Low-Dose Aspirin Use During Breastfeeding

Introduction to Aspirin Safety

The American College of Chest Physicians recommends continuing low-dose aspirin during breastfeeding for lactating women using it for vascular indications, with a Grade 2C recommendation 1, 2, 3
Low-dose aspirin (<100 mg/day) has a favorable safety profile, with no significant effects on neonatal platelet function, suggesting minimal infant exposure 1, 2, 3
A prospective study of 15 breastfeeding mothers taking aspirin therapy documented no negative effects on infants 1, 2, 3

High doses of aspirin (>100 mg/day) pose real risks, including metabolic acidosis, platelet dysfunction, gastrointestinal bleeding, and theoretically Reye syndrome in nursing infants exposed to high maternal doses 1, 2, 3
Salicylates are excreted into breast milk in proportion to maternal dose 1, 2, 3

Aspirin is a polar, acidic drug that is poorly lipid soluble and highly protein-bound (>90%), limiting transfer into breast milk 1, 2, 3

If the aspirin dose is ≤100 mg/day, breastfeeding can continue without interruption 1, 2, 3
For vascular indications, low-dose aspirin is specifically recommended during lactation 1, 2, 3
If high doses are required for pain or inflammation, alternative NSAIDs like ibuprofen may be considered, with extensive lactation safety data available 4

Infants of mothers on low-dose aspirin should be monitored for unusual bruising or bleeding, although this is not expected at low doses 1, 2, 3
The theoretical risk of Reye syndrome has never been documented in breastfed infants of mothers taking low-dose aspirin and remains purely theoretical even at higher maternal doses 1, 2, 3

Women who used low‑dose aspirin (≤100 mg/day) during pregnancy for autoimmune or hypertensive disorders (e.g., systemic lupus erythematosus, antiphospholipid syndrome, or preeclampsia prevention) may safely continue the medication while breastfeeding, with no reported adverse infant outcomes. [5][6]