Women are at increased risk for VTE during
pregnancy and the postpartum period. Awareness of risk factors and the signs and symptoms of
VTE is paramount. Prompt diagnosis and treatment is mandatory to decrease complications of
VTE. LMWH is the mainstay treatment of VTE in
pregnancy, as it does not cross the placenta. Both
LMWH and warfarin are safe during lactation.
Close communication among the patient, obstetrician, hematologist, anesthesiologist, and neonatolo-gist is crucial to optimize the care of these patients.
1. Knight M, Nour M, Tuffnell D, et al, eds. on behalf of MBRRACE-UK. Saving
lives, improving mothers’ care—surveillance of maternal deaths in the UK
2012-14 and lessons learned to inform maternity care from the UK and Ireland
confidential enquiries into maternal deaths and morbidity 2009-14. Oxford:
National Perinatal Epidemiology Unit, University of Oxford; 2016: 69–75.
2. Berg CJ, Callaghan WM, Syverson C, Henderson Z. Pregnancy-related mortality in the United States, 1998 to 2005. Obstet Gynecol 2010;116:1302–9.
3. Salonen Ros H, Lichtenstein P, Bellocco R, et al. Increased risks of circulatory
diseases in late pregnancy and puerperium. Epidemiology 2001;12:456–60.
4. Heit JA, Kobbervig CE, James AH, et al. Trends in the incidence of venous
thromboembolism during pregnancy or postpartum: a 30-year population-based study. Ann Intern Med 2005;143:697–706.
5. Greer IA. Thrombosis in pregnancy: updates in diagnosis and management.
Hematology Am Soc Hematol Educ Program 2012;2012:203–7.
6. Hellgren M. Hemostasis during normal pregnancy and puerperium. Semin
Thromb Hemost 2003;29:125–30.
7. Brenner B. Haemostatic changes in pregnancy. Thromb Res 2004;114:409–14.
8. Chan W-S, Spencer FA, Ginsberg JS. Anatomic distribution of deep vein
thrombosis in pregnancy. CMAJ 2010;182:657–60.
9. Greer IA. Prevention and management of venous thromboembolism in pregnancy. Clin Chest Med 2003;24:123–37.
10. Wik HS, Jacobsen AF, Sandvik L, Sandset PM. Prevalence and predictors
for post-thrombotic syndrome 3 to 16 years after pregnancy-related venous
thrombosis: a population-based, cross-sectional, case-control study. J Thromb
11. Pomp ER, Lenselink AM, Rosendaal FR, Doggen CJM. Pregnancy, the postpartum period and prothrombotic defects: risk of venous thrombosis in the
MEGA study. J Thromb Haemost 2008;6:632–7.
12. Marik PE, Plante LA. Venous thromboembolic disease and pregnancy. N Engl
J Med 2008;359:2025–33.
13. Jacobsen AF, Skjeldestad FE, Sandset PM. Ante- and postnatal risk factors of
venous thrombosis: a hospital-based case-control study. J Thromb Haemost
14. Virkus RA, Løkkegaard E, Lidegaard Ø, et al. Risk factors for venous thromboembolism in 1. 3 million pregnancies: a nationwide prospective cohort. PloS
15. James AH, Jamison MG, Brancazio LR, Myers ER. Venous thromboembolism
during pregnancy and the postpartum period: incidence, risk factors, and
mortality. Am J Obstet Gynecol 2006;194:1311–5.
16. Chan W-S, Lee A, Spencer FA, et al. Predicting deep venous thrombosis in
pregnancy: out in “LEFt” field? Ann Intern Med 2009;151:85–92.
17. Righini M, Jobic C, Boehlen F, et al. Predicting deep venous thrombosis in
pregnancy: external validation of the LEFT clinical prediction rule. Haemato-
18. Chan W-S, Chunilal S, Lee A, et al. A red blood cell agglutination D-dimer test to
exclude deep venous thrombosis in pregnancy. Ann Intern Med 2007;147:165–
19. Nijkeuter M, Ginsberg JS, Huisman MV. Diagnosis of deep vein thrombosis
and pulmonary embolism in pregnancy: a systematic review. J Thromb Haemost 2006;4:496–500.
20. Chan W-S, Spencer FA, Lee AY, et al. Safety of withholding anticoagulation in
pregnant women with suspected deep vein thrombosis following negative serial compression ultrasound and iliac vein imaging. CMAJ 2013;185:E194–200.
21. Dronkers CE, Srámek A, Huisman MV, Klok FA. Accurate diagnosis of iliac
vein thrombosis in pregnancy with magnetic resonance direct thrombus imaging (MRDTI). BMJ Case Rep 2016;2016. pii: bcr2016218091.
