aspirin and breastfeeding

Last edited 07/2023 and last reviewed 08/2023

Aspirin and Breastfeeding

Limited data and pharmacokinetics indicate that low dose aspirin (defined here as 75 – 100mg daily) passes into breast milk in small amounts (1):

• there have been no adverse events described in infants exposed to aspirin via breast milk when used as an antiplatelet agent ) (1,2)
• however, the data available for the use of aspirin whilst breastfeeding are limited and therefore it should be used with caution. Infants exposed to aspirin via breastmilk should be monitored for side effects described in children when used in directly
• Limited published information on low-dose aspirin (defined here as 75mg to 150mg daily) shows milk levels are negligible (3)
  
  
• is unknown whether the small amounts of aspirin present in breast milk following an antiplatelet dose could cause Reye’s syndrome in a breastfed infant
• Reye’s syndrome is a disorder characterised by acute encephalopathy and fatty degeneration of the liver
• occurs most commonly in young children although cases have been seen in patients over the age of 12
• many factors may be involved in its aetiology but it typically occurs after a viral infection such as chickenpox or influenza and may be precipitated by a chemical trigger
• a definitive dose-related relationship between aspirin and Reye’s syndrome has not been established (2)
• is unknown whether the small amounts present in breast milk following an antiplatelet dose would be clinically significant
• to minimise the risk, breastfeeding should be withheld if the infant develops a fever, or consider temporarily discontinuing the aspirin if clinically justified
  • is unknown whether the negligible amounts of aspirin present in breast milk following an antiplatelet dose could cause Reye’s syndrome in a breastfed infant (3)
• limited data and pharmacokinetics indicate that low dose aspirin (defined here as 75 – 100mg daily) passes into breast milk in small amounts
  
  
• there have been no adverse events described in infants exposed to aspirin via breast milk when used as an antiplatelet agent
• however, the data available for the use of aspirin whilst breastfeeding are limited and therefore it should be used with caution. Infants exposed to aspirin via breastmilk should be monitored for side effects described in children when used in directly
  
  
• is unknown whether the small amounts of aspirin present in breast milk following an antiplatelet dose could cause Reye’s syndrome in a breastfed infant
• to minimise the risk, breastfeeding should be withheld if the infant develops a fever, or consider temporarily discontinuing the aspirin if clinically justified

Notes:

• infants exposed to aspirin via breastmilk should be monitored for adverse effects described with therapeutic doses of aspirin when used in children directly
• in particular, signs of bruising and bleeding, which may be prolonged (7–10 days)
• other possible adverse effects include tachycardia, hypersensitivity reactions such as rash, urticaria, dyspnoea, severe bronchospasm, angioedema, increased bleeding during or after surgery, and thrombocytopenia

Reference:

• NHS Speclialist Pharmacy Service (September 2020). Can low dose aspirin be used in breastfeeding mothers as an antiplatelet agent?
• Glasgow JF. Reye’s syndrome - The case for a causal link with aspirin. Drug Saf 2006;29:1111–1121.
• NHS Specialist Pharmacy Service (July 2023). Using antiplatelet medicines during breastfeeding