Pregnancy managed by unfractionated heparin after mechanical aortic valve replacement.

Pregnancy after mechanical valve replacement involves high risk. Maternal valve thrombosis and hemorrhagic complications are associated with lethal outcomes; therefore, strict anticoagulant therapy is needed. Our patient was 26-year-old primiparous woman. She had undergone aortic valve replacement with a mechanical valve at 4 years of age and had used warfarin 3 mg per day since then. Because of her desire for a baby, she stopped warfarin and conceived spontaneously. She was referred to our hospital. After being informed of her choices, unfractionated heparin (UFH) administration was started. She experienced mild heart failure with sacroiliitis, bacteremia, and hematuria during pregnancy. She delivered her newborn at 37 weeks. Blood loss at delivery was 220 g. Administration of UFH was restarted 4 h after delivery and 3 mg of warfarin was administered from postpartum day (PPD) 6. Hemostatic suturing was required for vaginal bleeding on PPD7. A therapeutic dose of warfarin was achieved on PPD9. Although warfarin use is recommended as anticoagulant therapy for pregnant woman with mechanical valves, the safety and efficacy of UFH have not yet been clarified because of its limited use. More cases are needed to clarify this.