RhD alloimmunization is an immunological condition caused by the presence of maternal anti-RhD antibodies that destroy fetal and newborn red blood cells, causing Hemolytic Disease of the Fetus and Newborn (HDFN).(1) Anemia and increased serum bilirubin, due to the exacerbated hemolytic process, are responsible for the associated morbidities observed in the newborn.(2) Although the fetal hyperbilirubinemia is largely resolved by placental metabolism, in severe cases the anemia and its repercussions can be fatal. The gene discussed is RHD; the disease is alloimmunization.