Which Women Develop Fibroids and the Symptoms

The two most common symptoms associated with fibroids are heavy menstrual periods (termed menorrhagia) and pelvic pressure or discomfort. (There is a movement away from using these older words, such as menorrhagia, to make the terminology more understandable.) Menorrhagia involves periods that are either long or heavy or both. Typical menstrual periods last 4 to 5 days, so, generally, any woman who has 7 or more days of menstrual bleeding is considered to have menorrhagia. Some women have relatively short periods (in the range of 3 to 4 days), but their periods are excessively heavy.

There is no good classification system for the heaviness of periods. When I was a student, one of the senior doctors said that whenever he got a call from a patient complaining of heavy bleeding, he would ask whether the bleeding was so heavy that blood would fill up her shoes if she were standing without a pad. If she replied that it was, he would ask her to come in immediately. Although an exchange like this would be considered patronizing today, it does illustrate the difficulty of describing excessive bleeding. There are other ways to get an assessment of heavy menstrual bleeding, but there are no good studies looking at the reliability of these measures.

The following commonly occur in women with fibroids and heavy menstrual bleeding: 

  • Needing to change a pad or a tampon more frequently than every two hours.
  • Needing to use double sanitary protection (a pad and a tampon, or two pads or two tampons) frequently. 
  • Wearing adult diapers for menstrual control. 
  • Flooding is the common term for loss of control of menstrual flow.Even with the maximal use of pads and/or tampons, when flooding occurs, women may still have menstrual accidents that stain their clothes.
  • With heavy flow, women also typically get up at night to change sanitary protection or frequently soil their bedclothes. 
  • Many women deal with the heavy menstrual flow by changing their work or social schedule. Any change in your schedule because of your menstrual period is likely to mean that you have significant menstrual flow.

It is also important to check whether a woman with fibroids has anemia (a low red blood cell count). Several different tests can be ordered, including a hematocrit, a hemoglobin, or a complete blood count (CBC). An old notion stipulates that if a woman is not anemic, she cannot have significant menstrual bleeding. But many women are able to maintain normal blood counts with iron, vitamins, and diet despite substantial blood loss. Conversely, some women don’t feel that they are having heavy bleeding, but they develop significant anemia from their periods.

The second common symptom associated with fibroids is pelvic pressure or discomfort. This typically is not sharp or disabling pain but rather discomfort based on the size of the uterus and the pressure the uterus causes on adjacent organs as illustrated in below: 

pelvic organs picture

The uterus is in the pelvis and thus is normally not felt by pushing on the abdomen. This is why a pelvic exam is performed as a part of gynecologic care. The bladder is in front of the uterus and rests on the lower part of the uterus and upper cervix. The bowel (rectum) is behind the uterus. When the body is viewed in cross section, the bladder is in front of the uterus, which in turn is in front of the rectum. Each of these important pelvic structures also leads to an opening on the perineum: the bladder terminates in the urethra, the uterus in the vagina, and the rectum in the anus. When looking at the perineum, as is done when a woman has a pelvic exam and is lying on her back, these openings go from top to bottom, so that the urethra is most superior, the vagina is below that, and the anus is the bottom most opening. The ureters carry urine from the kidneys (located in the back above the belly button, termed the flank) to the bladder and thus pass to either side of the uterus.

The pain from fibroids is similar to the discomfort pregnant women have because fibroids enlarge the uterus to sizes commonly seen in pregnancy. Just like pregnant women, women with fibroids can have urinary frequency, difficulty with bowel movements or constipation, difficulty emptying their bladder completely, back pain, abdominal distention, sciatica (pain radiating from the buttocks down the back of the leg), and bloating.

The fibroids can become quite large before the woman recognizes these problems. The slow development of the fibroids over time probably accounts for this delay in perception. Pregnant women at 5 months know that their symptoms are different from before they were pregnant; however, a woman with a 5-month-sized fibroid uterus may have had it steadily grow over 5 to 10 years, and therefore she mistakenly attributes the changes to other processes, such as aging.

Sudden or severe pain can occasionally occur with fibroids. These symptoms typically occur under two circumstances. The first is when the fibroid grows faster than its blood supply and the center of the fibroid dies or degenerates. This can happen to any type of fibroid. The second circumstance for acute pain occurs with a pedunculated fibroid (a fibroid on a stalk). If the fibroid twists on its stalk, it can cut off blood supply and cause sudden pain. However, given the perception that sharp, severe pain is uncommon with fibroids, before concluding that fibroids are a source of acute pain, other causes should be investigated, including an ovarian cyst or endometriosis. Some information coming from studies of women undergoing uterine artery embolization as a treatment for fibroids suggests that pain with fibroids may be more common than previously thought.

Reproductive dysfunction, including infertility, miscarriage, and pregnancy complications, can also be associated with fibroids. However, most women with fibroids get pregnant without difficulty and have uncomplicated pregnancies and deliveries. Again, before attributing reproductive difficulties to a fibroid, a thorough investigation of the woman and her partner should take place to exclude other, more common causes. Difficulty getting pregnant (infertility) or problems with early miscarriages are most commonly seen with fibroids that distort the endometrial cavity (submucosal fibroids).Luckily, these fibroids are the ones that are most easily treated in a minimally invasive fashion with a hysteroscope.

