The remaining issue in this case is to determine if one vial of RhIG is sufficient or if there has been a FMH >30 mL of whole blood, requiring more than one vial of RhIg (300 µg).
Recall that the incidence of FMH greater than 30 mL at delivery is rare and estimated to be about 1 in 400 deliveries (~0.3%).
The laboratory used the rosette test to screen for FMH and it was negative. Accordingly, quantitation using the KB test or flow cytometry was not needed.
Based on the negative rosette test, the mother was injected with one vial of RhIg (300 µg). She was later discharged along with her healthy infant.