Pregnancy outcome in women with mechanical prosthetic heart valvesat their first trimester of pregnancy treated with unfractionated heparin (UFH) or enoxaparin: A randomized clinical trial.

Pregnancy increases the risks of thromboembolism for the mother and fetus in patients with mechanical heart valves. The results of some studies have indicated that low molecular weight heparin (LMWH), in comparison with unfractionated heparin (UFH), leads to a lower incidence rate of thrombocytopenia and a decrease in bleeding. The present randomized clinical trial involved 31 pregnant women with mechanical heart valves at their first trimester (0-14 weeks) of pregnancy.