Fibroids can sometimes cause problems during pregnancy. These complications of pregnancy are more likely with larger fibroids and with fibroids that are located directly beneath the placenta. The pregnancy complications that have been associated with fibroids include the following:

  • Bleeding in the first trimester
  • Increased risk of cesarean section
  • Increased risk of preterm labor
  • Increased risk of placental abruption

We don’t precisely know why the size of the fibroid and the location of the placenta in relation to the fibroid are critical to pregnancy complications. I like to use the analogy of planting a tree in soil that has a large rock beneath it. While initially it may be fine, as the roots get established, the tree will not flourish. The placenta grows into the uterine wall, and if it has a large mass at its base, its growth may be impeded, a situation similar to what happens with the tree.

A second issue related to pregnancy complications may be that the microscopic composition of the endometrium (lining of the uterus) and the molecules produced in the endometrium of women with uterine fibroids may be abnormal. The process of a pregnancy implanting in the uterus involves a “molecular dialogue” between the embryo and the endometrium. The embryo looks for and responds to specific signals from the uterus. Either the fibroid may misdirect the embryo to a less favorable place for implantation, or the endometrium may be lacking in a specific component required for implantation or pregnancy success.

A final problem with fibroids (not related to pregnancy) is that, rarely, fibroids can become so large that they place pressure on the ureters, which carry urine from the kidneys to the bladder. Sometimes if this pressure is severe and there is damage to the kidneys (moderate or severe hydronephrosis), even fibroids that are not causing symptoms need to be removed.

How Common Are Uterine Fibroids?

Studies show that up to 80 percent of women have fibroids in their uterus.3* This figure comes from microscopic study of uteruses (also termed uteri) removed at the time of surgery and uteruses removed from women who died of nongynecologic causes. Thus, it is likely that most, if not all, women have some microscopic fibroids in their uterus.

The percentage of women with clinically significant uterine fibroids (ones large enough to be felt on pelvic exams or visualized on ultrasound) is commonly reported to be approximately 25 percent. Calculating 25 percent of women between the ages of 19 and 64 from recent census figures for the U.S. population would mean that 23 million women might be estimated to have fibroids. However, this percentage varies with how thoroughly women are evaluated to Thus, studies that report only fibroids felt on pelvic exam will underestimate fibroids compared with studies that use ultrasound. It is clear, however, that black women have an increased risk of having fibroids (termed prevalence). They also appear to develop fibroids at three times the rate of Caucasian women (termed incidence).

There is some evidence that black women with fibroids also develop more severe disease and do so at an earlier age. A study has estimated that up to 80 percent of African American women in the United States will develop ultrasound-detectable fibroids. Although large-scale studies have not been conducted in Africa, it appears that African women have a similar risk of fibroids. The studies that have been done to date also suggest that this increased prevalence and incidence are not due to other confounding factors (factors that would vary between African American and Caucasian women and would account for this difference, such as age at first pregnancy, height, and weight).

Factors That Can Influence a Woman’s Chance of Developing Uterine Fibroids

Race can affect your risk. As discussed in the previous section, being African American appears to lead to an increase in risk of fibroids. Hispanic and Asian women appear to have the same risk as Caucasian women. However, the number of Hispanic and Asian women in the studies done to date has been small. It is also not clear whether there is a difference between women in Africa and African American women in terms of fibroid risk. Most of the studies to date have been done in the United States or Europe, but it does appear that women in Africa also have significant problems with fibroids.

Having close relatives with fibroids appears to increase risk. This factor is called familial clustering, and it suggests that there may be a genetic reason for developing fibroids. Delivering a baby leads to a decreased risk of uterine fibroids.

Having delivered a baby is termed parity.We do not understand why pregnancy decreases the risk of fibroid formation, but some scientists cite the remodeling of the uterus that takes place following pregnan-cy as possibly clearing newly formed fibroids.

Some studies suggest that taking oral contraceptive pills may decrease the risk of fibroid formation. Many textbooks continue to say that women with fibroids should not take birth control pills because of the concern that the fibroids might grow rapidly. Although this can happen, many fibroids do not grow over time. The difference in findings is likely explained by the fact that, once established, the fibroids can respond to the hormones in the pills; on the other hand, the steady state of hormones in the pill may prevent cells from forming fibroids or fibroids from starting the growth process. The timing of beginning the birth control pill may be critical. In the large Nurses’ Health Study most women on pills had a decreased risk of fibroids, but women starting pills between the ages of 13 and 16 actually had an increased risk.

Smoking also decreases the risk of fibroids, possibly because of differences in estrogen levels in smokers. Nonetheless, the benefit from decreased fibroids does not outweigh the substantial risks of smoking.

Diet also appears to influence fibroid risk. Women with diets rich in fruits and vegetables have a decreased risk of fibroids, and women with diets rich in red meats have an increased risk.

Consumption of alcohol, especially beer, also increases the risk of fibroids.

Caffeine has not been shown to affect risk.

Use of a progestin-only contraceptive such as Depo-Provera appears to decrease the risk of having fibroids. This has been best documented in African American women.

Body mass index (BMI; the relationship between weight and height) and weight appear to influence risk as well, with heavier women generally having greater risk. However, no one has documented definitely that losing weight helps with fibroids, although weight loss has many health benefits.