A descriptive evaluation of unfractionated heparin use during pregnancy

Pulmonary Embolism in Pregnancy

Even though venous thromboembolism is a leading cause of maternal mortality in high-income countries, there are limited high-quality data to assist clinicians with the management of pulmonary embolism in this patient population. Diagnosis, prevention, and treatment of pregnancy-associated pulmonary embolism are complicated by the need to consider fetal, as well as maternal, well-being. Recent studies suggest that clinical prediction rules and D-dimer testing can reduce the need for diagnostic imaging in a subset of patients. Low-molecular-weight heparin is the preferred anticoagulant for both prophylaxis and treatment in this setting. Direct oral anticoagulants are contraindicated during pregnancy and in breastfeeding women. Thrombolysis or embolectomy should be considered for pregnant women with pulmonary embolism complicated by hemodynamic instability. Treatment of pregnancy-associated pulmonary embolism should be continued for at least 3 months, including 6 weeks postpartum. Management of anticoagulants at the time of delivery should involve a multidisciplinary individualized approach that uses shared decision making to take patient and caregiver values and preferences into account.

Venous Thromboembolism Risk and Adequacy of Prophylaxis in High Risk Pregnancy in the Arabian Gulf

Objectives: To estimate the prevalence of venous thromboembolism (VTE) risk factors in pregnancy and the proportion of pregnancies at risk of VTE that received the recommended prophylaxis according to the American College of Chest Physicians (ACCP) 2012 published guidelines in antenatal clinics in the Arabian Gulf.

Methods: The evaluation of venous thromboembolism (EVE)-Risk project was a non-interventional, cross-sectional, multi-centre, multi-national study of all eligible pregnant women (≥17 years) screened during antenatal clinics from 7 centres in the Arabian Gulf countries (United Arab Emirates, Kuwait, Bahrain, Qatar and Oman). Pregnant women were recruited during a 3-month period between September and December 2012.

Results: Of 4,131 screened pregnant women, 32% (n=1,337) had ≥1 risk factors for VTE. Common VTE risk factors included obesity (76%), multiparity (33%), recurrent miscarriages (9.1%), varicose veins (6.9%), thrombophilia (2.6%), immobilization (2.0%), sickle cell disease (2.8%) and previous VTE (1.6%). Only 8.3% (n=111) of the high risk patients were on the recommended VTE prophylaxis. Enoxaparin was used in 80% (n=89) of the cases followed by tinzaparin (4%; n=4). Antiplatelet agents were prescribed in 11% (n=149) of pregnant women. Of those on anticoagulants (n=111), 59% (n=66) were also co-prescribed antiplatelet agents. Side effects (mainly local bruising at the injection site) were reported in 12% (n=13) of the cases.

Conclusion: A large proportion of pregnant women in the Arabian Gulf countries have ≥1 VTE risk factor with even a smaller fraction on prophylaxis. VTE risk assessment must be adopted to identify those at risk who would need VTE prophylaxis.

Guidance for the practical management of warfarin therapy in the treatment of venous thromboembolism

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. The treatment of VTE is undergoing tremendous changes with the introduction of the new direct oral anticoagulants and clinicians need to understand new treatment paradigms. This article, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. Well-managed warfarin therapy remains an important anticoagulant option and it is hoped that anticoagulation providers will find the guidance contained in this article increases their ability to achieve optimal outcomes for their patients with VTE Pivotal practical questions pertaining to this topic were developed by consensus of the authors and were derived from evidence-based consensus statements whenever possible. The medical literature was reviewed and summarized using guidance statements that reflect the consensus opinion(s) of all authors and the endorsement of the Anticoagulation Forum’s Board of Directors. In an effort to provide practical and implementable information about VTE and its treatment, guidance statements pertaining to choosing good candidates for warfarin therapy, warfarin initiation, optimizing warfarin control, invasive procedure management, excessive anticoagulation, subtherapeutic anticoagulation, drug interactions, switching between anticoagulants, and care transitions are provided.

