Hereditary Anemias as a Monogenic Etiology for Nonimmune Hydrops Fetalis

Overall, ES confirmed the etiology of hereditary anemia in 2.4% (5/207) of genetically diagnosed NIHF cases. Hereditary anemias, therefore, represent a distinct and clinically relevant subset of ES-diagnosed NIHF cases. ES should be considered first line in fetuses with NIHF, as common non-genetic causes such as fetomaternal hemorrhage, infectious etiologies, and alloimmunization are excluded. It is also indicated when fetal anemia is suspected, particularly in the setting of elevated MCA Dopplers with a negative evaluation for common hemoglobinopathies and nongenetic etiologies.