Contraception - assessment
Exam Tips
- In OSCEs, start by excluding pregnancy and asking about unprotected sex timing before method selection.
- Quote effectiveness correctly: typical-use failure is much lower for LARC than pills/condoms because adherence error is minimized.
- Always mention UKMEC for CHC/POP/IUC eligibility and key CHC red flags (migraine aura, VTE history, severe hypertension, smoking age >=35).
- For emergency contraception, remember: Cu-IUD is most effective; ulipristal 30 mg up to 120 hours; levonorgestrel 1.5 mg ASAP (licensed to 72 hours).
- Under 16 years: document Fraser competence, confidentiality discussion, and safeguarding assessment.
- See Figure: UKMEC category framework and contraceptive efficacy pyramid for rapid viva recall.
Definition
Contraception assessment is a structured, person-centred clinical consultation used to select a safe, effective, and acceptable method of preventing pregnancy. In UK practice it includes excluding current pregnancy, screening for contraindications using UKMEC/WHO MEC principles, assessing STI risk and safeguarding, and counselling on efficacy, adverse effects, interactions, and return to fertility.
Pathophysiology
Contraceptive methods reduce conception by different biological mechanisms: suppression of ovulation (combined hormonal contraception, desogestrel POP, injectable progestogens), thickening of cervical mucus (all progestogen-only methods), endometrial effects reducing implantation probability (progestogen methods), and direct spermicidal/intrauterine inflammatory effects (copper IUD). Method failure in real life is driven less by pharmacology than by adherence and user dependency, which is why long-acting reversible contraception (implant, IUD, IUS, injectable) has much lower typical-use failure than daily or pericoital methods. See Figure: contraceptive efficacy pyramid (LARC at the most effective tier).
Risk Factors
- Age under 25 years with higher STI exposure risk
- Multiple or new sexual partners, inconsistent condom use
- Smoking (especially age 35 years and over) increasing CHC cardiovascular risk
- Migraine with aura (important contraindication to CHC)
- Hypertension, obesity, prior VTE, thrombophilia, prolonged immobility
- Current or recent breast cancer (contraindication to hormonal methods, especially CHC/progestogens)
- Liver enzyme-inducing medicines (for example carbamazepine, phenytoin, rifampicin, St John’s wort) reducing efficacy of many hormonal methods
- Postpartum and breastfeeding status affecting method eligibility by timing
- Safeguarding vulnerability (under 16, coercion, exploitation, learning disability, social vulnerability)
Clinical Features
Symptoms
- Request for contraception with preference concerns (efficacy, bleeding pattern, hormones, privacy, reversibility)
- Possible pregnancy symptoms (missed period, nausea, breast tenderness)
- Symptoms suggesting STI (pelvic pain, dyspareunia, abnormal discharge, intermenstrual/postcoital bleeding)
- Headache history suggestive of migraine aura
- Heavy or painful periods influencing choice (for example LNG-IUS benefit)
- Concerns about weight change, mood change, acne, or libido with prior contraception
Signs
- Blood pressure measurement before CHC initiation
- BMI/weight as baseline and for risk stratification
- No routine pelvic exam needed for pills/patch/ring unless clinically indicated
- Abdominal/pelvic tenderness or cervical excitation if STI/PID suspected
- Clinical indicators of safeguarding concern (distress, inconsistent history, controlling partner presence)
Investigations
Management
Lifestyle Modifications
- Shared decision-making: discuss effectiveness (typical vs perfect use), adverse effects, non-contraceptive benefits, and return to fertility
- Offer all methods including LARC first-line for highest real-world effectiveness
- Promote dual protection: condoms plus effective contraception for STI and pregnancy prevention
- Smoking cessation and cardiovascular risk reduction before/alongside method choice
- Safeguarding assessment, confidential care, and Fraser competence assessment when under 16
- Provide clear written safety-net advice (missed pills, vomiting/diarrhoea, emergency contraception windows)
Pharmacological Treatment
Combined hormonal contraception (CHC)
- Ethinylestradiol 30 micrograms + levonorgestrel 150 micrograms oral tablet, 1 tablet daily for 21 days then 7-day break (or tailored/extended regimens)
- Ethinylestradiol/etonogestrel vaginal ring (one ring for 3 weeks, then 1 ring-free week)
- Ethinylestradiol/norelgestromin transdermal patch, changed weekly for 3 weeks then 1 patch-free week
Avoid if UKMEC category 4 (for example migraine with aura, current VTE, severe hypertension, smoker age >=35 with heavy smoking). Check interactions with enzyme inducers; counsel on VTE warning symptoms (leg swelling, pleuritic chest pain, sudden breathlessness).
