of PAVTE was 1.25 cases per 1,000 deliveries (95% confidence interval = 0.89-1.16). One patient died during the study period (0.025 case per 1,000 deliveries). There was a predominance of venous thromboembolism during the postpartum period (66%), and DVT occurred more frequently in the left leg (77%). The risk of pregnancy-associated venous thromboembolism is low and a resulting death rare. Proximal or whole-limb DVT occurs more frequently and there is a predilection for the left leg. The majority of events occur in the postpartum period. A hypercoagulable state probably exists and needs further evaluation.

PRL as a Novel Potent Cofactor for Platelet Aggregation

Pregnancy (including puerperium) is a period of hypercoagulability and seems to be an independent major risk factor for venous thromboembolism (VTE). However, the basis of the increased risk of VTE in pregnancy and around delivery is unknown. We hypothesized that changes in PRL, which is a prominently increased hormone during pregnancy and lactation, might be involved in the activation of platelets. To investigate platelet functional abnormalities in pregnancy, we assessed the ADP-stimulated and nonstimulated P-selectin expression of platelets in 42 consecutive pregnant women, 22 normo- and hyperprolactinemic patients with pituitary tumors, and controls. In addition, the aggregation of platelets by human PRL in vitro was studied. We found a significant correlation between PRL values and ADP stimulation of platelets in pregnant women (r = 0.56; P < 0.0001) and patients with pituitary tumors (r = 0.57; P = 0.006). Hyperprolactinemic pregnant women or hyperprolactinemic patients with pituitary tumors revealed significantly higher ADP stimulation of platelets (P < 0.0001) than healthy controls or normoprolactinemic patients with pituitary tumors. These results were reconciled by increased in vitro stimulation and aggregation of platelets using human PRL. Our novel findings demonstrate that hyperprolactinemia causes increased platelet aggregation via ADP stimulation both in vitro and in vivo. Moreover, our data indicate that PRL may be a physiological cofactor of the delicate coagulation balance during pregnancy and puerperium that might explain the increased risk of VTE in pregnant women around delivery. Further studies of the interaction between PRL and platelets will clarify the clinical relevance of hyperprolactinemia as a potential risk factor for VTE.

The acute management of venous thromboembolism in pregnancy

Pulmonary thromboembolism is the leading cause of maternal death in the UK. Optimal management of deep venous thrombosis and pulmonary thromboembolism requires an appreciation of risk factors, particularly thrombophilia, and signs or symptoms suggestive of venous thromboembolism, along with objective diagnosis and treatment with anticoagulants. Low molecular weight heparins are now replacing unfractionated heparin for the treatment of deep venous thrombosis and pulmonary thromboembolism in pregnancy because of the lower risk of side effects, ease of administration and reduced need for monitoring.

PRL as a novel potent cofactor for platelet aggregation.

Pregnancy (including puerperium) is a period of hypercoagulability and seems to be an independent major risk factor for venous thromboembolism (VTE). However, the basis of the increased risk of VTE in pregnancy and around delivery is unknown. We hypothesized that changes in PRL, which is a prominently increased hormone during pregnancy and lactation, might be involved in the activation of platelets. To investigate platelet functional abnormalities in pregnancy, we assessed the ADP-stimulated and nonstimulated P-selectin expression of platelets in 42 consecutive pregnant women, 22 normo- and hyperprolactinemic patients with pituitary tumors, and controls. In addition, the aggregation of platelets by human PRL in vitro was studied. We found a significant correlation between PRL values and ADP stimulation of platelets in pregnant women (r = 0.56; P < 0.0001) and patients with pituitary tumors (r = 0.57; P = 0.006). Hyperprolactinemic pregnant women or hyperprolactinemic patients with pituitary tumors revealed significantly higher ADP stimulation of platelets (P < 0.0001) than healthy controls or normoprolactinemic patients with pituitary tumors. These results were reconciled by increased in vitro stimulation and aggregation of platelets using human PRL. Our novel findings demonstrate that hyperprolactinemia causes increased platelet aggregation via ADP stimulation both in vitro and in vivo. Moreover, our data indicate that PRL may be a physiological cofactor of the delicate coagulation balance during pregnancy and puerperium that might explain the increased risk of VTE in pregnant women around delivery. Further studies of the interaction between PRL and platelets will clarify the clinical relevance of hyperprolactinemia as a potential risk factor for VTE.

