The Basics
What is Aspirin?
Used to treat fever, pain, and inflammation in the body; also used to prevent blood clots, and to reduce the risk of strokes and heart attacks.
Brand names for Aspirin
Bayer
How Aspirin is classified
Analgesic Agents, Nonsteroidal Antiinflammatory Agents, Platelet Aggregation Inhibitors
Aspirin During Pregnancy
Aspirin pregnancy category
Category DNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Aspirin while pregnant
Guidelines recommend low-dose aspirin prophylaxis (e.g., 81 mg/day) in women at high risk of preeclampsia; initiation should be between 12 and 28 weeks gestation (optimally before 16 weeks) and continued until delivery.-Use of chronic or intermittent high doses should be avoided, especially during the third trimester of pregnancy as it may cause premature closure of the ductus arteriosus.In animals, prostaglandin synthesis inhibitors have been shown to increase pre and post-implantation loss and embryo-fetal lethality. Epidemiologic studies suggest increased risk of miscarriage, cardiac malformations, and gastroschisis when used early in pregnancy; the absolute risk of cardiovascular malformations increased from less than 1% to up to approximately 1.5%. The risk is believed to increase with dose and duration of therapy.Aspirin (acetylsalicylic acid) is a NSAID that inhibits cyclooxygenase (COX) isoenzymes 1 and 2. The effect on COX isoenzymes is dose-dependent with lower doses (60 to 150 mg) inhibiting platelet synthesis while higher doses results in inhibition of both COX-1 and COX-2 blocking all prostaglandin production. Low-dose aspirin has been used during pregnancy to prevent or delay the onset of preeclampsia. Daily low-dose aspirin has been shown to be associated with a low likelihood of serious maternal, or fetal complications. Guidelines should be consulted for specific use.During the third trimester of pregnancy, administration of COX-1 and COX-2 blocking nonsteroidal anti-inflammatory drugs (NSAIDs) may cause premature closure of the fetal ductus arteriosus, oligohydramnios, fetal renal impairment, pulmonary hypertension, and prolongation of bleeding time. There are no controlled data in human pregnancy.Administration during labor and delivery is not recommended as the onset of labor may be delayed and duration increased with greater bleeding tendency in mother and child.A study of the use of low-dose aspirin (60 mg per day) to prevent and treat preeclampsia in 9364 pregnant women (the Collaborative Low-dose Aspirin Study in Pregnancy–CLASP) did not support routine prophylactic or therapeutic administration of antiplatelet therapy in pregnancy to all women at increased risk of preeclampsia or IUGR. In that study, no excess of intraventricular hemorrhage, neonatal bleeds, or mortality attributable to bleeding were observed. The investigators did identify a possible role for low-dose aspirin in the treatment of early-onset preeclampsia severe enough to need very preterm delivery.
Taking Aspirin While Breastfeeding
What are recommendations for lactation if you're taking Aspirin?
After aspirin ingestion, salicylic acid is excreted into breastmilk, with higher doses resulting in disproportionately higher milk levels. Long-term, high-dose maternal aspirin ingestion probably caused metabolic acidosis in one breastfed infant. Reye’s syndrome is associated with aspirin administration to infants with viral infections, but the risk of Reye’s syndrome from salicylate in breastmilk is unknown. An alternate drug is preferred over continuous high-dose, aspirin therapy. After daily low-dose aspiring (75 to 325 mg daily), no aspirin is excreted into breastmilk and salicylate levels are low. Daily low-dose aspirin therapy may be considered as an antiplatelet drug for use in breastfeeding women.[1][2][3]. If it is used by a nursing mother, monitor the infant for bruising and bleeding.
Maternal / infant drug levels
After aspirin ingestion, salicylic acid is excreted into breastmilk, with higher doses resulting in disproportionately higher milk levels. Long-term, high-dose maternal aspirin ingestion probably caused metabolic acidosis in one breastfed infant. Reye’s syndrome is associated with aspirin administration to infants with viral infections, but the risk of Reye’s syndrome from salicylate in breastmilk is unknown. An alternate drug is preferred over continuous high-dose, aspirin therapy. After daily low-dose aspiring (75 to 325 mg daily), no aspirin is excreted into breastmilk and salicylate levels are low. Daily low-dose aspirin therapy may be considered as an antiplatelet drug for use in breastfeeding women.[1][2][3]. If it is used by a nursing mother, monitor the infant for bruising and bleeding.
Possible effects of Aspirin on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Aspirin
Acetaminophen, Ibuprofen.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Bell AD, Roussin A, Cartier R et al. The use of antiplatelet therapy in the outpatient setting: Canadian Cardiovascular Society guidelines executive summary. Can J Cardiol. 2011;27:208-21. PMID: 21459270
2. Bates SM, Greer IA, Middeldorp S et al. VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141 (2 Suppl):e691S-736S. PMID: 22315276
3. Datta P, Rewers-Felkins K, Kallem RR et al. Transfer of low dose aspirin into human milk. J Hum Lact. 2017;33:296-9. PMID: 28418802
4. Levy G. Salicylate pharmacokinetics in the human neonate. In: Morselli PL, Garattini S, Sereni F, eds. Basic and therapeutic aspects of perinatal pharmacology. New York: Raven Press, 1975:319-30.
5. Erickson SH, Oppenheim GL. Aspirin in breast milk. J Fam Pract. 1979;8:189-90. PMID: 759544
6. Jamali F, Keshavarz E. Salicylate excretion in breast milk. Int J Pharm. 1981;8:285-90.
7. Putter J, Satravaha P, Stockhausen H. Quantitative analysis of the main metabolites of acetylsalicylic acid. Comparative analysis in the blood and milk of lactating women. Z Geburtshilfe Perinatol. 1974;178:135-8. PMID: 4422623
8. Findlay JW, DeAngelis RL, Kearney MF et al. Analgesic drugs in breast milk and plasma. Clin Pharmacol Ther. 1981;29:625-33. PMID: 7214793
9. Bailey DN, Welbert RT, Naylor A. A study of salicylate and caffeine excretion in the breast milk of two nursing mothers. J Anal Toxicol. 1982;6:64-8. PMID: 7098450
10. Unsworth J, d’Assis-Fonseca A, Beswick DT. Serum salicylate levels in a breast fed infant. Ann Rheum Dis. 1987;46:638-9. PMID: 3662653
11. Clark JH, Wilson WG. A 16-day-old breast-fed infant with metabolic acidosis caused by salicylate. Clin Pediatr. 1981;20:53-4. PMID: 7214793
12. Terragna A, Spirito L. [Thrombocytopenic purpura in an infant after administration of acetylsalicylic acid to the wet-nurse]. Minerva Pediatr. 1967;19:613-6. PMID: 6069440
13. Harley JD, Robin H. Late neonatal jaundice in infants with glucose-6-phosphate dehydrogenase-deficient erythrocytes. Aust Ann Med. 1962;11:148-55. PMID: 13960788
14. Ito S, Blajchman A, Stephenson M, Eliopoulos C et al. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol. 1993;168:1393-9. PMID: 8498418
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
