Analysis of anticoagulant therapy by unfractionated heparin during pregnancy after mechanical valve replacement

Abstract

Background: Consensus has not been reached about the anticoagulant therapy to be used during pregnancy after mechanical valve replacement. Warfarin is a fetal toxicant, so we retrospectively examined anticoagulant therapy using unfractionated heparin. Methods and Results: Pregnancy after mechanical valve replacement occurred in 25 cases between 1983 and 2011. Targeted therapy using unfractionated heparin was administered in 9 pregnancies, which were divided into 3 groups: Group I received subcutaneous administration of heparin and APTT was measured twice weekly; Group II received heparin by constant rate infusion (CRI) and APTT was measured twice weekly; Group III received CRI of heparin and APTT was measured daily. Maternal complications consisted of valve thrombosis and perinatal bleeding in 1 pregnancy (Group I), intracranial hemorrhage in 2 pregnancies (Group II), and valve thrombosis and perinatal bleeding in 1 pregnancy (Group III). Two infants died in the neonatal period. Conclusions: Each group showed a high rate of maternal complications, so a review of current anticoagulant treatment strategies is necessary.