Introduction

Intermenstrual bleeding (IMB) is a presentation, rather than a diagnosis, and can be indicative of a number of underlying disorders.

It refers to vaginal bleeding at any time during the cycle, except during menses.

Breakthrough bleeding is a separate term that refers to vaginal bleeding whilst on hormonal contraception at a time other than the withdrawal bleed seen with the pill.

It is often considered together with postcoital bleeding (PCB), as the two symptoms may present together and have overlapping causes, although differentiating between the two can help to narrow down the possible differentials.

Intermenstrual bleeding is important because cerrvical cancer should always be considered, although in reality, this is rare – especially in young women.

Epidemiology

  • About 15% of women experience abnormal uterine bleeding
  • Two-year cumulative incidence for IMB is about 25%
  • Up to half of cases resolve spontaneously
  • The association with uterine cancers is low, but is often a concern for patients
  • Many women present with a combination of IMB and PCB

Causes

  • Infection
  • Cervical ectropion (aka cervical erosion)
    • More common in younger women, and those on the pill
  • Cervical or endometrial polyps
  • Contraception
    • IUD
    • Oral contraceptive pill
  • Cancers
    • Cervical
    • Endometrial
    • Vaginal
    • Ovarian (especially if oestrogen secreting
  • Atrophic vaginal change
  • Physiological
    • 2% of women will have spotting around ovulation
  • Breakthrough bleeding when taking hormonal contraception
    • More common with progesterone only methods, or combined methods with <30 micrograms of ethinylestradiol (oestrogen)
  • Rarer causes(more commonly associated with menorrhagia rather than intermenstrual bleeding)

History

  • Menstrual history
    • Last menstrual period (LMP)
    • Cycle regularity and length
    • Duration of bleeding
    • Heaviness of bleeding
    • Any menorrhagia?
    • Any vaginal discharge?
    • Any fevers?
    • Any pelvic pain?
  • Contraceptive history
    • What is she using?
    • For how long
    • Any correlation with symptoms?
    • History of cervical screening tests
  • Sexual history
    • History of STI screening tests
  • Reproductive history
    • Previous pregnancies and deliveries
    • Is she currently breastfeeding?
  • Confirm bleeding is from the vagina
    • If uncertainty – use a tampon next time bleeding occurs to confirm

Examination

  • Abdominal exam
    • Check for pelvic masses
  • Vaginal examination
    • Polyps?
    • Presence of blood or a bleeding site
    • Cervical ectropion
    • Discharge
    • Cervicitis
      • Usually caused by chlamydia, less commonly gonorrhoea
      • Herpetic cervicitis often has multiple ulcers
      • Trichonmonas vaginalis can cause a friable inflamed cervix also
  • BMI – if high – this is an independent risk factor for endometrial cancer

Investigations

  • Cervical smear and HPV testing
  • Consider STI screening (i.e. high vaginal swabs) if any vaginal discharge, pain, or risk factors for STI
  • Pregnancy test – ALWAYS confirm no pregnancy in the context of abnormal uterine bleeding
  • Referral to gynaecology for colposcopy if no cause apparent with the above
  • USS
    • Transvaginal is most accurate
    • Ideally done immediately after the end of the period – as endometrial thickness can be measured at this point
    • Any endometrial thickening (>12mm in pre-menopausal women and >5mm in peri-menopausal women) requires prompt referral to gynaecology
  • Endometrial biopsy
  • Women with ongoing heavy intermenstrual bleeding should be referred for hysteroscopy with endometrial biopsy

When to refer for specialist assessment

  • Abnormal cervical appearance – need an urgent referral for cervical cancer assesment
  • Cervical polyp that cannot be easily removed on speculum examination
  • Pelvic mass on abdominal examination or USS
  • Those at high risk of cervical cancer
    • FHx of cervical cancer
    • On tamoxifen
    • Heavy intermentrual bleeding
  • ANY woman aged over 45 with persistent symptoms (>3 months duration)

Management

Overall, about half of cases resolve spontaneously.

Otherwise, treatment depends on the cause:

  • Suspected cancer – urgent referral to gynaecology
  • Infection – treat the infection
  • Breakthrough bleeding
    • Ensure the contraceptive method is being used correctly
    • Is normal in the first 3 months of use of any type of hormonal contracpetion
    • Consider increasing the oestrogen content of the contraception used – e.g. if on a pill with 20mcg daily of ethinylestradiol, increase this to 30-35mcg
    • If using the IUS or depot injection – consider also adding combined hormonal contraceptive pill for 3 months
    • Mefanamic acid or tranexamic acid can be used for symptom control as required
  • Cervical ectropion
    • Usually resolve if the pill is stopped
    • Can be cauterised with silver nitrate
    • May also be treated with diathermy, laser or microwave therapy
  • Cervical and endometrial polyps
    • Can be removed during speculum examination if visible – but twisting and pulling at the stem (this is usually painless). They should be sent for histology
    • Cervical cancer risk for polyps:
      • 1-2% for pre-menopausal women
      • 5% for post-menopausal women
  • Fibroids
    • Can be removed during hysteroscopy
    • Uterine artery emobilisation is alo effective

References

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