Uterine fibroids, also known as leiomyomas or fibroid tumors, are noncancerous growths found in the uterus. According to MayoClinic.com, up to 75 percent of women have fibroid tumors during their childbearing years, often without realizing they have them, as the growths are frequently asymptomatic. It’s not clear what causes uterine fibroids, though some risk factors have been identified. Researchers are focusing on hormones and genetics as possible underlying causes.
Hormones
The American College of Obstetricians and Gynecologists’ online guide to uterine fibroids notes that female hormones estrogen and progesterone are strongly linked to fibroid tumor growth. These hormones are more prominent during childbearing years, when fibroids are most commonly discovered, and the leiomyomas tend to shrink during menopause, when estrogen levels decrease sharply. The use of birth control pills containing estrogen is associated with fibroid growth. So is pregnancy, when female hormone levels are elevated. MayoClinic.com adds that other chemical substances present in the body, such as growth factors, may also influence the development of uterine fibroids.
Genetics
The number and size of fibroids and type and degree of seriousness of symptoms varies widely among women. This may be due to genetic factors, as the development of uterine fibroids tends to run in families, according to information posted on the National Women's Health Information Center website. Researchers have also found evidence that these growths may develop from “misplaced cells present in the body before birth,” according to the ACOG website.
Risk Factors
Though no specific cause for uterine fibroids has been pinpointed, a number of risk factors have been identified with the growth of these tumors. According to the National Uterine Fibroid Foundation, these include race, age, weight and foods.
Fibroids are more frequently found in African-American women, while the incidence is decreased in Asian women. Not only that, but African-American women begin to develop uterine fibroids at a younger age, and they are more likely to experience negative symptoms compared to other women.
Fibroids are most generally discovered in women between ages 35 and 50, which is also when they are most likely to be symptomatic.
Women who are obese are more likely to have uterine fibroids, though the relationship between these is very unclear.
High intake of beef and ham has also been associated with fibroid development.
