Is Glatiramer safe while breastfeeding?

Summary of use during breastfeeding

Glatiramer is the active portion of the drug, glatiramer acetate. Breastfeeding is not expected to result in clinically relevant exposure of the infant to the drug. Follow-up of infants indicates that maternal use of glatiramer acetate does not appear to cause any adverse effects in breastfed infants. Glatiramer acetate is generally considered safe by most experts and is one of the preferred disease-modifying agents for treating multiple sclerosis during breastfeeding.[1-6] No special precautions appear to be required during breastfeeding while using glatiramer and breastfeeding can resume immediately after injection.[7]

Effects on the breastfed infant

Nine mothers received glatiramer acetate (dosage not stated) during pregnancy and postpartum for multiple sclerosis and breastfed their infants for an average of 3.6 months (range 1 to 12 months). No infections, signs of inadequate digestion or other important ill effects were reported in their breastfed infants during the neonatal period. Follow-up of the infants at 1 year or longer found no neurological or developmental deficits in the infants except for one otherwise normal infant with delayed language development who had been breastfed for 3 months.[9]

Three mothers received glatiramer acetate (dosage not stated) for multiple sclerosis during pregnancy and postpartum. All of their infants were exclusively breastfed for 6 months and no noticeable problems were reported in any of them.[10]

In data collected from 4 countries, 41 women received glatiramer acetate, and 17 women received interferon during pregnancy and postpartum for treatment of multiple sclerosis. Of these, 63% breastfed (extent not stated) their infants for a mean of 8.8 months. No mention was made of adverse reactions in breastfed infants.[11]

Among 1182 live birth pregnancies in the manufacturer’s pharmacovigilance database, breastfeeding was reported for 14.3% of women (n = 169). During the first month after birth breastfeeding was reported in 10 mothers using 20 mg/mL daily and 64 using the 40 mg/mL three times weekly dosage regimen. Follow-up questionnaires were sent to patients or their healthcare providers at 1 and 12 months postpartum. Among 40 women who completed the 12-month questionnaires, 3 received the 20 mg/mL dose, 36 received the 40 mg/mL dose, and 1 received both doses. Of 27 women with known breastfeeding practices, exclusive breastfeeding for 4 or more months was reported for 17 (63.0%) respondents. Partial breastfeeding, defined as breastfeeding for less than 4 months or mixed breast and bottle feeding, was reported for ten (37.0%) mothers. The mean duration of exposure while breastfeeding was 7 months (SD = 4.3 months) with durations up to 13 months. Of 40 breastfeeding women, infant characteristics at birth and at approximately 12 months of age were available for 18 breastfed infants, all with the 40 mg/mL dose. The mean infant weight and length at birth and 12 months were within the normal range for the World Health Organization z-score and percentiles.[12] A follow-up study was conducted at 4 years. Of the 384 women who completed a questionnaire at 12 months postpartum, 146 reported infant glatiramer exposure during breastfeeding. Sixty-two women reported exclusive breastfeeding for 4 or more months, 21 reported partial breastfeeding, and 43 had ongoing breastfeeding of unknown duration. The average duration of glatiramer exposure during breastfeeding was 8 months (SD = 5.2) with maximum duration up to 30 months. Some infants had respiratory infections, with 12 of 125 requiring hospitalization. Length and weight information for 55 infants at 12 months were within the normal range of WHO z-score and percentiles.[13] A further follow-up with data from June 1, 2018, to March 31, 2025 identified 281 infants who were breastfed by mothers taking glatiramer. Among 175 breastfed infants with available hospitalization data, 15 (8.6%) experienced hospitalization for various reasons. Overall, 66 infants with known growth measurements showed normal weight-to-length ratios and age-appropriate growth.[14]

In a retrospective, non-interventional, study from the German Multiple Sclerosis & Pregnancy Registry, 60 infants breastfed by mothers with multiple sclerosis treated with glatiramer were compared to 60 breastfed infants of mothers with MS not treated with a disease-modifying therapy. The median duration of breastfeeding during glatiramer use was 7 months (range 0.2 to 19.1 months). No difference was found in the number of hospitalizations for infection between the two groups up to 18 months of age. No differences in weight, length, or head circumference were seen between infants in the two cohorts up to 12 months of age.[15] A follow-up analysis found no difference in the number or types of serious adverse effects in infants between the two groups.[3]

A mother taking glatiramer reported that her newborn infant who was 50% breastfed experienced hypoglycemia. The reaction was rated as possible, but mild.[16]

Effects on milk supply

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

Levels in milk

Maternal Levels. In a manufacturer-sponsored study, healthy volunteers were given 60 mg of glatiramer acetate subcutaneously. Blood samples were obtained at 5, 15, 30, 60, 120, 240, and 360 minutes after injection. Glatiramer was undetectable (<50 mcg/L) in the serum of 8 of 17 subjects; it was detectable for up to 30 minutes in 8 subjects and up to 360 minutes in one other. Assuming that milk levels equal peak serum levels, the authors estimated that in the worst-case scenario, an exclusively breastfed infant would receive a relative infant dose of 9% of the maternal weight-adjusted dosage in milk. However, the infant would be systemically exposed to a maximum of only 0.2% of the mother’s dose when the poor oral bioavailability is considered.[8]

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

Alternatives LactMed lists

• Immune Globulin
• Interferon Beta
• Methylprednisolone