Which patient groups must receive RhD negative red blood cells?

The selection of RhD negative red blood cells for transfusion is particularly critical for females of child-bearing potential with an unknown blood group. This is due to the risk of Rh incompatibility, which can occur if an RhD negative female receives RhD positive red blood cells and later becomes pregnant. If the mother is RhD negative and the fetus is RhD positive, this can lead to hemolytic disease of the newborn, where the mother's immune system attacks the RhD positive cells of the fetus. Using RhD negative blood in these situations minimizes the risk of developing antibodies that could affect future pregnancies.

In contrast, the other options do not capture the specific clinical considerations surrounding RhD status and the potential consequences of mismatched blood transfusions. While individuals above a certain age or sex alone do not dictate the necessity of RhD negative blood, the critical nature of RhD compatibility underscores the need for careful selection in potentially child-bearing females, particularly when their blood type is not already known.