UKMEC guide
Category 4
do not initiate or continue; choose a non-hormonal or non-oestrogenic alternative.
If a patient develops a new Category 4 condition while already using the method, switch promptly and cover with back-up contraception.
Category 3
WHO/US-MEC: “Usually not recommended – clinical judgment and careful follow-up are required because theoretical or proven risks generally outweigh the advantages.”
Patients who have only category 3 factors should normally be steered to a progestogen-only or non-hormonal option; CHC may be used only if no safer method is acceptable and the provider can monitor the risk.
UKMEC Category 3 & 4 Contraindications by Contraceptive Method
| Method | Category 4 (Absolute CI) | Category 3 (Relative CI / Specialist Use) |
|---|---|---|
| Combined Hormonal Contraception (CHC) (COC pill, ring, patch) | – Current breast cancer – Migraine with aura (any age) – SBP ≥160 or DBP ≥100 mmHg – VTE (current, unanticoagulated) – Recurrent VTE – Known thrombogenic mutations – Stroke/TIA or IHD – Severe liver disease, hepatoma – Major surgery with prolonged immobility – Complicated valvular disease – SLE with antiphospholipid antibodies | – Past breast cancer – BMI ≥35 kg/m² – Controlled HTN (SBP 140–159 or DBP 90–99) – Smoking ≥35 yrs + <15 cig/day – Migraine without aura ≥35 yrs – Diabetes with complications – Gallbladder disease (symptomatic) – Dyslipidaemia – FHx VTE in 1st-degree relative <45 yrs |
| Progestogen-Only Pill (POP) | – Current breast cancer | – Past breast cancer – Severe liver disease – Hepatic adenoma/carcinoma – Unexplained vaginal bleeding |
| Progestogen Implant | – Current breast cancer | – Past breast cancer – Severe liver disease – Hepatic adenoma/carcinoma – Unexplained vaginal bleeding |
| DMPA Injection | – Current breast cancer | – Past breast cancer – Severe liver disease – Hepatic adenoma/carcinoma – Unexplained vaginal bleeding – Diabetes with complications – IHD or stroke – SLE with antiphospholipid antibodies |
| Intrauterine Device (Cu-IUD) | – Current PID (initiation) – Postpartum/postabortion sepsis – Unexplained vaginal bleeding (malignancy suspected) – Gestational trophoblastic disease with persistently elevated hCG | – Distorted uterine cavity – Cervical/endometrial cancer awaiting treatment – Severe thrombocytopenia/bleeding risk |
| Levonorgestrel IUS (LNG-IUS) | – Current PID (initiation) – Postpartum/postabortion sepsis – Unexplained vaginal bleeding (malignancy suspected) – Current breast cancer – Gestational trophoblastic disease with persistently elevated hCG | – Past breast cancer – Distorted uterine cavity – Severe liver disease – IHD or stroke – SLE with antiphospholipid antibodies – Cardiomyopathy with impaired function – Cervical/endometrial cancer awaiting treatment |
| Emergency Contraception (Cu-IUD) | – Current PID – Sepsis – Gestational trophoblastic disease (elevated hCG) – Distorted uterine cavity | – Cervical/endometrial cancer – Bleeding disorders |
| Emergency Contraception (Ulipristal / LNG) | None absolute | – Past breast cancer (caution) – Severe liver disease (theoretical for UPA) – CYP3A4 interactions (for UPA efficacy) |
🟥 Combined Hormonal Contraception (pill / patch / ring)
– Category 4
| Absolute CI | Mechanism of harm (one-line rationale) |
|---|---|
| Current breast cancer | Oestrogen/progestogen stimulation of hormone-receptor-positive tumour cells. |
| Migraine with aura (any age) | Aura signals cerebral vasospasm; oestrogen multiplies ischaemic-stroke risk ≈6-fold. |
| Severe hypertension ≥160/100 mmHg | Augments endothelial damage → stroke & MI. |
| Current or recent (<3 m) VTE/PE OR VTE not yet therapeutic on anticoagulation | CHC ↑ hepatic coagulation-factor synthesis → further thrombosis. |
| Known high-risk thrombogenic mutation (e.g. Factor V Leiden, prothrombin G20210A, antithrombin, protein C/S deficiency) | Baseline VTE risk magnified by added oestrogenic hypercoagulability. |
