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Warfarin Pregnancy and Breastfeeding Warnings

Warfarin is also known as: Coumadin, Jantoven

Medically reviewed by Last updated on Sep 6, 2021.

Warfarin Pregnancy Warnings

Use is contraindicated.

AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned

Risk Summary: Use is contraindicated in pregnant women except those with mechanical heart valves, who are at high risk of thromboembolism, and for whom the benefits of this drug may outweigh the risks.

-Adequate methods of contraception should be used during treatment and for at least 1 month after the final dose.
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.

Animal studies have revealed evidence of teratogenicity. In humans, exposure to this drug during the first trimester of pregnancy caused a pattern of congenital malformations (embryopathy and fetotoxicity) in about 5% of exposed offspring. Intellectual disability, blindness, schizencephaly, microcephaly, hydrocephalus, and other adverse pregnancy outcomes have been reported following exposure to this drug during the second and third trimesters. Fatal fetal hemorrhage and an increased risk of spontaneous abortion and fetal mortality have also occurred due to exposure to this drug during pregnancy. There are no controlled data in human pregnancy

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

See references

Warfarin Breastfeeding Warnings

Use is generally considered acceptable; benefit to mother should outweigh risk to the infant.

Excreted into human milk: Yes (in small amounts)

-This drug has been used without apparent harmful effects in the nursing infant.
-Effects in premature infants have not been evaluated.

See references

References for pregnancy information

  1. Cerner Multum, Inc. "Australian Product Information." O 0
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. "Product Information. Coumadin (warfarin)." DuPont Pharmaceuticals, Wilmington, DE.

References for breastfeeding information

  1. United States National Library of Medicine "Toxnet. Toxicology Data Network. Available from: URL:" ([cited 2013 -]):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. "Product Information. Coumadin (warfarin)." DuPont Pharmaceuticals, Wilmington, DE.
  4. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.