By Richard Taavon, MD, FACOG of Wendover OBGYN
Uterine leiomyomas (myomas), or fibroid tumors, are the most common pelvic tumors in women and the leading indication for hysterectomy and a major health concern in the United States. The proportion of women in which fibroid tumors develop is unknown but a hysterectomy study published in 1990 found myomas in 77 percent of uterine specimens.
There are many risk factors for fibroids which include race, hormonal contraception, weight, and diet. Fibroids are more common in black women than in white women. The reason for this is unknown. In addition, fibroids appear at younger ages in the black female population and tend to grow consistently until later ages. Early menarche (onset of menstruation) appears to be associated with an increased risk of fibroids while increasing parity (pregnancies extending beyond 20 weeks) seems to decrease the risk of myoma formation. Hormonal contraceptives (birth control pills) do not appear to affect fibroid growth while progestin only contraceptives (IUD, depo medroxyprogesterone) might protect against fi broid formation. Most studies seem to suggest a relationship between myoma growth and increasing body mass index (obesity).
The diagnosis of fibroids is usually based on the finding of an enlarged irregularly shaped uterus on physical exam and
is usually confirmed by ultrasound. Symptoms attributable to fibroids can be classified by their impact on bleeding, pain,
and fertility. Heavy and/or prolonged bleeding is the most common fibroid symptom. Dysmenorrhea (painful menses)
and dyspareunia (painful intercourse) are also commonly reported by many women with fibroids. Leiomyomas can distort
the cavity of the uterus in some instances causing difficulty in conceiving a pregnancy and an increased rate of miscarriage.
The natural growth/shrinkage of fi broids has never been systematically studied. Most studies have shown that myoma growth rates were not influenced by fibroid size, fibroid location, obesity, or number of pregnancies. Many experts would agree that
1. Spontaneous shrinkage of fi broids occurs;
2. Fibroids from the same woman grow at different rates; and
3. Fibroid size does not predict growth rate.
At the time of menopause, the relief of bleeding related to fibroids should occur. As estrogen levels decrease, most,
but not all, women will experience shrinkage of fibroids. The prevalence of fibroids in postmenopausal women
is approximately one-tenth of that of premenopausal women. Therefore, myomas are a potential but uncommon
cause of bleeding in menopausal women. The diagnosis of sarcoma (aggressive rare cancerous tumor) should be
considered in postmenopausal women who are thought to have myomas causing symptoms. The incidence of
sarcomas is higher in this group is higher, but is still very small. Use of postmenopausal hormone therapy in women
with leiomyomas may cause continued symptoms after menopause. These risks appear to depend on the location of
the fibroid tumor and possibly on the type/dose of estrogen preparation.