Unscheduled bleeding on HRT
0Stop — call 999 now — or same-day emergency assessment
- Haemodynamic instability, or very heavy bleeding with collapse, syncope or cardiovascular compromise → 999
- Positive pregnancy test with pain, bleeding, syncope, shoulder-tip pain or peritoneal signs → Same-day ectopic pathway; unstable → 999
- Fever, pelvic pain or offensive discharge (esp. after IUS or instrumentation) → Same-day gynaecology; septic or unstable → 999
- Symptomatic severe anaemia, severe pelvic pain, torsion or acute abdomen → Same-day. Check observations, pregnancy test (HRT is not contraception), FBC if heavy, anticoagulants.
1Triage by BMS risk and timing — count risk factors first
| Finding | Action |
|---|---|
| 1 major / 3 minor | Suspected-cancer pathway, whatever the timing |
| 2 minor | Urgent TVUS ≤6 weeks |
| Heavy / prolonged | |
| Late or new | |
| Low risk, early | Adjust HRT; review at 3 months |
Heavy (at any time): >7 days, flooding, clots, most days ≥4 weeks. Late: first bleed >6 months after starting or >3 months after a change, after amenorrhoea on ccHRT, or a changed pattern. Low risk, early: no major, ≤1 minor, not heavy, within those windows.
Major: BMI ≥40 · Lynch/Cowden · oestrogen-only >6 months with a uterus · tricycling >12 months · sequential >5 years started at ≥45 · inadequate progestogen ≥12 months. Minor: BMI 30–39 · oestrogen-only 3–6 months · tricycling 6–12 months · inadequate progestogen 6–12 months · disproportionate progestogen >12 months · expired 52 mg LNG-IUS · PCOS · diabetes.
2Screen — one row is enough
- Postmenopausal bleeding not due to HRT timing: ≥55 → Suspected-cancer pathway; under 55 consider one (NG12).
- Suspicious cervix → Suspected-cancer pathway, not waiting for cytology. Persistent post-coital bleeding, normal cervix → local gynaecology pathway.
- Ascites or pelvic/abdominal mass not obviously fibroids → Suspected-cancer pathway, without waiting for CA-125. Ovarian-type symptoms aged 40+ → CA-125 (age-specific threshold) → urgent ultrasound.
- Any bleeding on tamoxifen → Suspected-cancer pathway.
3Assess
☐ HRT type, progestogen and days, duration, last change, adherence ☐ Timing vs progestogen phase, volume, post-coital ☐ BMI, abdomen, speculum, bimanual ☐ Screening status, tamoxifen. A smear is not a diagnostic test.
4Classify
- Expected — sequential: withdrawal bleed at the end of the progestogen phase, up to 7 days. ccHRT: spotting in the first 6 months or 3 months after a change.
- TVUS reassuring — ≤4 mm on ccHRT or ≤7 mm on sequential, fully seen and uniform → optimise HRT and review.
- TVUS abnormal — above threshold or incomplete view → Suspected-cancer pathway endometrial assessment. Polyp or focal lesion → gynaecology hysteroscopy.
- Atrophic vaginitis — pale, dry mucosa → vaginal oestrogen; new unexplained bleeding still needs assessment.
- Uncertain — say so; do not label it "HRT bleeding". Scan or refer, with a named review date.
5Treat today — low risk only
- Adherence and administration first; check the progestogen dose and days are adequate.
- Sequential: at least 10 days/month norethisterone or MPA, or 12 days micronised progesterone. Consider reducing oestrogen or an alternative progestogen.
- Consider a 52 mg LNG-IUS (prescribe by brand; change at 5 years for endometrial protection). Vaginal oestrogen for atrophy.
- Sequential started after 45: consider switching to continuous combined after 5 years or by age 54. Doses: NICE/SPC, BNF, local formulary.
6Refer routinely
- Persistent or recurrent bleeding despite a normal TVUS → gynaecology (usually hysteroscopy).
- Heavy breakthrough bleeding on sequential HRT despite optimisation → gynaecology.
- Regimen review, progestogen intolerance, pipelle → community gynaecology or menopause clinic.
7Never reassure by
- "It's the HRT" beyond 6 months, or 3 months after a change.
- A thin endometrium that was not fully seen.
- A normal pipelle when bleeding continues.
- Atrophy on examination or vaginal oestrogen use.
- A normal screening smear.
- Repeated HRT adjustment with no review date.
8Safety-net — say it, then document it
999 “Call 999 if you faint or collapse, or the bleeding is very heavy and you feel dizzy or unwell.” Same day: “Contact us today for severe pelvic pain, fever or smelly discharge, or a positive pregnancy test with pain or bleeding.” Back for a scan: “Tell us if the bleeding becomes heavy, lasts over 7 days, happens most days for 4 weeks, or has not settled when we review you at 3 months.”
Remote: book face to face — do not attribute bleeding to HRT, atrophy or the cervix without examination and investigation.