A family history can display a synergistic effect of atherogenic and prothrombotic risk in pregnancy

A family history can display a synergistic effect of atherogenic and prothrombotic risk in pregnancy

Management of venous thromboembolism in pregnancy

Pulmonary thromboembolism (PTE) is the major cause of maternal death in the UK, with recent trends showing an increase in the numbers of deaths. Underlying PTE is the problem of deep venous thrombosis (DVT). An appreciation of risk factors, particularly, thrombophilia, and signs or symptoms suggestive of thromboembolism, coupled with objective diagnosis and treatment should reduce mortality and morbidity. There are particular considerations with regard to the management of thrombosis in pregnancy, especially the use of anticoagulants. Low-molecular-weight heparins are now replacing unfractionated heparin for the treatment of DVT and PTE in pregnancy.

Use of enoxaparin in a pregnant woman with a mechanical heart valve prosthesis

To assess the safety and efficacy of low-molecular-weight heparins (LMWHs) for thromboprophylaxis and treatment of venous thromboembolism (VTE) in pregnancy, a systematic review of studies to the end of 2003 was undertaken. Data on VTE recurrence and side effects were extracted and cumulative incidences of VTE and adverse effects calculated. Of 81 reports identified, 64 reporting 2777 pregnancies were included. In 15 studies (174 patients) the indication for LMWH was treatment of acute VTE, and in 61 studies (2603 pregnancies) it was thromboprophylaxis or adverse pregnancy outcome. There were no maternal deaths. VTE and arterial thrombosis (associated with anti-phospholipid syndrome) were reported in 0.86% (95% confidence interval [CI], 0.55%-1.28%) and 0.50% (95% CI, 0.28%-0.84%) of pregnancies, respectively. Significant bleeding, generally associated with primary obstetric causes, occurred in 1.98% (95% CI, 1.50%-2.57%), allergic skin reactions in 1.80% (95% CI, 1.34%-2.37%), heparin-induced thrombocytopenia in 0%, thrombocytopenia (unrelated to LMWH) in 0.11% (95% CI, 0.02%-0.32%), and osteoporotic fracture in 0.04% (95% CI, < 0.01%-0.20%) of pregnancies. Overall, live births were reported in 94.7% of pregnancies, including 85.4% in those receiving LMWH for recurrent pregnancy loss. LMWH is both safe and effective to prevent or treat VTE in pregnancy.

Recurrent Venous Thromboembolism in Pregnancy: Is There a Need for Thromboprophylaxis?

Synopsis: The risk of recurrent antepartum venous thromboembolism in women with a history of venous thromboembolism is low and therefore routine antepartum prophylaxis with heparin is not warranted. Source: Edwards P et al. Safety of withholding heparin in pregnant women with a history of venous thromboembolism. N Engl J Med. 2000;343:1439–1444.

Venous Thromboembolism in Pregnancy

The risk of venous thromboembolism (VTE) is increased in pregnancy and puerperium. Thrombophilia has been identified in pregnancy-related VTE. Venous ultrasound and ventilation-perfusion lung scanning are the initial tests; pulmonary angiography should be performed if necessary for the definitive diagnosis. Anticoagulation is achieved with heparin antepartum and warfarin postpartum. Low molecular weight heparin has been effective and safe in pregnancy. Thrombolytic therapy has been administered to pregnant patients.

Venous thromboembolism in pregnancy and the puerperium: incidence and additional risk factors from a London perinatal database

Objective To determine the incidence of venous thromboembolism in pregnancy and the puerperium and to identify risk factors for pregnancy-related venous thromboembolism. Design Cohort study and case–control study. Setting London, UK. Population 395,335 women with live births or pregnancies of 24 or more weeks of gestation between 1988 and 1997. Methods Data extraction from the St Mary's Maternity Information System database. Random sample of 5% for case–control study. Main outcome measures Incidence of venous thromboembolism; odds ratios for variables associated with venous thromboembolism. Results The incidence of venous thromboembolism was 85/100,000 maternities. There were approximately twice as many postpartum as antepartum events. Blood group A, multiple pregnancy, caesarean section, cardiac disease, delivery at gestational age of <36 weeks, a body mass index of ≥25, or more and maternal age of 35 or over were all found to increase incidence of venous thromboembolism. Conclusions Although venous thromboembolism is the leading cause of maternal deaths in the UK, it is still a rare event. Most of these events are deep vein thromboses occurring in the postpartum period. Antenatally multiple birth is an important risk factor. Postnatally women who have had a caesarean section, premature delivery or history of cardiac disease should be assessed carefully for venous thromboembolism.

Venous thromboembolism in pregnancy and the puerperium: incidence and additional risk factors from a London perinatal database.

