skip to main content

Rh D Alloimmunization Prevention — DRCOG MCQ

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

HardPrevention of Rh D AlloimmunizationRh D Alloimmunization PreventionDRCOG

A non-sensitised RhD-negative woman at 24+3 weeks presents after a painless vaginal bleed. The fetus is viable and she received no anti-D for this episode; routine prophylaxis is booked for 28 weeks. What anti-D plan is required?

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

Reveal the answer and explanation

Correct answer: E — Give event-related anti-D now, assess fetomaternal haemorrhage and retain routine antenatal prophylaxis

E is correct. Bleeding after 20 weeks is a potentially sensitising event: UK practice gives at least 500 IU anti-D as soon as possible and within 72 hours, assesses fetomaternal haemorrhage for any additional dose, and still provides routine antenatal prophylaxis. A confuses routine prophylaxis with event-related cover. B uses the early-pregnancy dose and incorrectly cancels routine prophylaxis. C delays the minimum dose while awaiting quantification; testing determines additional cover. D makes prevention depend on partner testing and recurrence rather than the current event. A prior or future routine dose does not erase a new sensitising-event indication.

Reference: RCOG Green-top Guideline No. 63: Antepartum haemorrhage: https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/antepartum-haemorrhage-green-top-guideline-no-63/ NHS: Rhesus disease—prevention: https://www.nhs.uk/conditions/rhesus-disease/prevention/ NICE TA156: Routine antenatal anti-D prophylaxis—recommendations: https://www.nice.org.uk/guidance/ta156/chapter/1-Recommendations