FRCPath Haem Part 1 MCQs-Transfusion 489

A 32-year-old G2P1 RhD-negative woman with no detectable immune anti-D antibodies is scheduled for an elective Caesarean section at 38+5 weeks for placenta accreta spectrum. She has previously received routine antenatal anti-D prophylaxis.

Her pre-operative antibody screen is negative and the fetus is believed to be RhD positive. Because major haemorrhage is anticipated, intraoperative cell salvage (IOCS) is established.

During surgery, she loses approximately 3.5 L of blood. Approximately 1.8 L of salvaged red cells are processed and subsequently reinfused. The baby is born well and cord blood confirms the baby is RhD positive.

The obstetric team asks the transfusion laboratory whether anti-D is required.

Which of the following is the MOST appropriate management?

A. No further anti-D is required because antenatal anti-D prophylaxis provides adequate protection during delivery

B. Administer 500 IU anti-D immediately

C. Administer a minimum of 1500 IU anti-D

D. Perform a Kleihauer test first and administer anti-D only if fetal red cells exceed 4 mL

E. Administer 1500 IU anti-D before reinfusion of the salvaged cells and repeat the same dose 24 hours later