Reducing the risk of venous thromboembolism in pregnancy--The safe motherhood initiative thromboembolism bundle

Maternal mortality from venous thromboembolism (VTE) remains a significant cause of direct maternal death, and one that is largely preventable. The incidence of VTE in pregnancy and the postnatal period is, however, rising in the United States, likely reflecting increasing obesity and operative delivery rates. There is a clear need to establish and implement risk assessment tools and thromboprophylaxis guidelines in an effort to curb these rising rates and reverse this current trend. In this article, Friedman and D'Alton introduce a thromboembolism bundle of recommendations from the Safe Motherhood Initiative, which aim to do just that. In this article, we review the recommendations made, and compare to established guidelines, such as those from the Royal College of Obstetricians and Gynaecologists, which have successfully reduced maternal mortality from VTE following publication.

Guidance for the treatment and prevention of obstetric-associated venous thromboembolism

Venous thromboembolism (VTE), which may manifest as pulmonary embolism (PE) or deep vein thrombosis (DVT), is a serious and potentially fatal condition. Treatment and prevention of obstetric-related VTE is complicated by the need to consider fetal, as well as maternal, wellbeing when making management decisions. Although absolute VTE rates in this population are low, obstetric-associated VTE is an important cause of maternal morbidity and mortality. This manuscript, initiated by the Anticoagulation Forum, provides practical clinical guidance on the prevention and treatment of obstetric-associated VTE based on existing guidelines and consensus expert opinion based on available literature where guidelines are lacking.

Preventing thrombophilia-related complications of pregnancy: an update

Approximately half of all pregnancy-related venous thromboembolic events are associated with thrombophilia. Although the most compelling data for a link between thrombophilia and other adverse pregnancy outcomes derive from women with antiphospholipid antibodies, some studies also suggest an association between these pregnancy complications and hereditary thrombophilias. Management of thrombophilia often involves anticoagulant therapy; however, use of these agents during pregnancy is challenging. There is a paucity of high-quality studies and consequently, recommendations are based largely on extrapolation from data in nonpregnant women, in addition to observational studies and a few small randomized studies. This article will review the impact of the thrombophilias on pregnancy and its outcome, evidence for therapies aimed at the prevention of thrombophilia-related pregnancy complications, and the most recent recommendations contained in the 9th Edition of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

Anticoagulant therapy for venous thromboembolism during pregnancy: a systematic review and a meta-analysis of the literature

Venous thromboembolism (VTE) is one of the most relevant causes of maternal death in industrialized countries. Low molecular weight heparin (LMWH), continued throughout the entire pregnancy and puerperium, is currently the preferred treatment for patients with acute VTE occurring during pregnancy. However, information on the efficacy and safety of anticoagulant drugs in this setting is extremely limited. We carried out a systematic review and a meta-analysis of the literature to provide an estimate of the risk of bleeding complications and VTE recurrence in patients with acute VTE during pregnancy treated with antithrombotic therapy. The weight mean incidence (WMI) of bleeding and thromboembolic events and the corresponding 95% confidence interval (CI) were calculated. Eighteen studies, giving a total of 981 pregnant patients with acute VTE, were included. LMWH was prescribed to 822 patients; the remainder were treated with unfractionated heparin. Anticoagulant therapy was associated with WMIs of major bleeding of 1.41% (95% CI 0.60-2.41%; I) antenatally and 1.90% (95% CI 0.80-3.60%) during the first 24 h after delivery. The estimated WMI of recurrent VTE during pregnancy was 1.97% (95% CI 0.88-3.49%; I(2) 39.5%). Anticoagulant therapy appears to be safe and effective for the treatment of pregnancy-related VTE, but the optimal dosing regimens remain uncertain.

Pregnancy-associated venous thromboembolism: prevention and treatment

Pregnancy is associated with an increased risk of venous thromboembolism (VTE) and this condition remains an important cause of maternal morbidity and mortality. The use of anticoagulant therapy for treatment and prophylaxis of VTE during pregnancy is challenging because of the potential for fetal, as well as maternal, complications. Although evidence-based recommendations for the use of anticoagulants have been published, given the paucity of available data, guidelines are based largely upon observational studies and from data in nonpregnant patients. This article reviews the available literature and provides guidance for the management and prevention of VTE during pregnancy.

VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.

METHODS

The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).

CONCLUSIONS

Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.