| History of stroke, TIA or ischaemic heart disease | Established arterial disease → CHC raises recurrence risk. |
| Major surgery with ≥1 week immobilisation | Synergy of post-op stasis + oestrogenic hypercoagulability. Cease ≥4 w pre-op. |
| Complicated valvular heart disease (pulmonary HTN, AF, prior endocarditis, cyanosis) | High embolic burden; CHC increases clot formation. |
| Decompensated cirrhosis / hepatocellular adenoma or carcinoma | Impaired metabolism ± tumour growth promotion by oestrogen. |
| Systemic lupus erythematosus with antiphospholipid antibodies or previous thrombosis | Extreme arterial & venous thrombotic propensity exacerbated by CHC. |
| Current smoker ≥15 cigs/day and ≥35 y | Dose-dependent acceleration of atherothrombosis with CHC. |
| Post-partum <21 days (regardless of feeding) | Peak puerperal hypercoagulability compounded by oestrogen. |
| Diabetes with micro- or macro-vascular complications | Additional vascular and thrombotic burden. |
🟥 Category 3
| Condition (WHO/US-MEC 3) | One-line rationale |
|---|---|
| Smoking ≥ 35 y & < 15 cigarettes/day | Synergistic arterial thrombosis risk, but lower than heavy smoking (cat 4). FHI 360 |
| Migraine without aura if ≥ 35 y | Stroke risk doubles vs baseline; aura would make it cat 4. CDC |
| Elevated BP 140-159 / 90-99 mmHg (controlled HTN) | Adds to oestrogen-induced BP rise and vascular risk. FHI 360 |
| History of DVT/PE on stable anticoagulation (therapeutic or prophylactic) | Anticoagulation partly mitigates risk, but oestrogen still prothrombotic. CDC |
| Past breast cancer (> 5 y, no recurrence) | Theoretical tumour stimulation—current cancer is cat 4. CDC |
| Diabetes ≥ 20 y OR with nephro-, retino-, neuro-pathy | Microvascular disease predicts macro- events with CHC. CDC |
| Multiple major CVD risk factors (e.g. age > 35, obesity, dyslipidaemia, strong FHx) | Aggregate risk exceeds benefit. FHI 360 |
| Symptomatic or medically-treated gall-bladder disease | Oestrogen slows bile flow and may precipitate relapse. CDC |
| Acute viral hepatitis / hepatitis flare | Transient hepatic enzyme derangement impairs oestrogen metabolism. FHI 360 |
| Bariatric surgery with malabsorptive procedure | Oral CHC absorption unreliable; patch/ring not affected. CDC |
| Enzyme-inducing drugs (rifampicin/rifabutin, phenytoin, carbamazepine, topiramate, etc.) | ↑ CHC clearance → contraceptive failure; use non-EI method. FHI 360 |
| Post-partum 21-42 days with additional VTE risk factors (obesity, transfusion, immobility) | Persisting puerperal hyper-coagulability. CDC |
| Chronic kidney disease on dialysis or nephrotic syndrome | Fluid shifts, thrombosis, and hormonal clearance issues. CDC |
🟧 Systemic Progestogen-Only Methods (POP, etonogestrel implant, DMPA)
Category 4
| Absolute CI | Rationale |
|---|---|
| Current breast cancer | Progestogens (even at lower serum levels) can stimulate tumour progression in hormone-receptor-positive disease. |
Category 3
| Condition | Why category 3? |
|---|---|
| Past breast cancer (> 5 y, no evidence of disease) | Any residual hormone-responsive cells could be stimulated. CDC |
| Severe (decompensated) cirrhosis / active liver tumours | Impaired progestogen metabolism & potential tumour growth. FHI 360 |
| Acute hepatitis flare | Temporarily reduced clearance; reassess once liver tests normalise. FHI 360 |
| Unexplained abnormal vaginal bleeding (pending diagnosis) | Need to exclude malignancy or structural cause first. FHI 360 |
| Diabetes with vascular complications or > 20 y duration (DMPA, implant) | Possible acceleration of CVD; POP is cat 2. CDC |
| Concomitant potent enzyme-inducing drugs (POP & implant) | Marked fall in serum progestogen → efficacy uncertain. FHI 360 |
| Severe thrombocytopenia (DMPA injection) | IM injection bleeding risk; consider implant/POP instead. FHI 360 |
(POPs/implants remain category 1–2 for most thrombotic or cardiovascular conditions; they are acceptable when CHC is contraindicated.)
