PREGNANCY IN PATIENTS WITH VALVULAR PROSTHESES - RETROSPECTIVE COOPERATIVE STUDY IN FRANCE (155 CASES)

The maternal outcome in the group of 108 mechanical prostheses was complicated by 16 thromboembolic events (TE) including 10 prosthetic valve thromboses which required emergency valve replacement in 4 cases, 6 systemic TE in 13 mitral, 2 aortic and 1 pulmonary mechanical prostheses. The TE were four times more frequent in patients on heparin than in those on oral anticoagulants. There were 4 deaths, 3 among the 10 prosthetic valve thromboses (one reoperation, two sudden deaths). Seven of the 74 bioprostheses were reoperated for degeneration on average 5.9 years after the initial operation but there were no deaths or TE. The outcome of pregnancy was 99 children (63 %), 49 of which were born to mothers with mechanical prostheses (53 %) and 50 to mothers with bioprostheses (80 %) (p < 0.001). Seven of the children were born prematurely, all mothers being on anticoagulant therapy. The birth weight was over 400 grammes heavier (3 kg versus 2.6 kg) in the bioprosthesis group (p < 0.05). The 20 spontaneous abortions (13 %) were more common in patients on anticoagulants (17 %) than in those without (2 %) (p < 0.0.2). Congenital defects due to oral anticoagulants were rare (one certain case). There was one case of phocomelia, an abnormality which has never been described in this context. The 36 remaining pregnancies were still deaths (N = 5), abortion due to maternal death (N = 4), maternal complications (N = 8), therapeutic (N = 9) or voluntary abortions (N = 10) (28 mechanical and 8 bioprostheses). Pregnancy with a valvular prosthesis under anticoagulant therapy is dangerous for the mother and risky for the child. The therapeutic indications in women of childbearing age should be born in mind. Conservative percutaneous or surgical techniques should be preferred in mitral valve disease. In valve replacement, a mechanical prosthesis is the valve of choice in the aortic position where the risk of thrombosis is low. In mitral valve disease, mechanical prostheses are proposed in patients with mitral fibrillation or in women who already have a family, whilst advising against further pregnancy. In women without children in sinus rhythm, a bioprosthesis should be considered because the risk of thrombosis of mechanical prostheses was 40 times higher in our series, which must be taken into consideration together with the risk of reoperation in the medium term with bioprostheses. Accelerated degenerescence was only observed in a limited number of cases in this series. In women with a mechanical prosthesis at the start of pregnancy, heparin therapy should be prescribed for the shortest possible period because there, TE are 4 times more common. Heparin therapy is reduced to the two difficult periods situated from the 6th to the 12th week (coumarin-induced embryonopathies) and during the last two weeks (haemorrhage at childbirth and in the postpartum period). All these propositions are a choice of << the lesser evil >>. There are practically no large, prospective, randomised series in the medical literature and pregnancy of women with mechanical prostheses remains a dangerous undertaking during which the risk of TE is ten times greater than the usual risk.