Heavy Menstrual Bleeding (HMB) / Menorrhagia
Heavy menstrual bleeding (HMB) refers to excessive menstrual blood loss (as perceived subjectively by the individual) that interferes with physical, social, emotional, and/or material quality of life. It is a symptom rather than a diagnosis, and maybe caused by conditions such as fibroids and adenomyosis.
Updated UKMLA guide to HMB based on NICE NG88 and NICE CKS, covers causes, symptoms, assessment, investigation and management.
Definition and Terminology
HMB refers to excessive menstrual blood loss (as perceived subjectively by the individual) that interferes with physical, social, emotional, and/or material quality of life.
HMB is a symptom, not a disease or pathology itself. It may be caused by an underlying condition.
HMB and menorrhagia are broadly used to describe the same clinical concept and are often used interchangeably. However, latest medical practice, including NICE guideline, prefers the term ‘HMB’.
Traditionally, menorrhagia has been defined objectively as blood loss >80 mL and/or duration of >7 days. However, note that this definition is no longer considered useful, because measurement of menstrual blood loss is rarely undertaken in routine clinical practice and women’s self-assessment of blood loss has been widely demonstrated to differ from measured blood loss.
Causes
No cause is identified in ~50% cases of HMB.
Possible causes include:
| Uterine and ovarian pathologies |
|
| Systemic conditions |
|
The distribution of causes varies significantly by age group:
It is also worth being aware of the PALM-COEIN classification, developed by FIGO to classify causes of abnormal uterine bleeding, including HMB: [Ref]
- PALM (structural causes)
- P: polp
- A: adenomyosis
- L: leiomyoma
- M: malignancy and hyperplasia
- COEIN (non-structural causes)
- C: coagulopathy
- O: ovulatory dysfunction
- E: endometrial
- I: iatrogenic
- N: not yet classified
Clinical Features
As mentioned above, HBM is a subjective definition of excessive menstrual blood loss (by the patient), which interferes with physical, social, emotional and/or material quality of life.
Supportive features include:
- Soaking or having to change many pads / tampons per day (e.g. more than every 1-2 hours)
- Passage of large blood clots
- ‘Flooding episodes‘ where there is bleeding through clothes / sheets
- Features of iron deficiency anaemia (e.g. fatigue, pallor, dizziness, weakness)
Cause-specific clinical features:
| Cause of HBM | Supportive clinical features (non-exhaustive) |
|---|---|
| Fibroids | Common in women of reproductive age
|
| Adenomyosis | Common in 40-50 y/o (perimenopausal) women
|
| Endometrial polyps | Common in perimenopausal and postmenopausal women
|
Although endometriosis can cause HMB, it is NOT a main feature or main cause of HMB.
The predominant clinical manifestations of endometriosis are pelvic pain, dysmenorrhea, and deep dyspareunia.
Assessment and Diagnosis
Laboratory Tests
Perform FBC (to check for iron deficiency anaemia) in ALL patients
Consider the following (based on clinical context):
- Pregnancy test
- Clotting panel
- TFT
- Vaginal / cervical swabs
Work-Up for Underlying Cause
If the clinical examination is difficult or inconclusive (e.g. in women with obesity) when assessing for a possible underlying cause, offer a pelvic ultrasound.
Choice of investigations depends on the suspected underlying cause:
| Suspected pathology | Investigation |
|---|---|
| Submucosal fibroids |
|
| Polyps | |
| Endometrial pathology | |
| Large fibroids |
|
| Adenomyosis |
|
NICE specifically recommended the following:
- Do not use saline infusion sonography as a first-line diagnostic tool for HMB
- Do not use MRI as a first-line diagnostic tool for HMB
- Do not use dilatation and curettage alone as a diagnostic tool for HMB
Management
Referral Criteria
Referral to secondary care is indicated if:
- Suspected cancer
- >55 y/o with post-menopausal bleeding (due to possible endometrial cancer) (see the Endometrial Cancer article for more information)
- Ascites and/or pelvic or abdominal mass, which is not obviously due to uterine fibroids (due to possible ovarian cancer) (see the Ovarian Cancer article for more information)
- Fibroids that are ≥3cm or distorting the uterine cavity (consider referral as they may benefit from secondary care management) (see the Uterine Fibroids (Leiomyoma) article for more information)
- HMB failed to improve with primary care management
- Iron deficiency anaemia failed to respond to treatment, and other causes have been excluded
NICE recommends considering starting pharmacological treatment without investigating the cause if the history and/or examination suggest a low risk of fibroid / uterine cavity abnormality / adenomyosis.
Primary Care Management
The following management applies to HMB caused by:
- No identified pathology
- Fibroids that are <3 cm and NOT distorting the uterine cavity
- Adenomyosis
Choice of management is largely determined by whether the patient is planning to conceive (at the moment or in the near future).
| Patient’s conceiving wish | Recommended management |
|---|---|
| NOT planning to conceive |
|
| PLANNING to conceive | Offer non-hormonal treatment:
|
Key contraindications to LNG-IUS:
- History / current breast / cervical / endometrial cancer
- Unexplained, uninvestigated vaginal bleeding (due to possible endometrial cancer)
- Distorted uterine cavity (e.g. due to submucosal fibroids, intrauterine adhesions, large endometrial polyps, congenital uterine anomalies)
- Current PID
It is important not to mix up the role of copper IUD and LNG-IUS in HMB:
- Copper IUD can worsen or cause HMB
- LNG-IUS often causes oligomenorrhoea / amenorrhoea, thus used to treat HMB
References
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