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Pregnancy

Fibroids (Leiomyomata)

  1. What are fibroid tumors of the uterus/cervix and what causes them?
  2. What are the most common symptoms of fibroids?
  3. How do fibroids affect pregnancy?
  4. Can fibroids cause infertility?
  5. Can fibroids affect the size of my uterus?
  6. What is Uterine Fibroid Embolization (UFE)?
  7. Can phytoestrogens help prevent fibroids?
  8. What are vaginal tumors?
  9. After menopause, what are the chances my fibroids will shrink?
  10. How are fibroids treated?
  11. What is the relationship between the CA 125 Test and uterine fibroids?

What are fibroid tumors of the uterus/cervix and what causes them?

A fibroid tumor is a benign growth of the uterus/cervix, which continues to grow until a "knot" is formed. The reason that fibroids occur is not completely known. The uterus is made of muscle and this tissue can grow. This usually happens in multiple locations in the uterus and causes multiple fibroids.

What are the most common symptoms of fibroids?

Most women who have fibroids have no symptoms and don't need any therapy. Others may notice a greater than normal amount of menstrual flow, more menstrual pain or cramping, and/or blood clots. In addition, a fibroid uterus can cause irregular bleeding in between normal periods. Heavy menstrual bleeding from fibroids can contribute to iron deficiency anemia. Your gynecologist will want to make sure there are no other causes of anemia.

How do fibroids affect pregnancy?

Fibroids tend to grow very slowly. The location or size of a fibroid might make it more difficult to carry a baby to term. The extra hormones a woman's body makes during pregnancy can cause a fibroid to grow and take up space in the uterus that the baby needs. The baby could end up being born prematurely (early) or be miscarried. Fibroids near the cervix may not allow the baby to pass through the birth canal and require a Cesarean section for delivery.

Fibroids are VERY common.

Nearly one quarter to half of all women have them by the age of 50.

Fibroids do not necessarily HAVE to be removed.

Few women ever experience symptoms requiring any intervention, such as fibroid removal.

The uterus can enlarge slightly after having had children. This is normal, and requires no follow-up. Fibroids (leiomyomata) are benign growths of the muscle of the uterus, which is the most common reason for uterine enlargement in women. If they remain stable and aren't causing symptoms, they rarely require any attention. A slightly enlarged uterus requires no further testing other than routine yearly exams to determine its stability.

Estrogen does contribute to the growth of fibroids, but the levels used in hormone replacement therapy (HRT) are unlikely to cause growth of existing fibroids. The size of fibroids can be documented by physical (pelvic) exam or ultrasound.

Can fibroids cause infertility?

The case of fibroids and infertility is controversial. A hysterosalpingogram may show that both tubes are open and that the fibroid is not interfering with the ability of sperm and egg to interact. Another possibility is a fibroid interfering with the implantation of the fertilized egg. This depends on the location, size and degree to which the fibroid is distorting the cavity. In cases of unexplained infertility (infertility of greater than 1 year with no known cause) removal of the fibroid has been proposed, but the literature is unclear as to the benefits.

If ALL causes have been ruled out, then removal of the fibroid may be appropriate. However, the risks of scarring, which would cause more problems with infertility does exist. Therefore, surgery is a last resort. Other factors may be a bigger reason for difficulties with infertility.

Can fibroids affect the size of my uterus?

Fibroids, benign growths of the muscle of the uterus, are the most common reason for uterine enlargement in women. It is estimated that about 30-50% of women have these. If they remain stable and aren't causing symptoms, they rarely require therapy.

What is Uterine Fibroid Embolization (UFE)?

Uterine Fibroid Embolization (UFE) is an experimental procedure that is being researched. A substance is injected into the vessels supplying the uterus. The vessels are blocked thereby decreasing the flow of blood to the uterus and reducing the size of the fibroids.

A review of the medical literature reveals two published reports of UFE. They state that there is an approximately 40% reduction in size with a majority of patients reporting satisfactory results. They admit that the studies have low numbers of patients, no long-term follow-up and lack of a comparison group. The cost and particular method of anesthesia used is not available and likely varies.

The UCLA Medical Group is one of the more prominent centers doing Uterine Fibroid Embolization (UFE). Their web site provides a lot of information on UFE, but realize it is not an unbiased source.

Can phytoestrogens help prevent fibroids?

Phytoestrogens are naturally occurring substances that have some of the properties of estrogen. Soybeans are rich in phytoestrogens. In addition to their estrogenic properties, some of these chemicals also appear to have other important properties that may be beneficial. Some scientists believe that:

A search of the medical literature has not turned up any studies on the interaction of soybeans and fibroids. Additional investigation is needed in this area. In the future, it is possible that phytochemicals will be found to have a beneficial role in the management of common gynecologic problem.

What are vaginal tumors?

Vaginal tumors are masses in the vagina. They can arise from any of the tissues lining the vagina: skin, muscle or glands. Also, masses from the uterus can protrude into the vagina. A fibroid tumor from the uterus is such an example. It can arise from the cervix or higher up in the uterus and protrude from the cervix. All vaginal tumors must be evaluated to rule out cancer.

After menopause, what are the chances my fibroids will shrink?

Fibroids are much less common after menopause. The most likely reason for bleeding to cease is that without estrogen, the lining of the uterus (the area that sheds every month) doesn't grow and therefore no bleeding occurs. Even if fibroids do not shrink (and they often do) after menopause, they should stop growing.

How are fibroids treated?

Lupron is a synthetic form of a natural hormone (Gn-RH). Gn-RH stimulates the production of testosterone in men and estrogens in women. However, when synthetic Gn-RH is given, it actually stops natural production of hormones. As a result, in women who are premenopausal, menstruation will stop. Essentially, it induces temporary menopause. That is the reason why it works for endometriosis and fibroids. It also explains why it works for advanced prostatic cancer; it stops hormone production so tumor growth stops also. This is only temporary therapy and is rarely continued for more than 6 months. After the Lupron is stopped, the fibroids usually grow back.

Progestins such as Depo-Provera or Provera have been used to treat the symptoms of fibroids. Use of these medications can decrease bleeding and cramping associated with fibroids. It may also help slow the growth of fibroids.

Fibroids can be treated surgically with either a hysterectomy (removal of the uterus) or myomectomy (removal of the fibroids). Women who have a myomectomy lose more blood than with hysterectomy and usually require surgery again because the fibroids return. That is why myomectomy is best reserved for women who wish to maintain their fertility or have certain medical conditions. Bleeding from fibroids can cause anemia and should not go unchecked.

What is the relationship between the CA 125 Test and uterine fibroids?

Uterine fibroids can produce an elevated CA 125 level, which has nothing to do with the ovary or ovarian cancer. CA 125 can also be normal in women with fibroids.

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Last Reviewed: May 08, 2000

Arthur T Ollendorff, MD Arthur T Ollendorff, MD
Associate Professor of Obstetrics and Gynecology
College of Medicine
University of Cincinnati