Low-intensityanticoagulation therapy in the pregnant women with mechanical heart valves:a report with56 cases

：Objective To evaluatethe method of low-intensity anticoagulation therapy in the pregnant women who had receivedmechanical heart valve replacemant, and the effects of warfarin on the pregnant women andtheir fetus. Methods This retrospective study involved 56 pregnant women( 61pregnancies)who had received mechanical heart valve replacement.Their pregnant status,delivery, and anticoagulation therapy were observed and followed-up between May 1986 andNovember 2009 at West China Hospital of Sichuan University. Results All patients took oralanticoagulant (warfarin) throughout pregnancy. The dose of domestic warfarin was ( 3.02 ±0.85 ) mg/d ( in 42 cases), and the dose of imported warfarin was (2.84 ± 0.57 )mg/d (in14 cases). The mean INR value of 401 samples from patients was 1.67 ±0.58. Nothromboembolism or major hemorrhagic complications occurred. Minor bleeding occurred in 11pregnancies. Forty-seven patients had term delivery, 7 had premature birth, 6 hadspontaneous abortion, and 1 had intrauterine fetal death. Six newborns were born with lowbirth weight (2.3 ± 0. 5 ) kg, and no abnormal fetus was observed. Conclusion Thelow-intensity anticoagulation therapy with warfarin (at a dose of less than 5 mg/d) and aINR target of 1.5 to 2.0 was safe and convenient for the pregnant women,who had receivedmechanical heart valve replacement. The abnormalities rate of fetus was low.