Navigating monoclonal antibody use in breastfeeding women Do no harm or do little good?

Many neurologic diseases disproportionately affect women, particularly during their reproductive years. For many of these diseases, monoclonal antibodies (mAbs) are becoming widely available as a treatment option, for example, in migraine, multiple sclerosis, and myasthenia gravis. Yet, despite how common pregnancy is (latest estimates suggest that 86% of US women ages 40-44 have given birth), there is a paucity of research on the safety of prescription medications, including mAbs, during the peripartum period. In this article, we focus on the safety of mAbs during breastfeeding. We summarize how pregnancy affects the trajectory of these diseases and explore the benefit derived from mAb therapies. We posit that as neurologists, we are uniquely poised to lead the study of peripartum safety for the mAbs now on the market and provide a framework for their future study. Some of the most common neurologic diseases are more common in women, especially during their reproductive years.(1-4) Women take an average of 3 medications during pregnancy and 4 medications during breastfeeding.(5,6) However, the safety of these medications during pregnancy and breastfeeding is understudied.(5,6) Effectively, peripartum women are drug orphans, and the ethical implications of this status quo have recently come to the fore.(7-9)