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

Birth Defects Res A Clin Mol Teratol. 2016 Feb;106(2):142-7. doi: 10.1002/bdra.23435. Epub 2015 Sep 21.

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusion: We emphasize the need for optimizing the choice and dosage schedule of anticoagulants during pregnancy, least harmful for the mother and her developing fetus.

Keywords: anticoagulants; fetal warfarin syndrome; heart valve prosthesis; neonate; pregnancy; warfarin.

MeSH terms

  • Abnormalities, Drug-Induced / pathology*
  • Abnormalities, Multiple / chemically induced
  • Adult
  • Anticoagulants / adverse effects*
  • Dandy-Walker Syndrome / chemically induced
  • Ductus Arteriosus, Patent / chemically induced
  • Female
  • Heart Valve Prosthesis
  • Humans
  • Nasal Bone / abnormalities*
  • Nasal Bone / pathology
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Rheumatic Heart Disease
  • Warfarin / adverse effects*

Substances

  • Anticoagulants
  • Warfarin

Supplementary concepts

  • Warfarin syndrome