Uterine fibroids are benign tumors that originate in the uterus. Although they are composed of the same smooth muscle fibers as the uterine wall (myometrium), they are much denser than normal myometrium, and thus protrude somewhat from the uterine wall, often causing pain and uterine bleeding.
We do not know exactly why women develop these tumors. Genetic abnormalities, abnormalities in the vascular (blood vessel) system, and tissue response to injury have all been suggested to play a role in the development of fibroids.
Family history is a key factor, since there is often a history of fibroids developing in women of the same family. Race also appears to play a role. Women of African descent are two to three times more likely to develop fibroids than women of other races. Women of African ancestry also develop fibroids at a younger age and may have symptoms from fibroids in their 20s, in contrast to Caucasian women with fibroids, in whom symptoms typically occur during the 30s and 40s. Pregnancy and taking oral contraceptives both decrease the likelihood that fibroids will develop. Other factors that researchers have associated with an increased risk of developing fibroids include having the first menstrual periodvprior to age 10, consumption of alcohol (particularly beer), uterine infections, and high blood pressure (hypertension).
Estrogen tends to stimulate the growth of fibroids in many cases. During the first trimester of pregnancy, about a third of fibroids will enlarge and then shrink after the birth. In general, fibroids tend to shrink after menopause, but postmenopausal hormone replacement therapy may cause symptoms to persist.
Overall, these tumors are fairly common and occur in about 70% to 80% of all women by the time they reach age 50. Most of the time, uterine fibroids do not cause symptoms or problems.
Abnormal uterine bleeding is the most common symptom of fibroids. If the tumors are near the uterine lining, or interfere with the blood flow to the lining, they can cause heavy periods, painful periods, prolonged periods or spotting between menses. Women with excessive bleeding due to fibroids may develop anemia. Uterine fibroids that are degenerating can sometimes cause severe, localized pain.
Fibroids can also cause a number of symptoms depending on their size, location within the uterus, and how close they are to adjacent pelvic organs. Large fibroids can cause:
- pelvic pain,
- pressure on the bladder with frequent or even obstructed urination, and
- pressure on the rectum with painful or difficult defecation.
While fibroids do not interfere with ovulation, some studies suggest that they may impair fertility and lead to poorer pregnancy outcomes. In particular, fibroids that deform the inner uterine cavity are most strongly associated with decreased fertility. Occasionally, fibroids are the cause of recurrent miscarriages. If they are not removed in these cases, the woman may not be able to sustain a pregnancy.
Do untreated uterine fibroids pose a risk?
For the most part, uterine fibroids that do not cause a problem for the woman can be left untreated. In some cases, even fibroids that are not causing symptoms require removal or at least close observation. Rapid growth is a reason to watch more carefully, since a rare cancerous form of fibroid (referred to as a leiomyosarcoma) is usually a fast-growing tumor, and it cannot be differentiated from a benign fibroid by ultrasound, MRI, or other imaging studies. However, this type of tumor occurs in less than 1% of uterine fibroids.
Another risk of leaving these tumors alone is that they sometimes grow to a size that eventually cause significant symptoms, thus requiring removal. If fibroids grow large enough, the surgery to remove them can become more difficult and risky.
What Can I do if I have fibroids causing Symptoms?
Fibroids can be treated in a variety of ways, depending on the size and symptoms involved. At NYC Surgical Associates, we most commonly treat fibroids with uterine artery embolization, a scarless, incisionless procedure done under local anesthesia and an advanced catheter system that blocks the blood supply to the fibroid, making it shrink in size.
Other options include surgical removal, as well as medical therapy.
A discussion with one of our specialists will help you to pick the ideal route of treatment for your individual case.