Enoxaparin and Breastfeeding

Summary of use during lactation

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 in milk and infant serum

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] Following a successful uterus transplant and embryo transfer, a newborn infant was breastfed by a mother taking tacrolimus, azathioprine 150 mg (2 mg/kg), prednisone 5 mg, and enoxaparin 40 mg daily. The tacrolimus dosage was adjusted to achieve a serum concentration of 5 to 7 mcg/L. The mother breastfed (exclusively?) for 8 weeks and weaned over the next 4 weeks. At 15 months, the infant was achieving all developmental milestones.[4]

Effects on lactation and breastmilk

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

Alternative drugs to consider

Acenocoumarol, Dalteparin, Enoxaparin, Heparin, Rivaroxaban, Warfarin

References

1. 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;2:3317–59.30482767 PubMed
2. Guillonneau M, de Crepy A, Aufrant C, et al. Breast-feeding is possible in case of maternal treatment with enoxaparin. Arch Pediatr (Paris) 1996;3:513–4.8763733 PubMed
3. 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;57:204–6.26187779 PubMed
4. Deans R, Gerstl B, Shand AW, et al. The first live term birth following uterus transplantation in Australia. Med J Aust 2025;223:404–9.40406819 PubMed