Guideline sources The following summarized guidelines for the evaluation and management of venous thromboembolism in pregnancy (VTE in pregnancy) are prepared by our editorial team based on guidelines from the American Society of Hematology (ASH 2018). 1 Guidelines 1. Diagnostic investigations Evaluation for deep vein thrombosis: consider additional investigations (including serial compression ultrasound or MRV) after an initial negative ultrasound with for pregnant women with suspected deep vein thrombosis. C Evaluation for pulmonary embolism: consider ventilation-perfusion lung scanning rather than CT pulmonary angiogram as a first-line diagnostic imaging modality for pregnant women with suspected PE. C 2. Medical management General principles: initiate antithrombotic therapy in pregnant women with acute VTE. A Setting of care: consider initial outpatient therapy over hospital admission for pregnant women with low-risk acute VTE. C https://web.pathway.md/diseases/recWDbnj0jDfcfaqG 1/4 6/29/23, 3:25 AM Venous thromboembolism in pregnancy Pathway Choice of anticoagulant therapy: administer LMWH rather than UFH for pregnant women with acute VTE. B Show 2 more Thrombolytic therapy: consider administering systemic thrombolytic therapy in addition to anticoagulant therapy for pregnant women with acute PE and life-threatening hemodynamic instability. C Timing of delivery: consider scheduled delivery with prior discontinuation of anticoagulant therapy for pregnant women receiving therapeutic LMWH for VTE. C 3. Therapeutic procedures Catheter-directed thrombolysis: consider avoiding catheter-directed thrombolysis therapy in pregnant women with acute lower-extremity deep vein thrombosis. D 4. Specific circumstances Patients undergoing assisted reproduction: Consider avoiding prophylactic antithrombotic therapy to prevent VTE in unselected women undergoing assisted reproductive therapy. D Consider prophylactic antithrombotic therapy to prevent VTE in women undergoing assisted reproductive therapy, who develop severe ovarian hyperstimulation syndrome. C Patients with superficial venous thrombosis: consider administering LMWH for pregnant women with proven acute superficial vein thrombosis. C Patients who are breastfeeding: use UFH, LMWH, warfarin, acenocoumarol, fondaparinux, or danaparoid in women who are breastfeeding and have an indication for anticoagulation. B 5. Preventative measures Antepartum prophylaxis (primary prevention): consider administering primary prophylaxis for VTE during the antepartum period in women with antithrombin deficiency who have a family history of VTE, and in women who are homozygous for the FVL mutation or who have combined thrombophilias. C Show 2 more Antepartum prophylaxis (secondary prevention): Administer secondary prophylaxis for VTE in women not already receiving long-term anticoagulant therapy who have a history of unprovoked VTE, or one that was associated with a hormonal risk factor. B Consider avoiding secondary prophylaxis for VTE in women not already receiving long-term anticoagulant therapy who have a history of prior VTE associated with a nonhormonal temporary provoking risk factor and no other risk factors. D Postpartum prophylaxis (primary prevention): administer primary prophylaxis for VTE during the postpartum period in women with a family history of VTE who have antithrombin https://web.pathway.md/diseases/recWDbnj0jDfcfaqG 2/4 6/29/23, 3:25 AM Venous thromboembolism in pregnancy Pathway deficiency. B Show 4 more Postpartum prophylaxis (secondary prevention): administer secondary prophylaxis for VTE during the postpartum period in women not already receiving long-term anticoagulant therapy who have a history of VTE. B Dosing of prophylactic LMWH: Consider avoiding intermediate LMWH dosing regimens (as opposed to standard dosing regimens) in women requiring VTE prophylaxis during the antepartum period. D Consider either standard or intermediate LMWH dosing regimens in women requiring VTE prophylaxis during the postpartum period. C Clinical findings Symptoms Past medical history Calf or thigh pain Diabetes mellitus Chest pain IBD Cough Obesity Coughing up blood VTE Leg pain Family history Leg swelling VTE Past obstetric history Vital signs Preeclampsia Strict bed rest during pregnancy Tachycardia Social history Current cigarette smoking Vascular exam Calf or thigh swelling References 1. Bates SM, Rajasekhar A, Middeldorp S et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy. Blood Adv. 2018 Nov 27;2 22 3317 3359. Open 2. Regitz-Zagrosek V, Roos-Hesselink JW, Bauersachs J et al. 2018 ESC Guidelines for the management of cardiovascular diseases during pregnancy. Eur Heart J. 2018 Sep 7;39 34 3165 3241. Open 3. Saskia Middeldorp, Robby Nieuwlaat, Lisa Baumann Kreuziger et al. American Society of Hematology 2023 Guidelines for Management of Venous Thromboembolism: Thrombophilia Testing. Blood Adv. 2023 May 17;bloodadvances.2023010177. Open https://web.pathway.md/diseases/recWDbnj0jDfcfaqG 3/4 6/29/23, 3:25 AM Venous thromboembolism in pregnancy Pathway 4. Kearon C, Akl EA, Ornelas J et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report. Chest. 2016 Feb;149 2 315 352. Open 5. Shannon M Bates, Ian A Greer, Saskia Middeldorp et al. VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012 Feb;141 2 Suppl):e691S- e736S. Open 6. Royal College of Gynaecologists and Obstetricians. Reducing the Risk of Venous Thromboembolism during Pregnancy and the Puerperium: Green-top Guideline No. 37a. RCOG. 2015 Apr. Open 7. Royal College of Gynaecologists and Obstetricians. Thromboembolic Disease in Pregnancy and the Puerperium: Acute Management: Green-top Guideline No. 37b. RCOG. 2015 Apr. Open https://web.pathway.md/diseases/recWDbnj0jDfcfaqG 4/4