The remaining issue in this case is to determine if one vial of RhIG is sufficient or if there has been an 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.
RhIG Dosage:
Based on the negative rosette test, the mother was injected with one vial of RhIG (300 µg). The mother was later discharged along with the healthy infant.