Studies on Rh Prophylaxis

The incidence of Rh immunization of Rh‐negative volunteers given approximately 500 ml of Rh‐positive blood is 18 out of 22. Complete Rh immune suppression was achieved in a treated group given a precalculated dose of Rh immune globulin. Rh immune prophylaxis is safe, effective and practical after transfusion accidents or massive fetomaternal hemorrhages where large volumes of Rh‐positive blood enter the circulation of Rh‐negative individuals. The dose of RhoGAM,* Rho(D) Immune Globulin (Human) found to be effective in suppressing an immune response to the Rh factor was 20 μg/ml of red blood cells (not whole blood). Since each vial contains no less than 300 μg of anti‐Rho(D), the potency for RhoGAM is 15 ml of red blood cells/vial.