Heavy Menstrual Bleeding (“Menorrhagia”)

Menorrhagia is defined as heavy menstrual bleeding that is unacceptable to a woman. The usual volume of menstrual blood that is lost with each menstrual period is 30‐40mL. If a woman is losing more than 80mL per menstrual cycle it is likely that she will develop iron deficiency and anaemia. Common causes of heavy menstrual periods include:

• uterine fibroids
• advanced age, lack of ovulation
• pelvic infection
• adenomyosis
• endometriosis
• disturbances of blood coagulation

Sometimes no specific cause is discovered and this is called ‘dysfunctional uterine bleeding’. This ‘diagnosis of exclusion’ actually accounts for most cases of heavy menstrual bleeding.

Management of heavy menstrual bleeding starts with a consultation with a GP or gynaecologist. A physical examination will be performed and may include taking microbiological swabs and a Pap smear. You may be referred for blood tests to establish your iron status, haemoglobin, thyroid. A pelvic ultrasound may be ordered to look for fibroids and adenomyosis.

Fibroids

Fibroids are very common benign tumours of the uterine wall. They occur in more than 20% of women over the age of 35. They may sometimes be discovered during the course of pelvic ultrasounds for other indications such as pregnancy or pain. There are three main types of fibroids:

• Submucosal fibroids – these are fibroids close to the inside of the uterus and can distort the cavity of the uterus. These can be responsible for heavy periods. Some can be removed by a technique called endometrial resection which is performed under general anaesthesia.
• Intramural fibroids – these develop within the wall of the uterus and can also cause heavy periods. These are usually only detected on ultrasound examination.
• Subserosal fibroids - these distort the outer contour of the uterus and may press on adjacent organs such as the bladder or be easily palpable within the abdomen if very large.  These fibroids tend not to cause heavy periods and their removal has no impact on menstrual bleeding.

Adenomyosis

This condition is where the usual undulation of the lining of the womb (the endometrium) is exaggerated. These undulations of endometrium create a situation where there is a greater surface area from which to bleed and may also give rise to a sensation of congestion within the pelvis. Adenomyosis usually involves the back wall of the uterus and can lead to an overall increase in the size of the uterus. It is typically found in women in their 40’s.

Pelvic Infection

This is usually diagnosed by the performance of microbiological swabs particularly looking for chlamydia.

Bleeding Disorders

These are an uncommon cause of heavy menstrual bleeding, but may occur in women taking anticoagulant drugs such as Warfarin for the treatment or prevention of thrombosis.

Endometriosis

Endometriosis is a condition where some of the cells of lining of the womb (the endometrium) have made their way into the pelvic cavity by a process called retrograde menstruation. These cells then implant into the lining of the abdominal cavity and respond to hormones in a similar way to the endometrium of the uterus. These pockets of abnormally situated endometrial cells, referred to as endometriosis, bleed internally at a similar time as a period occurs.

Endometriosis sometimes has no symptoms associated with it and is discovered incidentally during the course of other surgical procedures. However, the presence of these deposits of endometriosis within the pelvis can result in increase in menstrual pain and flow, painful intercourse and pain on passing bowel motions when a woman has her menstrual period. Endometriosis can also be associated with reduced fertility. Physical examination may reveal tender areas within the pelvis and a reduction in the degree of mobility of the pelvic organs. Ultrasound examination may also show deposits of blood within either ovary. Ultimately the diagnosis is made by laparoscopy under general anaesthesia in hospital.