Low-dose warfarin maternal anticoagulation and fetal warfarin syndrome

BMJ Case Rep. 2018 Apr 7:2018:bcr2017223159. doi: 10.1136/bcr-2017-223159.

Abstract

Fetuses exposed to warfarin during pregnancy are at an increased risk of developing an embryopathy known as fetal warfarin syndrome or warfarin embryopathy. The most consistent anomalies are nasal hypoplasia and stippling of vertebrae or bony epiphyses. Management of pregnant patients on anticoagulation is challenging. Current guidelines suggest the use of warfarin if the therapeutic dose is ≤5 mg/day. We report the case of a newborn with signs of warfarin embryopathy born from a mother anticoagulated with warfarin due to mechanical mitral and aortic heart valves. Warfarin was required at the dose of 5 mg/day and was withheld without medical advice between weeks 8 and 10 with no other anticoagulation. The newborn presented with skeletal abnormalities and a ventricular septal defect that have not required specific treatment during the first year of life. Low-dose warfarin is associated with a lower risk of warfarin-related fetopathy but the risk of embryopathy seems unchanged.

Keywords: drugs: obstetrics and gynaecology; paediatrics (drugs and medicines); unwanted effects / adverse reactions; valvar diseases; warfarin therapy.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Drug-Induced / diagnosis*
  • Abnormalities, Drug-Induced / physiopathology
  • Adult
  • Anticoagulants / administration & dosage*
  • Anticoagulants / adverse effects*
  • Congenital Abnormalities
  • Female
  • Heart Valve Prosthesis
  • Humans
  • Infant, Newborn
  • Male
  • Nasal Bone / abnormalities*
  • Nasal Bone / physiopathology
  • Nasal Cartilages / abnormalities
  • Pregnancy
  • Pregnancy Complications, Cardiovascular / drug therapy*
  • Pregnancy Complications, Cardiovascular / physiopathology
  • Treatment Outcome
  • Warfarin / administration & dosage*
  • Warfarin / adverse effects*

Substances

  • Anticoagulants
  • Warfarin

Supplementary concepts

  • Nasal Bones, Absence of
  • Warfarin syndrome