22. Ray JG, Vermeulen MJ, Bharatha A, et al. Association between MRI exposure
during pregnancy and fetal and childhood outcomes. JAMA 2016;316:952–61.
23. Royal College of Obstretricians and Gynaecologists. Thromboembolic disease
in pregnancy and the puerperium: acute management. Green-top Guideline
No. 37b. London: RCOG; 2015.
24. Barritt DW, Jordan SC. Anticoagulant drugs in the treatment of pulmonary
embolism. A controlled trial. Lancet 1960; 1(7138):1309–12.
25. Bourjeily G, Khalil H, Raker C, et al. Outcomes of negative multidetector
computed tomography with pulmonary angiography in pregnant women
suspected of pulmonary embolism. Lung 2012;190:105–11.
26. Deutsch AB, Twitty P, Downes K, Parsons MT. Assessment of the alveolar-arterial oxygen gradient as a screening test for pulmonary embolism in pregnancy.
Am J Obstet Gynecol 2010;203:373.e1–4.
27. Powrie RO, Larson L, Rosene-Montella K, et al. Alveolar-arterial oxygen
gradient in acute pulmonary embolism in pregnancy. Am J Obstet Gynecol
28. Leung AN, Bull TM, Jaeschke R, et al. American Thoracic Society documents:
an official American Thoracic Society/Society of Thoracic Radiology clinical
practice guideline--evaluation of suspected pulmonary embolism in pregnancy. Radiology 2012;262:635–46.
29. Cahill AG, Stout MJ, Macones GA, Bhalla S. Diagnosing pulmonary embolism
in pregnancy using computed-tomographic angiography or ventilation-perfu-sion. Obstet Gynecol 2009;114:124–9.
30. Bourjeily G, Paidas M, Khalil H, et al. Pulmonary embolism in pregnancy.
31. Chan WS, Ray JG, Murray S, et al. Suspected pulmonary embolism in pregnancy: clinical presentation, results of lung scanning, and subsequent maternal
and pediatric outcomes. Arch Intern Med 2002;162:1170– 5.
32. Virkus RA, Løkkegaard ECL, Bergholt T, et al. Venous thromboembolism in
pregnant and puerperal women in Denmark 1995-2005. A national cohort
study. Thromb Haemost 2011;106:304–9.
33. Kamel H, Navi BB, Sriram N, et al. Risk of a thrombotic event after the 6-week
postpartum period. N Engl J Med 2014;370:1307–15.
34. Ginsberg JS, Hirsh J, Turner DC, et al. Risks to the fetus of anticoagulant
therapy during pregnancy. Thromb Haemost 1989;61:197–203.
35. Greer IA, Nelson-Piercy C. Low-molecular-weight heparins for thromboprophylaxis and treatment of venous thromboembolism in pregnancy: a systematic review of safety and efficacy. Blood 2005;106:401–7.
36. Prandoni P, Carnovali M, Marchiori A, Galilei Investigators. Subcutaneous
adjusted-dose unfractionated heparin vs fixed-dose low-molecular-weight
heparin in the initial treatment of venous thromboembolism. Arch Intern
37. Robertson L, Jones LE. Fixed dose subcutaneous low molecular weight heparins versus adjusted dose unfractionated heparin for venous thromboembolism. Cochrane Database Syst Rev 2017;( 9):eb9;2:CD001100.
38. Costantino G, Ceriani E, Rusconi AM, et al. Bleeding risk during treatment of
acute thrombotic events with subcutaneous LMWH compared to intravenous
unfractionated heparin; a systematic review. PloS One 2012;7:e44553.
39. Warkentin TE, Levine MN, Hirsh J, et al. Heparin-induced thrombocytopenia
in patients treated with low-molecular-weight heparin or unfractionated heparin. N Engl J Med 1995;332:1330–5.
40. Junqueira DRG, Perini E, Penholati RRM, Carvalho MG. Unfractionated
heparin versus low molecular weight heparin for avoiding heparin-induced
thrombocytopenia in postoperative patients. Cochrane Database Syst Rev
41. Bates SM, Greer IA, Middeldorp S, et al. VTE, thrombophilia, antithrombotic
therapy, and pregnancy. Chest 2012;141:e691S–e736S.
42. Clark NP, Delate T, Witt DM, et al. A descriptive evaluation of unfractionated
heparin use during pregnancy. J Thromb Thrombolysis 2009;27:267–73.
43. Clark NP, Delate T, Cleary SJ, Witt DM. Analysis of unfractionated heparin
dose requirements to target therapeutic anti-Xa intensity during pregnancy.
Thromb Res 2010;125:402–5.
44. Jacobsen AF, Qvigstad E, Sandset PM. Low molecular weight heparin (
dalteparin) for the treatment of venous thromboembolism in pregnancy. BJOG
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