To determine the incidence of venous thromboembolism in pregnancy and the puerperium and to identify risk factors for pregnancy-related venous thromboembolism. Cohort study and case-control study. London, UK. 395,335 women with live births or pregnancies of 24 or more weeks of gestation between 1988 and 1997. Data extraction from the St Mary's Maternity Information System database. Random sample of 5% for case-control study. Incidence of venous thromboembolism; odds ratios for variables associated with venous thromboembolism. The incidence of venous thromboembolism was 85/100,000 maternities. There were approximately twice as many postpartum as antepartum events. Blood group A, multiple pregnancy, caesarean section, cardiac disease, delivery at gestational age of < 36 weeks, a body mass index of > or = 25, or more and maternal age of 35 or over were all found to increase incidence of venous thromboembolism. Although venous thromboembolism is the leading cause of maternal deaths in the UK, it is still a rare event. Most of these events are deep vein thromboses occurring in the postpartum period. Antenatally multiple birth is an important risk factor. Postnatally women who have had a caesarean section, premature delivery or history of cardiac disease should be assessed carefully for venous thromboembolism.

Venous Thromboembolism in Pregnancy

The risk of venous thromboembolism (VTE) is increased in pregnancy and puerperium. Thrombophilia has been identified in pregnancy-related VTE. Venous ultrasound and ventilation-perfusion lung scanning are the initial tests; pulmonary angiography should be performed if necessary for the definitive diagnosis. Anticoagulation is achieved with heparin antepartum and warfarin postpartum. Low molecular weight heparin has been effective and safe in pregnancy. Thrombolytic therapy has been administered to pregnant patients.

Thromboembolism during pregnancy

PREVIEWVenous thromboembolism in pregnancy presents a considerable diagnostic and therapeutic challenge for primary care physicians. Not only do the physiologic and anatomic changes of pregnancy complicate interpretation of diagnostic tests, but radiologic studies and anticoagulant therapy pose health risks. This article highlights risk factors associated with venous thromboembolism in pregnancy, difficulties in diagnosis, and risks and benefits of anticoagulant therapy.

Anesthetic Management of the Parturient with Protein S Deficiency and Ischemic Heart Disease

Anesthetic Management of the Parturient with Protein S Deficiency and Ischemic Heart Disease

Risk factors for venous thromboembolism in pregnancy.

Venous thromboembolism remains the leading cause of maternal mortality in the United Kingdom. In this review we highlight studies that have documented the incidence of objectively confirmed venous thromboembolism in pregnancy, consider the effect of pregnancy on the coagulation and fibrinolytic systems, and examine in detail current knowledge of the risk factors for the development of this condition.

Low-molecular-weight heparin for immediate management of thromboembolic disease in pregnancy

women had epidural anaesthesia without complication. The fourth woman stayed in hospital and was delivered under spinal anaesthetic by caesarean section for placenta praevia. Intrapartum blood loss for each woman was within normal limits. Median peak (3 h) anti-Xa activity in the four women was 0·67 U/mL (range 0·46–1·00 on 18 observations). In one woman (weight 58 kg), a 24 h anti-Xa activity profile showed that a measurable protective anticoagulant effect (activity >0·2 U/mL) was maintained between drug administration (figure). Furthermore, in each woman, there was no cumulative anticoagulant effect. One woman, treated for 8 weeks, had monthly peak concentrations of anti-Xa of 1·00 U/mL, 1·00 U/mL, and 0·89 U/mL. The activated partial thromboplastin time for each woman remained within normal during enoxaparin treatment and no woman developed thrombocytopenia. Subcutaneous LMWH seems to have advantages over unfractionated heparin for venous thromboembolism in pregnancy. The simplified therapeutic regimen for LMWH enables patients to be treated as outpatients. LMWHs have a higher anti-factor Xa activity/anti-factor IIa activity ratio than unfractionated heparin and a more predictable dose response. LMWH may be a safe and effective treatment for venous thromboembolism in pregnancy with easy administration. Assessment of anti-Xa during treatment should, however, be carried out until greater experience is obtained.

Venous Thromboembolism in Pregnancy

Venous thromboembolism (VTE) is the leading nonobstetric cause of maternal morbidity and mortality. The risk for deep venous thrombosis (DVT) commences in the first trimester with a striking proclivity for the left lower extremity. Pulmonary embolism (PE) is more frequent in the postpartum period. Activated protein-C resistance increases the risk of VTE 30- to 50-fold in heterozygotes and several hundred-fold in homozygotes. Other inherited and acquired factors also increase the risk.

Thromboembolism in obstetrics

This review covers the epidemiology, diagnosis, treatment and prophylaxis of venous thromboembolism in pregnancy. Arterial thromboembolism particularly in relation to heart disease, although much more uncommon is also considered.