ORGANUM
Heavy menstrual bleeding (HMB) is defined in research studies as more than 80 mL per month of loss, affects approximately 10% of women. The recommended 'clinical' definition of HMB (for use in the clinic) is 'excessive menstrual loss leading to interference with the physical, emotional, social and material quality of life of a women, which occurs alone or in combination with other symptoms'. HMB should be recognised as having a major impact on a woman's quality of life. Although HMB is usually caused by benign conditions, it commonly leads to iron-deficiency anaemia, which can be part of the serious impact on a woman's social, family and working life (through the burden of managing the practical difficulties of excessive blood loss and having to curb normal activities). HMB can commonly arise from an imbalance in the clotting and other regulatory molecular factors at a local endometrial level, without the presence of obvious structural pathology. However, it also can be associated with a number of benign gynaecological conditions, including leiomyomata, endometrial polyps, adenomyosis, endometrial hyperplasia and sometimes endometrial cancer.
Leiomyomata are the commonest structural lesions to cause heavy regular bleeding, although most women with fibroids do not experience abnormal loss. Endometrial carcinoma is rare under the age of 40 years and is more likely initially to cause irregular bleeding. Adenomyosis is usually associated with a uniformly enlarged tender uterus, HMB and dysmenorrhoea. Endometrial polyps are a common cause of HMB but usually also cause IMB. Endometrial hyperplasia is a common structural cause causing HMB and may be associated with irregular, anovulatory cycles. It may be a premalignant condition. It may also overlap with disturbed ovulation syndromes.
Disturbed ovulation of anovulation can result in very irregular, especially infrequent cycles with prolonged, heavy and irregular bleeding of such severity that it may occasionally be life threatening. In this situation, unopposed oestrogen often leads to the endometrium becoming greatly thickening and often hyperplastic. This unstable endometrium eventually breaks down in a patchy and erratic fashion. Most ovulatory disorders occur in the menopause transition and in adolescence or can be traced to endocrinopathies - PCOS and hypothyroidism
When there is regular heavy bleeding with no underlying structural lesion, HMB is usually the result of a primary endometrial disorder where the mechanism regulating local endometrial 'haemostasis' are disturbed. There may be excessive local production of fibrinolytic factors (especially tissue plasminogen activator), deficiencies in local production of vasoconstrictors and increased local production of substances that promote vasodilation. The commonest iatrogenic cause of heavy bleeding is the presence of a copper IUD.
A FBC with platelets (and sometimes serum ferritin and serum transferrin receptor saturation to assess iron status) is the only investigation needed before starting treatment, provided that clinical examination is normal. It should be remembered that iron deficiency is the commonest deficiency disease worldwide. Patients should be investigated if:
History of repeated or persistent irregular or IMB or of risk factors for endometrial carcinoma
Cervical screening test is abnormal
Pelvic examination is abnormal
Significant pelvic pain unresponsive to simple analgesia
No response to first-line treatment after 6 months
Additional investigations is typically to confirm or exclude the presence of endometrial malignancy. The main methods of investigation are ultrasound, endometrial biopsy, hysteroscopy and transvaginal ultrasound (with or without saline sonohysterography). Investigations for systemic causes of abnormal menstruation, such as partial coagulation screen for the disorder of haemostasis - a coagulopathy - of which mild von Willebrand disease is the commonest cause associated with HMB), are only indicated if a screening history for coagulopathies is suggestive or in young women. Thyroid disease is a rare cause of HMB, and investigation is only indicated if there are other features on examination or a previous history. Endometrial biopsy can be performed as an outpatient procedure either alone or in conjunction with hysteroscopy.
Hysteroscopy allows visualization of the uterine cavity using a 3-mm endoscope introduced through the cervix. It can be performed under GA or as an outpatient investigation using local anesthesia. Hysteroscopy with endometrial biopsy has largely replaced the blind dilatation and curettage. Transvaginal ultrasound is of value in distinguishing the structural lesions of the genital tract. In premenopausal women, ultrasound measured endometrial thickness will vary at different times of the menstrual cycle, but is usually possible to visualise structural lesions such as polyps in the endometrial cavity.