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Ten top tips on unexpected vaginal bleeding

1. Rule out serious pathology first

Do this before considering how to manage bleeding caused by contraception, or idiopathic bleeding.

2. Exclude pregnancy as a cause

Ectopic pregnancy, early miscarriage and normal pregnancy can all present with vaginal bleeding. If the bleeding is associated with pain and a delayed recent period, consider admission to gynaecology for exclusion of ectopic pregnancy.

3. Consider infection as a cause

Both chlamydia and gonorrhoea can cause postcoital and intermenstrual bleeding. Risk factors for these would include age under 25 and recent change of partner or more than one partner in last year, but diagnoses in older age groups are becoming more common so you should have a high index of suspicion. A self-taken vaginal swab for polymerase chain reaction (PCR) would be reliable in terms of ruling out infection, but if the patient has associated systemic symptoms (nausea or temperature) or pelvic and abdominal pain they need speculum and bimanual examination for signs of pelvic inflammatory disease.

4. Remember cervical pathology as an important cause of unscheduled bleeding, particularly postcoitally

There are around 50 cases per year of cervical cancer in under-25s in the UK, and diagnosis is frequently delayed because they are not examined after they report abnormal bleeding. These patients need examination and referral to colposcopy or a two-week-wait gynaecology clinic if they have an abnormal looking cervix with features suggestive of cancer. It is important to remember that a cervical smear is not a diagnostic test for cancer and in fact can miss advanced lesions if there is a lack of cellular material in the sample. There is no evidence for performing smears early in women who are having abnormal bleeding, but if examination is suspicious they should be referred via the two-week rule to gynaecology/colposcopy.

Other cervical lesions such as ectropion, polyp, and cervical warts can cause unscheduled bleeding and these patients can be referred routinely to gynaecology for management.

5. Consider endometrial pathology in women with heavy menstrual bleeding or intermenstrual bleeding

Endometrial cancer is rare in women of reproductive age, and use of hormonal contraception reduces the risk but is not completely protective. The Royal College of Obstetricians and Gynaecologists recommends that women aged 45 or over with persistent problematic bleeding or a change in bleeding pattern should be referred for endometrial biopsy. This may also be indicated in women under 45 with persistent symptoms and risk factors for endometrial cancer (obesity, type 2 diabetes, PCOS). In premenopausal women, ultrasound alone is insufficient to exclude endometrial cancer but can be helpful where structural abnormality (polyps or fibroids) is suspected.

6. There are several strategies to improve unscheduled bleeding caused by combined hormonal contraception

Irregular bleeding is less common than with progesterone-only methods, and usually settles with time. There is no indication to switch combined oral contraceptives (COCs) in the first three months if irregular bleeding is a problem.

If unscheduled bleeding continues beyond this:

  • Increase ethinyl-oestradiol content – control is better with pills containing 30-35µg.
  • Change the type of progesterone – individual studies show pills containing gestodene (Femodene/Millinette) provide better control.
  • Try a COC with extended cycle (such as Qlaira or Zoely, which have a pill-free interval of four days). These pills also contain oestradiol instead of ethinyl-oestradiol and may improve bleeding because of this as well.
  • Try a tailored regime – advise women to take the pill continuously until bleeding starts and when they have been bleeding for more than three days, to stop. They should then have three pill-free days and restart, and take the pill until the next episode of bleeding, ensuring that a minimum of 21 days elapse before the next pill-free interval.
  • Cycle control is better with a vaginal ring than with a pill or patch. 

7. When counselling women for use of progesterone methods, discuss the fact that unscheduled bleeding is common and unfortunately may be considered normal

As a guide, after 12 months’ use of desogestrel pills for any given three-month period:

  • Five in 10 women will be amenorrhoeic or have infrequent bleeding.
  • Four in 10 can expect three to five bleeding/spotting episodes.
  • One in 10 has more than six episodes.
  • Two in 10 of these women might have bleeding/spotting lasting more than 14 days at a time.

For women who are having prolonged and frequent bleeding, swapping to a traditional progestogen-only pill (POP), which is more likely to give frequent short bleeds, may help. In clinical practice using two of either pill a day has been reported to help but this has not been demonstrated in studies.

8. Counselling prior to Nexplanon insertion may help improve continuation rates

Bleeding with Nexplanon tends to be similar to the above pattern but can change with time, often settling in the first six months and deteriorating again in the last 12 months. Irregular bleeding often reduces duration of use, and counselling prior to insertion may help improve continuation.

Adding oestrogen in the form of the COC has been shown to be helpful – either cyclically or constantly for three months. There is no evidence from RCTs on the effects of long-term use but I have prescribed the pill for long-term use (where there are no contraindications) for women who prefer the contraceptive efficacy of the implant but have persistent bleeding problems with it.

Mefenamic acid 500mg bd can reduce the length of bleeding episodes but has no effect on frequency of episodes.

There is no evidence for tranexamic acid on unscheduled bleeding.

9. These strategies are effective for irregular bleeding with the IUS

A 90% reduction in menstrual loss has been demonstrated after a year of IUS use, so long-term unscheduled bleeding with Mirena should prompt re-investigation of infection, placement of the device, and consideration of risk of endometrial hyperplasia as the cause of the bleeding.

Use of Jaydess is associated with more bleeding days and prolonged light periods are considered normal.

10. Where there is no other cause, a three to six-month trial of hormonal treatment is reasonable

In women who are not using contraception, have normal examination, screening history and negative infection screen with no risks for endometrial hyperplasia, it is reasonable to treat with COCs, Mirena or norethisterone 5mg tds on days five to 25 for up to six months.

Dr Ruth Aynsley is a GP in Gateshead, Tyne and Wear, and an associate specialist in sexual health and contraception. No conflicts of interest declared


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