Fibroids

What are fibroids, and why do they cause excessive bleeding during menstrual cycles?

Fibroids are non-cancerous growths in, on, or within the walls of the uterus. About 20% of women of reproductive age, have them, and for most they cause very few problems.

Internal uterine fibroids can compress the endometrial lining (the inner lining of the uterus which grows during each menstrual cycle and is shed in menstrual blood). This compression is what causes excessive bleeding during, and occasionally between, menstrual periods. Even small internal fibroids can cause this symptom. If they are growing beneath the outside lining of the uterus, they can become enlarged and put uncomfortable pressure on the pelvis. They can potentially obstruct the ureters (the tubes that carry urine from kidney to the bladder) which is the most serious complication.

If they become very large these tumors can also obstruct the fallopian tubes or block implantation of the fertilized egg. Basically, the fibroids begin to take up room on the wall of the uterus, making implantation more difficult. In the case of pregnancy they can increase the risk of miscarriage or premature labor. Sometimes fibroids lead to strange implantation patterns, for instance the placenta may be forced to grow over the cervix (placenta previa) because there are few places remaining in the uterus for implantation.

The cause of uterine fibroids is unknown, but evidence suggests that their growth is tied to estrogen. Fibroids rarely cause problems for women before the age of 40, while they may have their origins in a woman's youth.

Fibroid tumors that cause no symptoms can be left untreated as long as they are monitored closely. However, large uterine fibroids usually require some form of treatment if they cause symptoms like bladder or pelvic pressure, excessive bleeding, pain, or infertility. The most drastic and thorough treatment for fibroids is a hysterectomy. If a woman is young, she may opt to have this procedure without removal of her ovaries. This way she will not go into menopause.

But there are several other treatment options available. Myomectomy, the surgical removal of only the fibroids is one. This procedure leaves the uterus intact, and is the treatment of choice for women who wish to maintain their fertility. Myomectomy does involve more blood loss than a total hysterectomy, as fibroids can have a rich blood supply. During a hysterectomy the blood supply to the uterus is tied off with removal of the organ, whereas the blood supply to a single fibroid is more difficult to locate and cannot be tied off. Myomectomy allows a woman to potentially retain fertility.

One of the most popular hormonal treatments for fibroids is a drug called Lupron. Lupron is an inhibitor to the secretion and release of the hormones that trigger the ovary to secrete estrogen and progesterone. It decreases these hormones to menopausal levels, and its side effects resemble many of the symptoms of menopause, i.e. heat flashes, mood swings, vaginal dryness, and bone loss.

Lupron can shrink fibroids to the point that surgery may be avoided and fertility preserved, but it cannot be taken if a woman is already pregnant. It also only works to shrink fibroids that are actively growing, leaving older fibroids in place. The effect is reversible upon discontinuation, which is obviously both good and bad. The fibroids will grow again upon discontinuation, but a woman will also be able to ovulate and thereby have the possibility of becoming pregnant.

The entire range of treatments, including surgical removal of just the fibroids, Lupron, or a combination of treatments should be discussed with a doctor.

REFERENCES
a listing of scientific articles and texts used.