Approach to managing maternal alloantibodies other than RhD

HDFN: hemolytic disease of the fetus and newborn; RBC: red blood cell; MCA-PSV: middle cerebral artery peak systolic velocity.

* Cell-free DNA testing is performed on a maternal blood sample. In many countries including the United States, cell-free DNA testing for red blood cell antigens other than RhD is not routinely available. In countries where cell-free testing is available, it is usually only done for Kell, Rhc, RhC, and RhE. If cell-free DNA testing is not available, serial maternal antibody titers are obtained and amniocentesis is performed to determine fetal antigen status from amniocytes if/when the critical titer is reached.