Skip to main content
    • Aa
    • Aa



Mechanical heart valves pose a particular challenge in pregnancy, as the primary agent used to prevent valve thrombosis, coumadin (warfarin), is a known teratogen. Alternatives to coumadin, such as unfractionated heparin (UFH) and low-molecular weight heparin (LMWH) are safer for the fetus, particularly during the first trimester of pregnancy, but expose the mother to potential valve failure. This review will examine these controversies and the complex literature regarding management in pregnancy.

Corresponding author
Cynthia Maxwell, Mount Sinai Hospital, Department of Obstetrics and Gynaecology, 600 University Avenue, Toronto ON, M5G 1X5Canada.
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

2I Goldsmith , AGG Turpie , GYH Lip . ABC of antithrombotic therapy. Valvuar heart disease and prosthetic heart valves. Br Med J 2002; 325: 1228–231.

3DN Salem , PD Stein , A Al-Ahmad , HI Bussey , D Horskotte , N Miller Antithrombotic therapy in valvular heart disease – native and prosthetic: The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126: 457–82.

4EM Baudet , V Puel , JT McBride , JP Grimaud , F Roques , F Clerc Long-term results of valve replacement with the St. Jude Medical prosthesis. J Thorac Cardiovasc Surg 1995; 109: 858–70.

5VO Bjork , A Henze . Management of thrombo-embolism after aortic valve replacement with the Bjork-Shiley tilting disc valve: medicamental prevention with dicumarol in comparison with dipyrimidamole-acetylsalicylic acid; surgical treatment of prosthetic thrombosis. Scand J Thorac Cardiovasc Surg 1975; 9: 183–91.

6JC Cappelleri , LD Fiore , MT Brophy , D Deykin , J Lau . Efficacy and safety of combined anticoagulant and antiplatelet therapy versus anticoagulant monotherapy after mechanical heart valve replacement: a meta analysis. Am Heart J 1995; 130: 547–52.

7D Born , EE Martinez , PAM Almeida , DV Santos , ACC Carvalho , AF Moron . Pregnancy in patients with prosthetic heart valves: the effect of anticoagulation on mother, fetus and neonate. Am Heart J 1992; 124: 413–17.

8E Sbarouni , CM Oakley . Outcome of pregnancy in women with valve prostheses. Br Heart J 1994; 71: 196201.

11CE Denbow , L Matadial , S Sivapragasam , H Spencer . Pregnancy in patients after homograft cardiac valve replacement. Chest 1983; 83: 540–42.

12A Dore , J Somerville . Pregnancy in patients with pulmonary autograft valve replacement. Eur Heart J 1997; 18: 1659–62.

16RB Gherman , TM Goodwin , B Leung , JD Byrne , R Hethumumi , M Montoro . Incidence, clinical characteristics, and timing of objectively diagnosed venous thromboembolism during pregnancy. Obstet Gynecol 1999; 94: 730–34.

17JG Ray , WS Chan . Deep vein thrombosis during pregnancy and the puerperium: a meta-analysis of the period of risk and the leg of presentation. Obstet Gynecol Surv 1999; 54: 265–71.

19JAG Hall , RM Paul , KM Wilson . Maternal and fetal sequelae of anticoagulation during pregnancy. Am J Med 1980; 68: 122140.

20WS Chan , S Anand , JS Ginsberg . Anticoagulation of pregnant women with mechanical heart valves: a systematic review of the literature. Arch Int Med 2000; 160: 191–96.

21F Robin , F Lecuru , P Desfeux , B Boucaya , R Taurelle . Anticoagualation therapy in pregnancy. Eur J Obstet Gynecol Reprod Biol 1999; 83: 171–77.

23JS Ginsberg , G Kowalchuk , J Hirsh , P Brill-Edwards , R Burrows . Heparin therapy during pregnancy: risk to the fetus and mother. Arch Int Med 1989; 149: 2233–36.

24Y Shapira , A Sagie , A Battler . Low-molecular-weight heparin for the treatment of patients with mechanical heart valves. Clin Cardiol 2002; 25: 323–27.

25JB Groce . “Bridging” therapy with low molecular weight heparin in pregnant patients and patients with mechanical prosthetic heart valves. J Thromb Thrombolysis 2003; 16: 7982.

26PD Stein , JS Alpert , HI Bussey , JE Dalen , AGG Turpie . Antithrombotic therapy in patients with mechanical and bioprosthetic heart valves. Chest 2001; 119: 220–27.

29SM Bates , IA Greer , J Hirsh , JS Ginsberg . Conference on antithrombotic and thrombolytic therapy use of antithrombotic agents during pregnancy – The seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126: 627–44.

30J Lepercq , J Conard , A Borel-Derlon , JY Darmon , O Boudignat , C Francoual Venous thromboembolism during pregnancy: a retrospective study of enoxaparin safety in 624 pregnancies. BJOG 2001; 108: 1134–140.

31F Forestier , F Daffos , M Capella-Pavlovsky . Low molecular weight heparin (PK 10169) does not cross the placenta during the second trimester of pregnancy: study by direct fetal blood sampling under ultrasound. Thromb Res 1984; 34: 557–60.

