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Sexual exposure to chronic hepatitis B during pregnancy — DFSRH MCQ

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HardImmunizationsSexual exposure to chronic hepatitis B during pregnancyDFSRH

A 30-year-old woman at 10 weeks’ gestation attends an integrated sexual health service. Her regular male partner has newly confirmed chronic hepatitis B infection. They first had condomless vaginal intercourse 4 months ago and most recently had intercourse 4 days ago. They intend to continue their relationship. She has never received hepatitis B vaccine. Baseline HBsAg, anti-HBc and anti-HBs samples have been taken, but the results will not be available until tomorrow. She has no vaccine allergy or immunocompromising condition. Which is the most appropriate management plan?

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Correct answer: A — Give vaccine at 0, 1, 2 and 12 months without HBIG; advise condoms until after dose three and offer HBsAg testing at 6 months

This is ongoing sexual exposure to a partner with chronic hepatitis B. Vaccination should begin immediately and should not be delayed for baseline serology. Pregnancy is not a reason to withhold hepatitis B vaccine because it is inactivated and protection is required during pregnancy. An accelerated post-exposure schedule at 0, 1 and 2 months is appropriate. A further dose at 12 months is indicated because future exposure is likely. HBIG is not indicated: for a newly diagnosed chronic source, it is considered when the first unprotected sexual contact with the new partner occurred within the preceding week, not merely when the latest contact occurred. Here, exposure began 4 months ago. Condoms are advised until after the third vaccine dose, and HBsAg testing can be offered 6 months after vaccination was initiated to exclude acquired infection. A delays indicated prophylaxis. B incorrectly applies the HBIG window to the most recent rather than the first exposure to a chronic source; it would be appropriate after recent exposure to acute hepatitis B, or when first contact with a chronic source was within a week. C uses the slower pre-exposure schedule despite a need for rapid protection. D omits the 12-month dose despite continuing risk. E therefore provides the appropriate sequence.

Reference: Immunisation against infectious disease: hepatitis B — Green Book chapter 18 (5 February 2026) — https://assets.publishing.service.gov.uk/media/699c8d35e1c6bad1576fbc01/Green-book-on-immunisation-hepatitis-B-chapter_-_05022026.pdf