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RhD-negative tubal ectopic pregnancy at 12+1 weeks undergoing surgical management — DFSRH MCQ

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EasyEctopic PregnancyRhD-negative tubal ectopic pregnancy at 12+1 weeks undergoing surgical managementDFSRH

A 29-year-old woman is diagnosed with an unruptured right tubal ectopic pregnancy containing a fetal pole with cardiac activity. She is haemodynamically stable and laparoscopic surgery is planned. She is RhD-negative with a negative antibody screen. Gestation calculated from her last menstrual period is 11+5 weeks, whereas crown–rump length on transvaginal ultrasound corresponds to 12+1 weeks. Which is the most appropriate approach to anti-D immunoglobulin prophylaxis?

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

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Correct answer: D — Offer at least 250 IU anti-D because the ultrasound estimate is 12+1 weeks

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

NICE recommends using the ultrasound estimate when ultrasound dating and the last menstrual period give discrepant gestations. This patient should therefore be managed as being at 12+1 weeks, rather than 11+5 weeks. For an RhD-negative, non-sensitised person at 12+0 to 12+6 weeks undergoing medical or surgical management of an ectopic pregnancy, at least 250 IU (50 micrograms) of anti-D immunoglobulin should be offered. A is incorrect because the current UK threshold changes at 12+0 weeks, despite both estimates falling within the conventional first trimester. B incorrectly prioritises menstrual dating over ultrasound. It would apply if the ultrasound-derived gestation were also no more than 11+6 weeks, when anti-D is not recommended even for surgical management. D is incorrect because the indication does not depend on laparoscopic versus open access. E is incorrect because NICE advises against using a Kleihauer test to quantify fetomaternal haemorrhage in this setting. These recommendations were introduced in the June 2026 NICE update and replace the previous distinction based principally on whether surgical management was performed.

Reference: Ectopic pregnancy and miscarriage: diagnosis and initial management — Anti-D immunoglobulin prophylaxis (Updated 17 June 2026) — https://www.nice.org.uk/guidance/ng126/chapter/anti-d-immunoglobulin-prophylaxis