🟦 Intra-Uterine Contraception
— Category 4
| Absolute CI (both Cu-IUD & LNG-IUS unless labelled) | Rationale |
|---|---|
| Pregnancy (known or suspected) | Insertion can cause miscarriage or sepsis. |
| Current PID / purulent cervicitis / puerperal or post-abortal sepsis | Risk of ascending infection and septic shock. |
| Unexplained heavy or irregular bleeding suspicious for malignancy | May mask diagnosis; perforation/bleeding risk. |
| Untreated cervical or endometrial cancer | Instrumentation may disseminate malignancy or trigger haemorrhage. |
| Gestational trophoblastic disease with persistently ↑ hCG | Increased perforation and haemorrhage risk; metastatic spread concern. |
| Distorted uterine cavity (large fibroids, congenital anomaly, adhesions) | Prevents correct placement → perforation or expulsion. |
| Pelvic tuberculosis | High risk of severe pelvic infection post-insertion. |
| Current breast cancer (☞ LNG-IUS only) | Systemic levonorgestrel exposure can stimulate tumour cells. |
Category 3
| Condition (both Cu-IUD & LNG-IUS unless specified) | Practical concern |
|---|---|
| 48 h – < 4 weeks post-partum | Uterus still involuting → higher expulsion/perforation risk. FHI 360 |
| Very high ongoing STI risk (e.g. multiple partners, recent STI, sex-work) | Elevated chance of ascending infection (but can insert if risk is mitigated). FHI 360 |
| Severe thrombocytopenia or bleeding disorder | Trauma-related haemorrhage from insertion or removal. CDC |
| Cervical intra-epithelial neoplasia / cervical cancer awaiting treatment → Cu-IUD cat 4, LNG-IUS cat 3 | IUD may provoke bleeding/infection; LNG-IUS sometimes used therapeutically for bleeding control. CDC |
| Persistent unexplained but not suspicious abnormal bleeding | Need diagnosis first; malignancy-suspect bleeding is cat 4. FHI 360 |
| Gestational trophoblastic disease with regressing or undetectable β-hCG | Uterus delicate; wait until β-hCG normal & uterus involuted. CDC |
| Pelvic tuberculosis | Insertion may seed infection into endometrium → infertility risk. FHI 360 |
Copper-IUD as Emergency Contraception
All of the above IUD absolute contraindications apply at the time of urgent insertion, especially: pregnancy, active PID/sepsis, uterine distortion, and persistent trophoblastic disease
The same Category 3 rules apply at the point of urgent insertion (especially postpartum 48 h-<4 wk, high STI risk, severe thrombocytopenia). Pregnancy, acute PID or sepsis, and distorted cavity remain Category 4 absolute contraindications.
Using this list in practice
- Screen for Category 4 first; if none, check for Category 3.
- If only Category 3 factors exist, discuss alternative methods or enhanced precautions/monitoring.
- Document the shared decision-making discussion and plan follow-up.