Acenocoumarol and pregnancy outcome in a patient with mitral valve prosthesis: a case report

There is considerable controversy concerning the correct management of gravid patients with cardiac valve prostheses.

We describe the uneventful course of pregnancy and delivery in a pregnant patient with a mechanical heart valve receiving anticoagulation treatment. A 35-year-old primigravida received anticoagulation throughout pregnancy because of mitral valve replacement at the age of 16 due to rheumatic disease. The antithrombotic regimen used was acenocoumarol (coumarin derivative) 2 mg/day throughout the 2nd and 3rd trimesters of pregnancy with replacement of acenocoumarol by enoxaparin sodium 60 mg twice daily (low-molecular-weight heparin - LMWH) in the 1st trimester during weeks 7-12. International normalization ratio (INR) values were kept above 2.5. At 36 weeks of gestation, acenocoumarol was substituted with unfractionated heparin and 2 days later the patient entered spontaneous premature labor and was emergently delivered via cesarean section (INR = 1.4). A healthy male infant was born 2,560 g, Apgar scores 8 and 10 at 1 and 5 min. No coumarin embryopathy was revealed and the postoperative course of the mother was uneventful.

Even though the use of acenocoumarol throughout pregnancy replaced by LMWH in the 1st trimester was proven safe and efficacious in this case report, large randomized controlled studies are still needed to make definitive recommendations about optimal antithrombotic therapy in pregnant patients with mechanical heart valves.