By Elizabeth Salas, MPH, Teratology Information Specialist, MotherToBaby California

Welcoming a new baby brings a lot of excitement as well as questions, and every mom wants her new bundle of joy to get the best start possible. One of the best things a mom can do to give her newborn a healthy start is to breastfeed – but if you have a medical condition that requires taking medication, should that impact your decision about whether to breastfeed? Let’s review what we know about the medications used to treat multiple sclerosis (MS) and what we know about their use in breastfeeding.

WHICH MEDICATIONS ARE SAFE TO USE WHILE BREASTFEEDING?

Corticosteroids are closely related to a naturally occurring hormone in the body called cortisol. These medications can be effective in treating relapses but do not change the long-term progress of MS. Prednisolone, methylprednisolone, triamcinolone, and dexamethasone are all corticosteroids that have been approved for the treatment of MS. Most corticosteroids are transferred into breast milk in small amounts.

Dexamethasone and triamcinolone are not as well studied during lactation, so other corticosteroids may be preferred especially when breastfeeding newborns or pre-term infants.

Prednisolone is an activated form of prednisone and doses are approximately equivalent for one compared to the other. Studies suggest prednisone doses up to 50mg a day are not likely to be a problem for breastfed infants. When using higher doses, postponing breastfeeding for 4 hours after administering the dose can reduce the amount of medication transferred into the breast milk, but is probably not necessary with usual oral doses. Methylprednisolone doses up to 8mg a day produce low levels in breast milk and are unlikely to cause negative effects in breastfed babies. When treating MS relapse or for monthly therapy with intravenous doses, various sources recommend avoiding breastfeeding during an infusion and for 4-8 hours afterwards. Overall, while corticosteroids have not been shown to cause negative effects on breastfed infants, occasionally these medications may cause a temporary loss of milk supply.

Disease Modifying Treatments are commonly used to treat and halt the progression of MS. Some information exists regarding the use of these medications in lactation, including the concentration of these medications in breast milk as well as individual and group reports of babies that have been breastfed.

Interferons are naturally occurring proteins that are made by cells of the immune system in response to bacteria, viruses, and other foreign substances that invade the body. Medications that contain interferons include Betaseron® and Extavia®(interferon beta-1b), Avonex® and Rebif® (interferon beta-1a), and Plegridy®(peginterferon beta-1a). Interferon medications are made up of large proteins. The size of these proteins is expected to limit the transfer of the medication into breast milk. Based on studies measuring the levels of interferon beta-1a in breast milk, the relative dose received by the infant is estimated to be 0.006% of the maternal dose. This expected dose is very low and to date no adverse effects have been reported in breastfed infants. While levels of interferon beta-1b in breast milk have not been measured, some experts suggest the relative infant dose would likely be similar to the estimated dose received with interferon beta-1a treatment.

Copaxone® (glatiramer) has not been measured in breast milk. The intact drug would not be expected to transfer into breast milk because it is usually not detectable in the bloodstream. Once the drug starts to break down, it’s possible that some of the breakdown products reach the bloodstream. However, if medication were to pass into the breast milk, it is likely to be broken down in the infant gut. Of the disease-modifying agents used to treat MS, this appears to be the preferred treatment during breastfeeding.

There is limited published information about the use of Tysabri®(natalizumab) during breastfeeding. One case suggests that after initiating treatment, increasing amounts of the medication may transfer into breast milk over several weeks. Due to the large size of the protein molecule, it would probably be broken down in the gastrointestinal tract and is unlikely to be absorbed by the infant gut. Some experts recommend breastfeeding be avoided during treatment with Tysabri®, while others suggest that it should be used with caution until more information becomes available. Precaution should always be taken with newborns or pre-term infants, whose gastrointestinal tract is still maturing and who may be more likely to absorb a medication.

