Menorrhagia is an abnormally heavy and prolonged menstrual period. Causes may be due to abnormal blood clotting, disruption of normal hormonal regulation of periods or disorders of the endometrial lining of the womb. Depending upon the cause, it may be associated with abnormally painful periods (dysmenorrhoea).

Definition

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A normal menstrual cycle is 21-35 days in duration, with bleeding lasting an average of 7 days and total blood flow between 25 and 80 mL. A blood loss of greater than 80 ml or lasting longer than 7 days constitutes menorrhagia, although in practice this is never directly measured by patients or doctors. Menorrhagia also occurs at predictable and normal (usually about 28 days) intervals, distinguishing it from hypermenorrhea, which occurs at predictable intervals that are not of the normal length.

Complications

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Aside from the social distress of dealing with a prolonged and heavy period, over time the blood loss may prove to be greater than the body iron reserves or the rate of blood replenishment, leading to anemia. Symptoms attributable to the anemia may include tiredness, weakness, tingling and numbness in fingers and toes, headaches, depression, becoming cold more easily, and poor concentration.

Etiology

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Usually no causative abnormality can be identified and treatment is directed at the symptom, rather than a specific mechanism. A brief overview of causes is given below, followed by a more formal medical list based on the nature of the menstrual cycle experienced.

Disorders of coagulation

With the shedding of the endometrial lining's blood vessels, normal coagulation process must occur to limit and eventually stop the blood flow. Blood disorders of platelets (such as ITP) or coagulation (such as von Willebrand disease) or use of anticoagulant medication (such as warfarin) are therefore possible causes, although a rare minority of cases.

Excessive build up in endometrial lining

Periods soon after the onset of menstruation in girls (the menarche) and just before menopause may in some women be particularly heavy. Hormonal disorders involving the ovaries-pituitary-hypothalamus (the 'ovarian endocrine axis') account for many cases, and hormonal-based treatments may regulate effectively.

Naturally the lining of the womb builds up under the hormonal effects of pregnancy, and an early spontaneous miscarriage may be mistaken for a heavier than normal period.

Irritation of the endometrium may result in increased blood flow, e.g. from infection (acute or chronic pelvic inflammatory disease) or the contraceptive intrauterine device (note the distinction from the IntraUterine System which is used to treat this condition).

Fibroids in the wall of the womb sometimes can cause increase menstrual loss if they protrude into the central cavity and so thereby increase endometrium's surface area.

Abnormalities of the endometrium such as adenomyosis (so called "internal endometriosis") where there is extension into the wall of the womb gives rise to enlarged tender uterus. Note, true endometriosis is a cause of pain (dysmenorrhoea) but usually not alteration in menstrual blood loss.

Endometrial carcinoma (cancer of the uterine lining) usually causes irregular bleeding, rather than the cyclical pattern of menorrhagia. Bleeding in between periods (intermenstrual bleeding or IMB) or after the menopause (postmenopausal bleeding or PMB) should always be considered suspicious.

Consideration by nature of the menstrual cycle

• Excessive menses but normal cycle:
  • Painless:
    • Fibroids
    • Ovarian endocrine disorder (dysfunctional uterine bleeding or DUB)
    • Coagulation defects (rare)
  • Painful:
    • Pelvic inflammatory disease
    • Endometriosis
• Short cycle (<21 days) but normal menses (epimenorrhoea or polymenorrhoea). These are always anovulatory cycles due to hormonal disorders.
• Short cycle and excessive menses (epimenorrhagia) due to ovarian dysfunction and may be secondary to blockage of blood vessels by tumours.
• Excessive menses and long intervals.
  • Anovular ovarian disorder due to prolonged oestrogen production.
  • This may occur following prolonged continuous courses of the combined contraceptive pill (e.g. where several packets are taken without a withdrawal gap to defer menstruation for holidays or before a woman's wedding).

Treatment

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Where an underlying cause can be identified, treatment may be directed at this. Clearly heavy periods at the start and end of a women's reproductive years may settle spontaneously (the menopause being the cessation of periods).

If the degree of bleeding is mild, all that may be sought by the woman is the reassurance that there is no sinister underlying cause. If anaemia occurs then iron tablets may be used to help restore normal haemoglobin levels. Treatment may be given for a fixed period of time to replenish the body stores. Alternatively therapy may be continued long-term, often in a cyclical regimen on the days of menstruation.

The condition is often be treated with hormones, particularly as dysfunctional uterine bleeding commonly occurs in the early and late menstrual years when contraception is also sought. Usually oral combined contraceptive or progesterone only pills may be taken for a few months, but for longer-term treatment the alternatives of injected Depo Provera or the more recent progesterone releasing IntraUterine System may be used. Fibroids may respond to hormonal treatment, else require surgical removal.

Anti-inflammatory medication has previously been used, although it has a greater effect on dysmenorrhoea excess pain than on the heaviness of the period (typically 30% reduction in flow). More effective is the use of tranexamic acid tablets that may reduce loss by up to 50%. This may be combined with hormonal medication previously mentioned.

A definitive treatment for menorrhagia is to perform hysterectomy (removal of the uterus). This historically has been associated with issues of male domination within medicine and patient's subservient roles. The risks of the procedure have been reduced with measures to reduce the risk of deep vein thrombosis after surgery, and the switch from the front abdominal to vaginal approach greatly minimising the discomfort and recuperation time for the patient; however extensive fibroids may make the womb too large for removal by the vaginal approach. Small fibroids may be dealt with by local removal (myomectomy). A further surgical technique is endometrial ablation (destruction) by the use of applied heat (thermoablation). A non-surgical approach has been the introduction and use of the IntraUterine System.

In the UK the use of hysterectomy for menorrhagia has been almost halved between 1989 and 2003. This has a number of causes: better medical management, endometrial ablation and particularly the introduction of IUS which may be inserted in the community and avoid the need for specialist referral; in one study up to 64% of women cancelled surgery.

References

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1. Trends in number of hysterectomies performed in England for menorrhagia: examination of health episode statistics, 1989 to 2002-3 - Peter C Reid and Faizah Mukri - BMJ 2005; 330: 938-939 Full text
2. Clinical Outcomes and Costs With the Levonorgestrel-Releasing Intrauterine System or Hysterectomy for Treatment of Menorrhagia, 2004 Randomized Trial 5-Year Follow-up - JAMA Vol. 291 No. 12, March 24/31 Abstract
3. Treatment of menorrhagia with the levonorgestrel intrauterine system versus endometrial resection. Istre O, Trolle B. - Fertil Steril. 2001 Aug;76(2):304-9. PMID 11476777
4. The effectiveness of the levonorgestrel-releasing intrauterine system in menorrhagia: a systematic review. Stewart A, Cummins C, Gold L, Jordan R, Phillips W. - BJOG. 2001 Jan;108(1):74-86. PMID 11213008
5. Feig, Robert L. and Nicole C. Johnson. First Aid for the Obstetrics and Gynecology Clerkship. ISBN 0-07-136423-4.

• Continuous Identification of Research Evidence (collaborative of the WHO, and US CDC & Johns Hopkins Hospital) - Search of Evidence about the IUS

Gynecology | Menstruation | Menorragia