Uterine fibroids are benign (non-cancerous) abnormal growths of muscle cells and fibrous tissue within the uterus (womb). They are also called myomas or leiomyoma. Fibroids occur when a single muscle cell in the wall of the uterus multiplies and grows to form a non-cancerous tumour. It is a medical fact that most women will have fibroids during their lifetime. Usually, fibroid development occurs when a woman is in her 30s or 40s.
Fibroids can change the size and shape of the uterus and sometimes the cervix (lower part of the womb). Women usually have more than one fibroid tumour but single fibroids are possible. Whether or not fibroids may cause symptoms or require treatment depend on their number, location and size. This makes understanding the potential relationship between fibroids and infertility very important.
Where do fibroids grow?
Fibroids are usually found in or around the body of the uterus womb, but sometimes they grow in the cervix. These locations determine the type and possible effects on a woman.
• Outside or within the outer lining (sub serosal)
• On stalks, extending from the uterus (pedunculated)
• Within the uterine muscle (intramural)
• Between the uterine broad ligaments (submucosal)
Submucosal fibroid is the type of fibroids that reduce pregnancy rate, roughly by 50 per cent. In some cases, simply removing the submucosal fibroid solves infertility. Fibroids are quite common and in 20-80 per cent of women of childbearing age, developing even till about age 50 in some women.
Many women who have fibroids don't have any symptoms, and it is estimated that 30 per cent of women between the ages of 25 and 44 have various symptoms.
The most common symptoms include:
• Heavy menstrual bleeding
• Periods lasting more than a week
• Pelvic pressure or pain
• Frequent urination
• Difficulty emptying the bladder
• Constipation
• Backache or leg pains. On rare occasions a fibroid can cause acute pain when it outgrows its blood supply and begins to die.
Causes of fibroids
The exact causes of fibroids are not clearly known, but some of the following factors are suggested:
• Genetic changes. Many fibroids contain changes in genes that differ from those in normal uterine muscle cells.
• Hormones. Oestrogen and progesterone, two hormones that stimulate development of the uterine lining during each menstrual cycle in preparation for pregnancy, appear to promote the growth of fibroids. Fibroids contain more oestrogen and progesterone receptors than normal uterine muscle cells. Fibroids tend to shrink after menopause due to a decrease in hormone production.
• Substances that help the body maintain tissues, such as insulin-like growth factor.
• Extracellular matrix (ECM), the material that makes cells stick together, like mortar between bricks. ECM is increased in fibroids and makes them fibrous. ECM also stores growth factors and causes biologic changes in the cells themselves.
Uterine fibroids can develop from a stem cell in the smooth
