No information is available on the clinical use of cipaglucosidase alfa during breastfeeding. Because cipaglucosidase alfa is a large protein molecule with a molecular weight of about 110,000 Da, the amount in milk is likely to be very low.[1] It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[2] However, the drug is given with miglustat, which has no safety information during breastfeeding, so the manufacturer recommends that neither drug be given to nursing mothers. An alternate drug may be preferred.