Progestogen-only oral contraception (POP)
- Desogestrel 75 micrograms tablet once daily continuously
- Norethisterone 350 micrograms tablet once daily continuously
- Drospirenone 4 mg tablet once daily (24 active + 4 inactive regimen depending on product)
Useful when oestrogen is contraindicated. Enzyme-inducing drugs can reduce efficacy (method-specific advice needed). Irregular bleeding is common initially and should be pre-counselled.
Long-acting progestogen methods
- Etonogestrel implant 68 mg subdermal, effective for 3 years
- Medroxyprogesterone acetate 150 mg IM every 13 weeks
- Medroxyprogesterone acetate 104 mg SC every 13 weeks
- Levonorgestrel intrauterine system (for example 52 mg device, duration depends on product/licence)
Very low typical-use failure. Discuss delayed return to fertility with injectable use and possible bone mineral density concerns with prolonged depot medroxyprogesterone; review risks/benefits periodically.
Emergency contraception
- Levonorgestrel 1.5 mg orally as a single dose (as soon as possible, licensed up to 72 hours after UPSI; can be used up to 120 hours with lower efficacy)
- Ulipristal acetate 30 mg orally as a single dose within 120 hours of UPSI
Copper IUD is most effective emergency method and can be fitted up to 5 days after earliest expected ovulation (or within 5 days of UPSI per protocol). After ulipristal, delay restarting hormonal contraception for 5 days and use condoms meanwhile; avoid ulipristal in severe asthma on oral glucocorticoids and in breastfeeding without counselling on interruption.
Surgical / Interventional
- Copper IUD insertion (also emergency contraception option when indicated)
- Female sterilisation (tubal occlusion) after informed counselling on permanence and alternatives
- Male sterilisation (vasectomy) with post-procedure semen confirmation before relying on method
Complications
- Unintended pregnancy due to incorrect use, interactions, or delayed initiation
- Ectopic pregnancy risk if conception occurs with IUD in situ
- Venous thromboembolism, stroke, or myocardial infarction risk increase with CHC in high-risk groups
- Irregular bleeding, amenorrhoea, or method discontinuation from side effects
- Pelvic infection soon after IUD insertion (small absolute risk), expulsion, or uterine perforation (rare)
- Missed safeguarding concerns in under-16s or vulnerable adults
Prognosis
With a tailored method and good follow-up, contraceptive care is highly effective and safe, with rapid return to fertility after stopping most methods (except possible delay after depot medroxyprogesterone). Outcomes are best when counselling addresses adherence, interaction risks, and STI prevention in parallel.
Sources & References
✅NICE Guidelines(1)
- Contraception - assessment[overview]
📖Textbook References(20)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 44)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 43, 44)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1771)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 44)[context]
- Emergencies in - Obstetrics and Gynaecology, Second Edition (Stergios K. Doumouchtsis, S. Arulkumaran) (Z-Library).pdf(pp. 214, 215)[context]
- Emergencies in - Obstetrics and Gynaecology, Second Edition (Stergios K. Doumouchtsis, S. Arulkumaran) (Z-Library).pdf(pp. 215)[context]
- Emergencies in - Obstetrics and Gynaecology, Second Edition (Stergios K. Doumouchtsis, S. Arulkumaran) (Z-Library).pdf(pp. 215)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 227)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 591)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 2993, 2994)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 3055)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 2542, 2543)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 3055, 3056)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 3054, 3055)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 2543, 2544)[context]
- _OceanofPDF.com_Netters_Anatomy_-_8th_edition_-_Frank_H_Netter_MD.pdf(pp. 2481, 2482)[context]
- [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 379)[context]
- [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 378, 379)[context]
- [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 114)[context]
- [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 114)[context]