Tecfidera®(dimethyl fumarate), Gilenya®(fingolimod), and Aubagio®(teriflunomide) have not been studied during lactation and the amount of medication that passes into the breast milk is unknown. Due to a lack of information, alternate medications may be preferred for moms wishing to breastfeed. Novantrone®(mitoxantrone) is an antineoplastic treatment (cancer therapy) and little is known about safety during breastfeeding. When levels of the medication were measured in one patient’s breast milk, detectable levels were found 28 days after the last dose. Generally, most sources consider treatment with antineoplastic medications not compatible with breastfeeding.

WHY BREASTFEED?

There are many reasons to breastfeed including benefits for both baby and mom. Breast milk provides babies with the nutrients they need. As a baby gets older, the breast milk even changes to meet those changing needs. Babies also receive immunoglobulins from mom through breast milk, especially in the first few days after delivery. These special proteins help protect babies from getting infections. Breastfeeding also allows mom and baby to have close physical contact. This can be comforting for baby and may boost the levels of a hormone called oxytocin in mom. The release of oxytocin can help with the letdown of breast milk and can have a calming effect on mom. Breast fed infants are also less likely to experience vomiting and diarrhea as well as a serious gastrointestinal disease in pre-term infants called necrotizing enterocolitis. Studies have also found that the benefits of breastfeeding may extend into childhood, with lower rates of asthma, childhood obesity, ear infections, lower respiratory infections, eczema, childhood leukemia, type 2 diabetes, and Sudden Infant Death Syndrome (SIDS) seen in children who were breastfed.

To learn about the benefits of breastfeeding and for additional information visit http://www.womenshealth.gov/breastfeeding/

Some studies have found that breastfeeding may have a protective effect against postpartum MS relapses; however, disease activity may influence a patient’s decision to breastfeed or resume treatment. A recent review suggested that disease activity that is subclinical (i.e., not severe enough to have definite or observable symptoms) can be monitored in breastfeeding women using MRI with contrast. Also, monthly intravenous corticosteroids and immunoglobulin have been used to prevent or reduce the chances of postpartum relapse; however, to date no official organization has established recommendations while a woman is breastfeeding. Women with MS who choose to breastfeed should speak with their doctors about how to avoid potential triggers to minimize the chance of relapse or to keep symptoms from becoming worse.

It may not be possible for all moms with MS to treat their condition and breastfeed. It is important to remember that mom staying healthy or getting healthy doesn’t just benefit mom – a baby benefits from a mom that is able to care for herself and her little one. Your baby’s age, health, and whether they were born pre-term may also influence the decision to breast feed while treating your MS. To determine what’s right for you and your baby, we encourage you to speak with your doctors and your baby’s pediatrician regarding your options.

WHERE CAN I GET MORE INFORMATION?

For more information about any of the medications discussed above or any other exposures during pregnancy or lactation, you can speak with a MotherToBaby counselor by calling us toll free at (866) 626-6847. Our service is FREE and confidential. If you’d like to know more about current MS pregnancy registries, please contact one of our MotherToBaby Pregnancy Studies experts toll free at (877) 311-8972.

Elizabeth Salas is the Lead Teratology Information Specialist for MotherToBaby California, a non-profit that provides information to healthcare providers and the general public about medications and more during pregnancy and breastfeeding. She is based at the University of California, San Diego, and is passionate about the work MotherToBaby is doing to promote healthy moms, healthy pregnancies and healthy babies.

Interested in more information about MS and pregnancy? Check out MotherToBaby’s blogs, “MS: The Diagnosis that Doesn’t Mean Missing Out on Motherhood!” and “For Women with MS: Making Decisions about Pregnancy, Breastfeeding, and More”

MotherToBaby is a service of the international Organization of Teratology Information Specialists (OTIS), a suggested resource by many agencies including the Centers for Disease Control and Prevention (CDC). If you have questions about medications, vaccines, diseases, or other exposures, call MotherToBaby toll-FREE at 866-626-6847 or call the Pregnancy Studies team directly at 877-311-8972. You can also visit MotherToBaby.org to browse a library of fact sheets, as well as visit our Multiple Sclerosis and Pregnancy page at MotherToBaby Pregnancy Studies, www.PregnancyStudies.org.

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