0275: Can we use enoxaparin in pregnant women with mechanical heart valves?

Abstract

No definitive recommendation is available concerning optimal antithrombotic therapy in pregnant women with a mechanical heart valve. The purpose of the current study was to evaluate the clinical results of Enoxaparin treatment with respect to pregnancy outcome and maternal complications. From 2003 to 2012, 50 pregnancies were reviewed in 42 women. The valve replaced was mitral (n=28), aortic (n=4), and both (n=10). Enoxaparin (100 U/kg, twice daily) was used in 25 pregnancies between 6 and 12 weeks of gestation and close-to-term only, and coumarin derivatives were used at other times. 25 pregnant women treated with coumarin derivatives throughout pregnancy were compared to evaluate the safety and efficacy of Enoxaparin. 4 mothers developed mitral valve thrombosis (2 were on LMWH and 4 on coumarin). Hemorrhagic complications occurred in 5 patients, 2 of whom required transfusion. There was 1 maternal death from valve thrombosis (in the Enoxaparin-treated group). The incidence of maternal complications was similar between the 2 groups. 2 cases ended in early miscarriage, and 5 cases ended in intrauterine fetal death. The frequencies of fetal complications, live born and healthy babies were similar between the 2 groups. Regarding the efficacy and safety of antithrombotic treatment in pregnant women with prosthetic heart valves, Enoxaparin treatment during the first trimester is an acceptable regimen. These patients require close surveillance for bleeding and thrombotic complications within a multidisciplinary setting