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