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Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006-.

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Drugs and Lactation Database (LactMed®) [Internet].

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Last Revision: November 16, 2020.

Estimated reading time: 1 minute

CASRN: 679809-58-6

image 135331472 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

Limited information indicates that maternal enoxaparin in doses up to 40 mg daily do not to cause any adverse effects in breastfed infants. Because its large molecular weight of 2000 to 8000 daltons, enoxaparin would not be expected to be excreted into breastmilk or to be absorbed from breastmilk by the infant. No special precautions are required.[1]

Drug Levels

Maternal Levels. Relevant published information was not found as of the revision date.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Ten women received enoxaparin 20 mg and 2 received 40 mg daily by subcutaneous injection from the prepartum to the postpartum period. At 5 to 7 days postpartum, anti-Xa activity (a measurement of enoxaparin anticoagulant activity) was undetectable in their 12 completely breastfed term neonates 1.5 to 3 hours after they were breastfed for at least 5 days. No bleeding was detected among the infants during maternal enoxaparin therapy.[2]

A pregnant woman suffered blood clots in the sinuses and 2 small intracranial hemorrhages at 8 weeks of gestation, followed by status epilepticus. She was treated with enoxaparin 40 mg twice daily throughout pregnancy and for 3 months postpartum as well as levetiracetam and lacosamide. Her infant was about 50% breastfed for the first 15 days of life. The infant showed normal development at 7 months of age.[3]

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.


Bates SM, Rajasekhar A, Middeldorp S, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: Venous thromboembolism in the context of pregnancy. Blood Adv. 2018;2:3317–59. [PMC free article: PMC6258928] [PubMed: 30482767]
Guillonneau M, de Crepy A, Aufrant C, et al. Arch Pediatr (Paris). 1996;3:513–4. [Breast-feeding is possible in case of maternal treatment with enoxaparin] [PubMed: 8763733]
Ylikotila P, Ketola RA, Timonen S, et al. Early pregnancy cerebral venous thrombosis and status epilepticus treated with levetiracetam and lacosamide throughout pregnancy. Reprod Toxicol. 2015;57:204–6. [PubMed: 26187779]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding



Low Molecular Weight Heparin

Disclaimer: Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.

Copyright Notice

Attribution Statement: LactMed is a registered trademark of the U.S. Department of Health and Human Services.

Bookshelf ID: NBK500600PMID: 29999660


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