Fibroids or leiomyomas are benign tumors of the uterus. These tumors are very common and approximately one in five women over the age of 30 years has a fibroid. Uterine fibroids tend to be more frequent in African American women and less frequent in women from other ethnic groups (i.e. Asian).
Often fibroids cause no symptoms and are found during a routine gynecological examination such as an annual exam when an enlarged or irregularly shaped uterus is noted. It is confirmed by ultrasound. Sometimes fibroids are found during an infertility evaluation when tests such as a pelvic ultrasound, sonohystogram (SHG) or hysterosalpingogram (HSG) are ordered.
Fibroids are classified according to their location in three types:
1) subserosal - when the fibroid grows on the outside of the uterus
2) intramural - when the fibroid grows within the muscular wall of the uterus
3) submucosal or intracavitary - when the fibroid grows just under the lining of the uterine cavity (mucosa) or it occupies the inside of the uterine cavity. Submucosal or intracavitary fibroids can change the shape of the uterine cavity.
Large intramural fibroids may alter the blood flow to the uterine lining and may also alter the shape of the uterine cavity. Subserosal fibroids usually don't alter the shape of the uterine cavity, but when large can cause discomfort.
Most fibroids are usually small, asymptomatic, and don't require treatment. These benign tumors only need close gynecological observation to document changes in size or the early onset of symptoms.
Common symptoms associated with fibroids are back pain, abdominal pressure or discomfort, urinary frequency, rectal pressure or discomfort, and periods that can be painful, heavy and prolonged.
Fibroids are associated with infertility in 5 to 10% of cases. Nevertheless, when all other causes of infertility are excluded fibroids may account for only 2 to 3% of infertility cases. Fibroids may cause reduced fertility or infertility by:
1. Creating an abnormal uterine cavity. An enlarged or elongated cavity could interfere with the sperm transport, and a cavity with an abnormal contour could prevent normal implantation.
2. Fibroids can result in a markedly distorted uterus and cervix. The distortion could result in decreased access to the cervix by the ejaculated sperm preventing its effective transport to the uterus.
3. Fibroids may block or severely distort the fallopian tube as it inserts into the uterus. Sperm may not be able to reach the fallopian tubes (and the ovulated egg) and likewise the fertilized egg may not be able to reach the uterus.
When infertile women present with uterine fibroids every effort should be made to exclude other possible causes of infertility. A standard infertility evaluation should take place and an assessment of the uterine cavity should be performed by hysterosalpingogram (HSG) or "fluid" ultrasound (sonohystogram). Only then should a decision be made regarding the management of the fibroids.
Most uterine fibroids don't need to be removed except in select cases. The medical literature suggests that removal can be beneficial when the uterine cavity is distorted by the fibroids. In addition, some reports suggest their removal may also be indicated when they are about 2 inches or more in diameter and are located within the wall of the uterus (intramural). Otherwise, expectant (watchful) management is recommended when the uterine cavity is normal, the fibroids are small, or when they are located on the surface of the uterus.
Fibroids are removed in a surgical procedure called a "myomectomy". Three types of myomectomy can be performed: abdominal myomectomy, laparoscopic myomectomy, and hysteroscopic myomectomy. Read more about Myomectomy.
There are other options for the treatment of uterine fibroids, but these alternatives are not recommended for women who desire fertility. Some of these options are:
1. Uterine artery embolization (UAE) - results in the obstruction of blood flow to the fibroids, which then causes them to shrink. This procedure is quite successful in reducing tumor size and decreasing symptoms. Pregnancies have been reported after UAE but the safety of this procedure in women who want to get pregnant has not been established.
2. Medical therapies with agents such as GnRH agonists, progestational agents, and RU486 (mifepristone). These medications can decrease uterine size and symptoms, but once the treatment is discontinued the fibroids can grow back to their initial size. The use of these medications is not effective in promoting fertility and is not recommended when women are attempting pregnancy.
3. New techniques are being developed for the treatment of uterine fibroids. One of these new techniques is laparoscopic myolysis* in which a needle is used to apply electric current directly to fibroids. The goal is to disrupt the blood flow of fibroids and cause them to shrink over time. A similar laparoscopic procedure uses super cooled cryoprobes to destroy the fibroids. Another technique uses magnetic resonance imaging (MRI) to target high intensity ultrasound waves to destroy the fibroids. Again, the safety of these procedures in women who want to get pregnant has not been established.