Anti-M as a Fetal Hemolytic Antibody

Clinical Significance and Pathophysiology

• The Society for Maternal-Fetal Medicine guidelines identify anti-Kell, anti-Duffy (Fya), and anti-Kidd (Jka, Jkb) as atypical antibodies "known to cause severe fetal anemia," but Anti-M is notably absent from this high-risk list, as stated in guidelines from the Society for Maternal-Fetal Medicine 1

Management Approach

Surveillance Strategy

• For IgG Anti-M reactive at 37°C or history of affected pregnancy, serial middle cerebral artery peak systolic velocity (MCA-PSV) Doppler monitoring to detect fetal anemia is recommended, following the same protocols used for other alloimmune antibodies, as suggested by the American College of Obstetricians and Gynecologists 1