Background: Small-volume fetomaternal hemorrhage is frequently observed after intrauterine transfusion. The Kleihauer-Betke test, the reference method for identifying fetomaternal hemorrhage, cannot be used after intrauterine transfusion, because the adult red blood cells used for transfusion cannot be distinguished from maternal red blood cells.
Case: Massive fetomaternal hemorrhage secondary to intrauterine transfusion led to fetal hemorrhagic stroke. We used a method based on blood group identification in the maternal blood to confirm and to quantify fetomaternal hemorrhage.
Conclusion: Fetal stroke may result from severe hypovolemia and low cerebral blood flow caused by fetomaternal hemorrhage, rather than from fetal anemia itself.