Hemolytic disease of the fetus and newborn (HDFN) is an alloimmune disorder between the mother and fetus, one with significant risk for dire health consequences for both. Fortunately, a better understanding of the neonatal Fc receptor (FcRn) pathway along with the emergence of an inhibitor of this pathway has brought with it an opportunity to greatly reduce the potential harm associated with HDFN. Join us as Drs. Kenneth Moise and Kara Markham discuss the pathophysiology of HDFN and present key clinical data that may change the landscape of medical intervention for HDFN.