Interferon Beta use while Breastfeeding
Interferon Beta Levels and Effects while Breastfeeding
Summary of Use during Lactation
The levels of interferon beta-1a in breastmilk are minuscule. In addition, because interferon is poorly absorbed orally, it is not likely to reach the bloodstream of the infant. A small number of nursing mothers receiving interferon beta-1a while partially breastfeeding their infants and one woman exclusively breastfed her infant while taking interferon beta-1b and reported no adverse effects. No special precautions appear to be required during breastfeeding while using interferon beta. Holder pasteurization (62.5 degrees C for 30 minutes) decreases the concentration of endogenous interferon-gamma by an average about 10%. 
Maternal Levels. Six women were receiving interferon beta-1a (Avonex, Biogen) 30 mcg intramuscularly once weekly for multiple sclerosis. Milk samples from both breasts were collected after pumping with an electric breast pump at 8 times after a dose at baseline and at 7 other times during the first 72 hours after a dose. Samples were combined and analyzed for interferon beta-1a. About half of the samples had undetectable (<20 ng/L) amounts of drug. The highest concentrations were found at 1 or 4 hours after the dose in all women. The highest concentration found was 171 ng/L in one woman. Using this value, the authors estimated that the maximum weight-adjusted dosage that an infant would receive is 0.006% of the maternal dose.
Infant Levels. Relevant published information was not found as of the revision date.
Effects in Breastfed Infants
Six women had been receiving interferon beta-1a (Avonex, Biogen) 30 mcg intramuscularly once weekly for multiple sclerosis for months to years. None of the mothers noticed any adverse effects in their breastfed infants.
A woman received interferon beta-1b (Betaferon, BayerHealthCare; dosage unspecified) for multiple sclerosis throughout pregnancy. She continued the drug while she exclusively breastfed her infant. At 5 months of age, the infant was monitored regularly by a physician and was developing well with no abnormalities.
Possible Effects on Lactation
Relevant published information was not found as of the revision date.
Alternate Drugs to Consider
1. Ewaschuk JB, Unger S, O'Connor DL et al. Effect of pasteurization on selected immune components of donated human breast milk. J Perinatol. 2011;31:593-8. PMID: 21330996
2. Hale TW, Siddiqui AA, Baker TE. Transfer of interferon beta-1a into human breastmilk. Breastfeed Med. 2012;7:123-5. PMID: 21988602
3. Rockhoff M, Hellwig K. [Family planning and interferon (beta)-1b - A case report of successful hormonal stimulation, pregnancy and breast-feeding under interferon (beta)-1b]. Aktuel Neurol Suppl. 2012;39 Suppl 1:S49-S51.
Interferon Beta Identification
CAS Registry Number
- Immunologic Adjuvants
LactMed Record Number
Information from the National Library of Medicine's LactMed Database.
Last Revision Date
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.