Menorrhagia

Menorrhagia is defined as a monthly menstrual blood loss in excess of 80ml. In reality, blood loss is measured only in a research situation and so the diagnosis is subjective and when blood loss has been measured, the volume lost has varied enormously.

The average menstrual cycle has a blood loss for 7 days of a cycle of between 21 and 35 days.
The usual shorthand for this is K= 7/21-35 in which K represents menstrual cycle, 7 is the duration of bleeding and 21-35 represents the length of the cycle. Menstrual loss is heaviest for the first few days and becomes much lighter, tailing off towards the end.
Other definitions to be borne in mind are:

• Metrorrhagia that is flow at irregular intervals
• Menometrorrhagia that is frequent and excessive flow
• Polymenorrhoea is bleeding at intervals of less than 21 days
• Dysfunctional uterine bleeding that is abnormal uterine bleeding without any obvious structural or systemic pathology
• Dysmenorrhoea is pain with menstruation

The average menstrual blood loss is about 35 to 40ml. Some researchers have found that no more than 10% of women who complain of heavy menstruation have blood loss in excess of 80ml. Menorrhagia is very subjective; a more practical definition may be that it is menstrual loss that is greater than the woman feels that she can reasonably manage.
Loss can be very heavy. In one study of 50 women, 12 had a monthly loss in excess of 200ml and 5 in excess of 450ml.¹

Menorrhagia is a very common complaint:

• 33% of women describe their periods as heavy
• 1 in 20 women aged 30 to 49 years consult their GP each year for heavy periods and menstrual disorders
• It is the second commonest gynaecological condition to be referred to hospital, accounting for 12% of all gynaecological referrals.

• 40 to 60% of those who complain of excessive bleeding have no pathology and this is called dysfunctional uterine bleeding.
• 20% of cases are associated with anovulatory cycles and these are commonest at the extremes of reproductive life.
• Local causes include:
  • Fibroids
  • Pelvic inflammatory disease
  • Carcinoma, especially endometrial carcinoma in women over 40; this usually presents with postmenopausal bleeding, but 20 to 25% of cases present with abnormalities of the menstrual cycle.
• Systemic disease can include hypothyroidism and bleeding disorders.
• An IUCD will increase menstrual flow and it has been claimed that sterilisation operations also increase loss. Prior to the operation women may have been taking oral contraceptives and, in comparison they make periods artificially light. Further studies have found that sterilisation does not increase menstrual loss.²

See Gynaecological history and examination.

• Note the total duration of bleeding and how much of that time it is heavy. Over 90% of menstrual loss occurs in the first 3 days and there is no correlation with the duration of loss and the total volume.¹
• Note the length of the cycle, i.e. the duration from the start of one period to the start of the next.
• If the patient has to wear tampons and towels simultaneously, flow is heavy.
• The passage of clots represents heavy flow. Clots may be painful as they pass through the cervix.
• Ask about premenstrual syndrome, intermenstrual bleeding, post-coital bleeding, dyspareunia and pelvic pain.
• Ask about intentions with regard to further children as this may affect management.
• Ask about easy bruising or bleeding gums.

Examination

• Note general appearance and BMI. Body fat is very important in relation to metabolism of steroid hormones.
• Note any signs suggestive of endocrine abnormality or bruising.
• Look at the tongue for pallor and the nails for koilonychia.
• Examination of the abdomen always precedes pelvic examination, or large pelvic masses can be missed.
• Ascertain that the cervical smear is up to date.
• Inspect the cervix and take swabs if clinically indicated.
• Perform a bimanual examination. Abnormalities may include a bulky or grossly enlarged uterus, fixation of the uterus or tenderness.

• Women can be asked to complete a pictorial representation to assess the volume of blood loss.³ The accuracy has been validated against objective measurement.⁴ Women who complain of menorrhagia but whose loss is not excessive can be helped to avoid surgery whilst those whose loss is genuinely heavy can be identified and are more likely to be satisfied by surgery.⁵
• FBC is important. The commonest cause of iron deficiency anaemia is menorrhagia.
• Tests for endocrine abnormalities, including thyroid function tests should be performed only if there is clinical suspicion.
• Assessment of bleeding disorders is only indicated if there is clinical suspicion.

Not everyone needs referral to secondary care. Patients are referred to exclude sinister pathology and when treatment in primary care has failed.

• If history and FBC are reassuring, then drug treatment should be considered if required. All drug treatments preserve fertility.
• If history is persistent IMB, or the patient is 45 years or over and medical treatments have failed refer for endometrial biopsy.
• If the uterus is palpable per abdomen, or there is a pelvic mass, refer for ultrasound.

Drug

• If there is iron deficiency it should be corrected with oral iron.
• First line treatment is the levonorgestrel intra-uterine system - Mirena®. This is long-term treatment and should be left in situ for at least 12 months.⁶
• If this is unacceptable to the patient then consider tranexamic acid, NSAIDs or the combined oral contraceptive.⁶
• NSAIDs reduce uterine prostaglandin levels and can reduce flow by 20 to 50% as well as reducing dysmenorrhoea.⁷ The medication is taken only during menstruation.
• Tranexamic acid is a plasminogen-activator inhibitor. It inhibits the dissolution of thrombosis that leads to menstrual flow. It can reduce flow by up to 50% although there is little correlation between the extent of reduced flow and patient satisfaction.⁸
• Combined oral contraceptives reduce menstrual flow but data is poor.⁹ Be aware that the schoolgirl complaining of intolerable periods may be a surreptitious request for oral contraceptives.
• Norethisterone is third-line therapy. Dose is 15mg tds, from day 5 to 26 (or injected long acting progestogens).
• Consider 3-4 months of a gonadotrophin-releasing hormone analogue (GRHA) before hysterectomy or myomectomy where the uterus is enlarged or distorted by fibroids. It is also a reasonable choice of therapy if other methods are contraindicated - but "addback" hormone therapy will be needed if continued for >6 months. Remember to stop GRHA before an uterine artery embolisation.

Surgical options

The choice of treatment will depend on both the uterine size and the patient's desire to retain her uterus.

• Endometrial ablation is the recommended first-line treatment if the uterus is <10 weeks gestation to palpate. This involves removing the full thickness of the endometrium together with the superficial myometrium, and the basal glands thought to be the focus of endometrial growth. It retains the uterus.
• If the uterus is > 10 week size, and the woman wishes to retain her uterus treatment options are uterine artery embolisation or hysteroscopic myomectomy.
• If the patient does not wish to retain the uterus, then hysterectomy - first consider vaginal, then abdominal with conservation of ovaries if appropriate.