skip to main content

ABO HDN — RACP Paediatrics MCQ

Instant feedback + full explanation. One question, done properly.

HardHaematology & OncologyABO HDNRACP Paediatrics

A fetus has severe anaemia and hydrops. The mother is RhD positive but has high-titre anti-K antibodies after a previous transfusion; the fetus is Kell-positive. Which mechanism and response are most accurate?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Refer for fetal surveillance and possible intrauterine transfusion for anti-K HDFN

Explanation lettering: C = shown as B · D = shown as C · E = shown as D · B = shown as E

E is correct because anti-K is a clinically important maternal IgG antibody that can cause severe fetal anaemia and requires specialist maternal-fetal monitoring and possible intrauterine transfusion. A wrongly equates RhD positivity with absence of other alloantibodies. B ABO disease is generally mild to moderate and does not fit the defined antigen-antibody pair. C delays treatment of antenatal disease. D RhD immunoglobulin prevents anti-C sensitisation; it neither treats anti-K nor reverses established anaemia.

Reference: Royal Children’s Hospital Melbourne, Jaundice in early infancy: https://www.rch.org.au/clinicalguide/guideline_index/Jaundice_in_Early_Infancy/; Australian Red Cross Lifeblood, Haemolytic disease of the fetus and newborn: https://www.lifeblood.com.au/health-professionals/clinical-practice/clinical-indications/HDFN