Open AccessUse of high intensity adjusted dose low molecular weight heparin in women with mechanical heart valves during pregnancy: a single-center experience
Author(s) -
John A. Quinn,
Kate von Klemperer,
R. J. Brooks,
Donald Peebles,
Fiona Walker,
Hannah Cohen
Publication year - 2009
Publication title -
haematologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.782
H-Index - 142
eISSN - 1592-8721
pISSN - 0390-6078
DOI - 10.3324/haematol.2008.002840
Subject(s) - medicine , pregnancy , low molecular weight heparin , mechanical heart , heparin , thrombosis , prospective cohort study , obstetrics , aspirin , gestation , single center , surgery , genetics , biology
The use of standard dose low molecular weight heparin (LMWH) to anticoagulate women with mechanical valves in pregnancy is associated with morbidity and mortality. We conducted a prospective audit of the use of adjusted dose high intensity LMWH in 12 pregnancies in 11 women with prosthetic heart valves. LMWH +/- low-dose aspirin was started at therapeutic-dose with monitoring of anti-Xa levels to achieve a target level of 1.0-1.2 IU/mL (0.8-1.2 in the first 3/12 pregnancies). This necessitated a mean increase in the dose of LMWH of 54.4% (SD+/-33.2) over initial dose. Eleven of 12 pregnancies resulted in live births, with one intrauterine fetal death at 37 weeks. One non-fatal valve thrombosis occurred at 26 weeks gestation associated with subtherapeutic anti-Xa levels. Three patients experienced major bleeding. This regime provides a therapeutic option for women with mechanical heart valves during pregnancy, provided anti-Xa levels are kept within the target range. These patients require close surveillance for bleeding and thrombotic complications within a multi-disciplinary setting.