Low-dose maternal warfarin intake resulting in fetal warfarin syndrome: In search for a safe anticoagulant regimen during pregnancy.

Abstract

Fetal exposure to maternal ingestion of warfarin is known to produce certain dysmorphic features in the neonate, known as fetal warfarin syndrome (FWS). There is a general consensus that maternal intake of warfarin at a daily dose of 5 mg or less is safe both for the infant and the mother. We report four cases of FWS born to mothers with rheumatic heart disease on warfarin prophylaxis during pregnancy at a dose less than 5 mg/day. Along with typical facial features of FWS and multiple epiphyseal stippling in skeletal x-ray, Case 1 had Dandy-Walker malformation and Case 2 had laryngo-tracheomalacia and patent ductus arteriosus. We emphasize the need for optimizing the choice and dosage schedule of anticoagulants during pregnancy, least harmful for the mother and her developing fetus.