34C Nelson-Piercy , EA Letsky , M de Swiet . Low molecular weight heparin for obstetric thromboprophylaxis: experience of sixty-nine pregnancies in sixty-one women at high risk. Am J Obstet Gynecol 1997; 176: 10621068.

35TE Warkentin , MN Levine , J Hirsh , P Horsewood , RS Roberts , M Gent Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin. NEJM 1995; 332:1330–336.

36HW de Valk , JD Banga , JW Wester , CB Brouwer , MW van Hessen , OJ Meuwissen Comparing subcutaneous danaparoid with intravenous unfractionated heparin for the treatment of venous thromboembolism: a randomized controlled trial. Ann Intern Med 1995; 123: 19.

39TC Dahlman . Osteoporotic fractures and the recurrence of thromboembolism during pregnancy and the puerperium in 184 women undergoing thromboprophylaxis with heparin. Am J Obstet Gynecol 1993; 168: 1265–270.

43ID Bradbrook , HN Magnani , HC Moelker , PJ Morrison , J Robinson , HJ Rogers ORG 10172: a low molecular weight heparinoid anticoagulant with a long half life in man. Br J Clin Pharmacol 1987; 23: 667–75.

46E Holmer , K Kurachi , G Soderstrom . The molecular-weight dependence of the rate-enhancing effect of heparin on the inhibition of thrombin, factor Xa, factor IXa, factor XIa, factor XIIa and kallikrein by antithrombin. Biochem J 1981; 193: 395400.

48L Bara , E Billaud , G Gramond , A Kher , M Samama . Comparative pharmacokinetics of low molecular weight heparin and unfractionated heparin after intravenous and subcutaneous administration. Thromb Res 1985; 39: 631–36.

55JS Ginsberg , WS Chan , SM Bates , S Kaatz . Anticoagulation of pregnant women with mechanical heart valves. Arch Intern Med 2003; 163: 694–98.

56TF Imperiale , AS Petrulis . A meta-analysis of low-dose aspirin for prevention of pregnancy-induced hypertensive disease. JAMA 1991; 266: 260–64.

57U Elkayam , H Singh , A Irani , MW Akhter . Anticoagulation in Pregnant Women With Prosthetic Heart Valves. J Cardiovasc Pharmacol Ther 2004; 9: 107–15.

58JA Rowan , LM McCowan , PJ Raudkivi , RA North . Enoxaparin treatment in women with mechanical heart valves during pregnancy. Am J Obstet Gynecol 2001; 185: 633–37.

61R Bauersachs , E Lindhoff-Last . Anticoagulation of pregnant women with mechanical heart valves using low-molecular-weight heparin. Arch Intern Med 2003; 163: 2788–789.

62P Behrendt , B Schwartzkopff , S Perings , A Gerhardt , RB Zotz , AB Stauer . Successful thrombolysis of St. Jude Medical Aortic Prosthesis with tissue-type plasminogen activator in a pregnant woman: A case report. Cardiol Rev 2002; 10: 349–53.

63J Ellison , AJ Thomson , ID Walker , IA Greer . Use of enoxaparin in a pregnant woman with a mechanical heart valve prosthesis. BJOG 2001; 108: 757–59.

66O Lev-Ran , A Kramer , J Gurevitch , I Shapira , R Mohr . Low-molecular weight heparin for prosthetic heart valves: treatment failure. Ann Thoracic Surg 2000; 69: 264–66.

67RG Leyh , S Fischer , A Ruhparwar , A Haverich . Anticoagulation for prosthetic heart valves during pregnancy: Is low-molecular-weight heparin an alternative? Eur J Cardiothorac Surg 2002; 21; 577–79.

71D Oles , R Berryessa , K Campbell , MA Bhatti . Emergency redo mitral valve replacement in a 27-year-old pregnant female with a clotted prosthetic mitral valve, preoperative fetal demise and postoperative ventricular assist device: a case report. Perfusion 2001; 16: 159–64.

72N Roberts , D Ross , S Flint , R Arya , M Blott . Thromboembolism in pregnant women with mechanical prosthetic heart valves anticoagulated with low molecular-weight heparin. BJOG 2001; 108: 327–29.

73MA Geelani , S Singh , A Verma , A Nagesh , V Betigeri , M Nigam . Anticoagulation in patients with mechanical valves during pregnancy. Asian Cardiovasc Thorac Ann 2005; 13: 3033.

75RO Bonow , BA Carabello , K Chatterjee , AC Jr de Leon , DP Faxon , MD Freed ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. (Writing Committee to revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation 2006; 114: e84231.

76WA Evans , SA Laifer , TJ McNanley , A Ruzycky . Management of Thromboembolic Disease Associated With Pregnancy. J Matern Fetal Med 1997; 6: 2127.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Fetal and Maternal Medicine Review
  • ISSN: 0965-5395
  • EISSN: 1469-5065
  • URL: /core/journals/fetal-and-maternal-medicine-review
Please enter your name
Please enter a valid email address
Who would you like to send this to? *