Facial Abnormalities Following Warfarin Exposure In Utero

Abstract

In low- and middle-income countries like Uganda, rheumatic heart disease (RHD) remains a leading indication for valve replacement, disproportionately affecting young women of reproductive age. Pregnancy in women with mechanical heart valves (MHVs) poses significant challenges due to the need for anticoagulation therapy, balancing maternal thrombotic risk against fetal safety. Warfarin, though highly effective in preventing valve thrombosis, carries teratogenic risks, including warfarin embryopathy, particularly when used during the first trimester. We report a case of a 21-year-old woman with RHD, who underwent mitral valve replacement with a mechanical prosthesis in 2021. She was poorly compliant with follow-up appointments, had a low time in the therapeutic range of 60% (target is at least 70%), and had thrombotic complications, including prosthetic valve thrombosis and an ischemic stroke. Her pregnancy was discovered at 16 weeks gestation, well beyond the critical embryogenesis period. She remained on warfarin throughout pregnancy until 36 weeks, when she was switched to low-molecular-weight heparin before delivery by elective caesarean section. A baby girl was born with features consistent with warfarin embryopathy, including saddle nose deformity, respiratory distress, and congenital heart defects. This case underscores the teratogenic risks of warfarin and highlights the challenges of anticoagulation management in pregnant women with MHVs. While warfarin remains the most effective anticoagulant for maternal safety, its fetal risks necessitate individualized anticoagulation strategies. The case reinforces the importance of preconception counselling, contraception planning, and shared decision-making regarding valve selection and anticoagulation in women of reproductive age with MHVs. Further research is needed to optimize anticoagulation management, particularly in developing countries where RHD remains a major burden.