FRCPath Haem Part 1 MCQs-Transfusion 474
A 32-year-old woman, gravida 2 para 1, at 39 weeks' gestation undergoes an emergency Caesarean section for suspected placental abruption. She is RhD-negative and has no detectable immune anti-D antibodies.
Significant intraoperative haemorrhage occurs, with an estimated blood loss of 2.5 L. Intraoperative cell salvage is used, and 800 mL of salvaged red cells are reinfused.
The baby is born alive and is subsequently confirmed to be RhD-positive.
The obstetric team contacts the transfusion laboratory regarding postpartum anti-D prophylaxis.
Which ONE of the following is the most appropriate management?
A. Give 500 IU anti-D immunoglobulin immediately; no further testing is required
B. Give 500 IU anti-D immunoglobulin and perform a Kleihauer test 30–45 minutes later
C. Give a minimum of 1500 IU anti-D immunoglobulin after reinfusion of the salvaged red cells, followed by maternal FMH testing 30–45 minutes later
D. Perform FMH testing first and administer anti-D only if fetal red cells are detected
E. Give 1500 IU anti-D immunoglobulin before reinfusion of the salvaged red cells and repeat the dose after delivery
Correct answer: C
Explanation:
In a previously non-sensitised RhD-negative woman undergoing Caesarean section where intraoperative cell salvage has been used, reinfused salvaged blood may contain a significant quantity of fetal red cells.
Therefore, if the baby is RhD-positive (or the baby's RhD group is unknown), a minimum of 1500 IU anti-D immunoglobulin should be given following reinfusion of the salvaged cells.
A maternal sample should then be obtained approximately 30–45 minutes after reinfusion for estimation of fetomaternal haemorrhage (FMH). If the FMH exceeds that covered by the initial anti-D dose, additional anti-D is required.
Exam pearl 🧠
ICS + RhD-negative + non-sensitised + RhD-positive/unknown baby → 1500 IU anti-D + FMH testing 30–45 min after reinfusion.
The reason for the…