Why Do Fibroids Cause Abnormal Uterine Bleeding?

More than any other fibroid-related complaint, abnormal uterine bleeding is the reason most women visit their doctors. Abnormal uterine bleeding is also the under-lying reason many women with fibroid tumors choose to have hysterectomies. Excessive bleeding may be linked to one of the least common types of fibroids, called a submucous or submucosal fibroid. Regardless of the term used, the type of growth is the same. This kind of fibroid tumor develops directly beneath the surface of the endometrium.

Even though submucosal fibroids may not be as common as their cousin fibroids that grow in other parts of the uterus, they are the cause of the most trouble. Submucosal fibroids not only are associated with abnormal uterine bleeding, they have also been linked to miscarriages and complications of pregnancy. If you are anemic, have experienced several months of pro-longed menstrual bleeding, and are known to have fibroids, a submucosal fibroid may be the type of fibroid (or fibroids) you have.

Of course, your physician will extensively evaluate you before arriving at this diagnosis because there are other causes of uterine bleeding. When your physician examines you for the possible presence of a submucosal fibroid, she or he also will want to rule out any other possible cause of abnormal bleeding, such as ovarian or colorectal cancer. In addition to a manual pelvic examination, your doctor will want a  biopsy of your endometrial tissue.

A biopsy removes tissue so that the cells can be viewed under a microscope. Imaging tests, such as a sonogram, also help your doctor reach a diagnosis. Unlike fibroids that develop in other positions on or inside the uterus, submucosal fibroids tend to have a substantial number of blood vessels on their surfaces that can bleed. They also tend to prevent the uterine muscle from properly contracting because they distort the shape and function of the organ. Another note-worthy feature of submucosal fibroids is their ability to grow large enough to obstruct the fallopian tubes, thus preventing passage of an egg in its journey to the uterus.

But the story does not end there. These fibroids distort the uterine lining as they grow, causing menstrual irregularities. They may even become pedunculated and project into the cervix or even the vagina. As this growth moves about, because it is on a stalk and can twist and turn, it becomes a source of pain as well as abnormal bleeding. It is common for doctors to diagnose and remove submucosal fibroids that are the size of tennis balls. Submucosal fibroids present many dilemmas for women and their doctors. They can be removed individually in a surgery called a myomectomy, or the fibroid and the uterus can be removed together in a hysterectomy. Hysterectomies have been recommended when women have multiple submucosal fibroids or excessive uterine bleeding.