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Emergency Contraception — DFSRH MCQ

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EasyEmergency ContraceptionDFSRH

A 29-year-old woman requests emergency contraception 36 hours after a condom split on cycle day 11. She has regular 28–30-day cycles and reports no other unprotected sexual intercourse this cycle. Her BMI is 23 kg/m². She takes carbamazepine continuously for focal epilepsy and no other medication. A copper intrauterine device is clinically suitable and has been recommended, but she declines insertion after counselling and requests oral emergency contraception. Which oral regimen is most appropriate?

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

Reveal the answer and explanation

Correct answer: E — Give levonorgestrel 3 mg as a single dose now

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

Carbamazepine is a hepatic enzyme-inducing antiepileptic. It increases the metabolism of both ulipristal acetate and levonorgestrel and may reduce their emergency contraceptive effectiveness. FSRH recommends offering a copper IUD because its effectiveness is unaffected by enzyme induction. As she has declined this method, the recommended oral alternative is off-label double-dose levonorgestrel, 3 mg as a single dose. She should be advised that the effectiveness of this regimen in users of enzyme-inducing drugs is uncertain. B would ordinarily be attractive because intercourse occurred within 120 hours and close to the estimated fertile window; however, ulipristal acetate is not recommended during enzyme-inducer use. C is the standard levonorgestrel dose but is inadequate under FSRH guidance when hepatic enzyme induction is present. D represents intuitive dose escalation, but double-dose ulipristal acetate is not recommended because supporting evidence is lacking. E leaves a current pregnancy risk untreated: oral emergency contraception remains indicated within the relevant interval when the preferred copper IUD is declined. Pregnancy testing after 21 days may form part of follow-up but does not replace timely emergency contraception.

Reference: FSRH Clinical Guideline: Emergency Contraception (March 2017; amended July 2023) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-guideline-emergency-contraception03dec2020-amendedjuly2023-11jul.pdf FSRH Clinical Guideline: Emergency Contraception (March 2017; amended July 2023) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-guideline-emergency-contraception03dec2020-amendedjuly2023-11jul.pdf