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Perioperative contraception during urgent lower-limb surgery and prolonged immobilisation — DFSRH MCQ

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HardImmobilityPerioperative contraception during urgent lower-limb surgery and prolonged immobilisationDFSRH

A 29-year-old woman sustains a displaced trimalleolar ankle fracture and is scheduled for urgent open reduction and internal fixation tomorrow. Postoperatively, she is expected to remain non-weight-bearing in a below-knee cast for 6 weeks. She uses a combined oral contraceptive containing 30 micrograms ethinylestradiol and levonorgestrel in a 21/7 regimen. She is on day 18 of the current packet, has taken all tablets correctly and had condomless intercourse 48 hours ago. She has had no vomiting or interacting medication. She has no personal or family history of venous thromboembolism, her BMI is 24 kg/m² and she does not smoke. Pregnancy testing is negative. There is no contraindication to pharmacological thromboprophylaxis. She wishes to continue using an oral contraceptive and asks whether stopping her pill now would create a pregnancy risk. Which is the most appropriate management plan?

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

Reveal the answer and explanation

Correct answer: D — Stop the combined pill now, start a desogestrel progestogen-only pill immediately without emergency contraception, and arrange protocol-based thromboprophylaxis

Urgent lower-limb surgery followed by 6 weeks of non-weight-bearing combines major surgery with prolonged immobilisation. Continued combined hormonal contraception therefore represents an unacceptable thrombotic risk. The pill should be stopped immediately. Because it could not be discontinued at least 4 weeks preoperatively, the surgical team should undertake VTE and bleeding risk assessment and provide appropriate mechanical and/or pharmacological thromboprophylaxis. She is in week 3 of correctly used combined contraception. Condomless intercourse 48 hours earlier was contraceptively protected, and direct switching to a desogestrel progestogen-only pill requires neither emergency contraception nor additional precautions. Combined contraception should not be restarted during continuing lower-limb immobilisation; guidance advises waiting until at least 2 weeks after full mobilisation. A retains an avoidable oestrogen-related risk despite prophylaxis. C incorrectly treats protected intercourse as an emergency-contraception indication. D creates an unnecessary contraceptive gap: a hormone-free interval is not required when switching during week 3 after correct pill use. E restarts oestrogen while the principal provoking factor—non-weight-bearing immobilisation—remains present and also omits explicit perioperative prophylaxis planning.

Reference: FSRH Guideline: Combined Hormonal Contraception (October 2023) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-guideline-combined-hormonal-contraception-october-2023.pdf FSRH Clinical Guideline: Progestogen-only Pills (August 2022, amended July 2023) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-ceu-clinical-guideline-progestogen-only-pills-aug22-amended-11july-2023-.pdf NICE NG89: Venous thromboembolism in over 16s—reducing the risk of hospital-acquired DVT or pulmonary embolism (2018) — https://www.nice.org.uk/guidance/ng89/chapter/Recommendations