Causes of Fibroids
Fibroids RESOURCES
Genetic Predisposition
While the exact cause of uterine fibroids is still relatively poorly understood, research suggests that a genetic predisposition is a likely cause. Descendants of women who had fibroids, are more at risk of developing them. Another indicator of genetic correlation is based on the fact that women of African descent are statistically more at risk of developing fibroids.
Other Suspected fibroid Causes
There is also a correlation, although no confirmed direct causality between fibroids and:
· Obesity
· High blood pressure (Hypertension)
· Diabetes
What causes uterine fibroids to grow?
Fibroids grow through the multiplication of its cells. The increasing number of cells increases the mass and the size of fibroids. This growth is stimulated by the hormones produced by the ovaries during the menstrual cycle, most significantly oestrogen. This is why fibroids are extremely rare in young women before they start having periods and in women who have reached menopause.
It is important to notice that women with fibroids do not usually have increased levels of oestrogen in their blood and hormone test results are usually within normal range.
Cause of excessive growth of myomas
Fibroid tissue contains more receptors, or docking spots, for the hormone estrogen and progesterone. They sometimes are able to produce estrogen themselves. The excess of estrogen and sometimes progesterone are found to stimulate the growth of fibroids, hence why myomas are also referred to as hormone dependent tumours.
Researchers believed for a long time that fibroids follow linear growth during a woman’s reproductive years, however new evidence found that growth of myomas is not always linear, i.e, some fibroids grow very quickly while others remain small for long periods of time. Other studies showed that fibroids can go through periods of growth as well as regression during their life cycle.
Since fibroid growth depends on hormones, the risk of developing myomas diminishes considerably after menopause.
Do birth control pills cause fibroids?
No. In women that do not have fibroids, birth control pills can actually prevent the growth of new fibroids. In women where fibroids are already present, the use of pills with high doses of oestrogen can promote further growth of the nodules.
Low oestrogen and progesterone only pills (minipill) can be used to reduce excessive blood flow caused by fibroids.