American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy

Abstract

Background: Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality. Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE. Methods: ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations. Results: The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis. Conclusions: There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.

Use of a personalized iterative score to evaluate risk of venous thromboembolism during pregnancy and puerperium

“…Fourth, the present findings indicated an appreciable increase in treatment duration after implementation of the VTE risk score. Anticoagulants were previously prescribed during pregnancy and for 6 weeks during puerperium for scores higher than 3 . Use of the VTE risk score from the start of pregnancy might explain the prolonged duration of anticoagulation with no information about treatment compliance in the present study.…”

“…The current iterative assessment seemed necessary to enable appropriate prophylaxis of a complex and multifactorial disease, with multiple but conflicting published guidelines . Use of the VTE risk score markedly reduced the likelihood of undertreatment or overtreatment during pregnancy and puerperium.…”

“…The originality of the current VTE risk score lay in its iterative design and the inclusion of VTE risk factors not used in other models, especially for puerperium. The current score could evolve as knowledge of VTE risk factors increases.…”

“…Several scores are available to assess VTE risk during pregnancy . The score devised by Dargaud et al .…”

Thrombosis and hemostasis health in pregnancy: Registries from the International Society on Thrombosis and Haemostasis

“…Further, there were few cases of pregnancy‐related massive PE treated with ECMO and with percutaneous thrombectomy. Given this lack of strong evidence, current guidelines consider pregnancy as a relative contraindication to the use of thrombolytics but advise to administer thrombolytic therapy for life‐threatening pregnancy‐related PE …”