Hemolytic Disease of the Newborn Infant Caused by Maternal Sensitization to the Blood Factor hr' (c) : Report of Two Cases with Special Reference to the Etiologic Significance of Multiple Blood Transfusions in Rh Positive Women Prior to Gestation

1. Intragroup Rh incompatibility between an Rh-positive mother and an Rh-positive infant presents an unusual pattern of maternal isosensitization.

2. The antibody found in the sera of two Rh-positive mothers appeared to be of anti-hr' (anti-c) specificity.

3. Evidence of hemolytic disease in both infants was found and the findings directly correlated with this maternal antibody.

4. The welfare of the infant greatly depends on prompt recognition of this unusual pattern of maternal isosensitization and proper treatment of its disease.

5. An attempt has been made to evaluate the role of multiple transfusions of Rh-negative blood which had been given to an Rh-positive mother four years prior to gestation.

6. The wide spacing of several transfusions or transfusion and pregnancy respectively appears to be probably the most important factor in the development of isosensitization.

7. The possible danger in using Rh-negative blood as a universal safe donor is briefly discussed.