No information is available on the use of ravulizumab during breastfeeding. Because ravulizumab is a large protein molecule with a molecular weight of about 148,000 Da, absorption is unlikely because it is probably destroyed in the infant's gastrointestinal tract. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[1] The manufacturer recommends that breastfeeding be discontinued during ravulizumab therapy and for 8 months after the final dose.