Fibroids, In A Variety of Types And Sizes
Uterine fibroids are common benign tumors which grow out of the muscle tissue of the uterus, either singly or in multiples. They are not uncommon, with estimates suggesting anywhere from 20 to 50 percent of women having at least one type of fibroid. Fibroids may grow in the uterine cavity (submucous fibroids); they can be located in the wall of the uterus (mural) or, they may protrude outside of the uterine wall, but remain attached to the uterus (subserous). The type that causes the most serious complications is submucous fibroids which are linked to infertility, miscarriage and other problems.
In most cases, fibroids are not problematic and in other cases severe pelvic pain, unusually heavy menstrual periods or problems with fertility are experienced. In some women, fibroids are the cause of recurrent miscarriages.
Fibroids Are Associated With Miscarriage
Research has found that fibroids are the exclusive culprit in infertility or miscarriages in about 5 percent of the women who experience these situations. Doctors believe both infertility and miscarriage due to fibroids are because of the type of tumor and the placement of the tumor on or in the uterus. A study done at the University of North Carolina at Chapel Hill was lead by principal investigator Dr. Katherine Hartmann who is also the assistant professor of obstetrics and gynecology as well as epidemiology in UNC’s schools of medicine and public health.
This study showed that small uterine fibroids are associated with an increased risk of miscarriage. Dr. Hartmann says, “No studies have prospectively investigated these risks in a large cohort of women early in pregnancy where presence of fibroids was uniformly assessed using ultrasound imaging. This is the first large-scale prospective study to do that.” She also said, “Fibroids are very common, as are these potentially devastating pregnancy outcomes. But research evidence to inform clinical care is meager.”
Past Studies Were Flawed
In the past, ultrasound studies of uterine fibroids did not present accurate information because included in the databases was uterine fibroids that were of concern to doctors. The problem was that these fibroids were at least three centimeters in size which meant that small, less noticeable fibroids were not noted.
“So the studies are flawed by inadequate assessment of the classification of who has fibroids and who does not,” Dr. Hartmann says. “In our pilot study of 1,600 women, we discovered that the majority of those who have fibroids never have been told that they did.”
In the study, 176 women were diagnosed with fibroids. The results of the pilot study indicate that women with fibroids have an increased risk of 55 percent for miscarriage. It is also noted that the smaller fibroids have a greater impact upon miscarriage than the larger ones and furthermore, it appears that there is a close association between the presence of fibroids and miscarriage in early pregnancy.