Types And The Trouble They Can Cause.
What exactly is a fibroid tumor and what effects can one have during pregnancy? - Shana, Georgia
The expert answers
Uterine fibroids (leiomyomata uteri) are benign tumors that arise from the wall of the uterus (myometrium). It is estimated that about 50% of women will have fibroids by the time they reach 40. However, only about half of these women will develop any symptoms.
Symptoms vary depending upon the location of the fibroid, and obviously, its size plays an important role. Fibroids can occur in these locations:
Intramural: The fibroids are totally within the uterine wall. They can cause increasing pain with menstrual periods, and/or cause heavy or irregular vaginal bleeding. They can disrupt the normal blood supply to the lining of the uterus (endometrium), resulting in abnormal bleeding.
Submucosal: Partially within the uterine wall, but the rest impinges upon the uterine cavity (endometrium). These fibroids can cause bleeding for similar reasons as intramural fibroids. They can also play a role in infertility, however, this is not common. Less than 5% of women are infertile due to a fibroid. In these women, the fibroid can be surgically removed (myomectomy).
Subserosal: These are partially within the uterine wall, but the rest is outside of the uterus. These fibroids can cause pain and pressure because they can impinge on other pelvic and abdominal organs. Increasing urinary frequency or rectal pressure seem to be the most common. However, some women complain of bloating as well.
Cervical: These fibroids can occur within the cervix and can interfere with the normal dilation process of labor, resulting in a cesarean section. They can also contribute to significant pelvic pain or pain with intercourse (dyspareunia).
Ligamentous These fibroids can lie within the supportive "ligaments" of the uterus. Typically, these fibroids cause pelvic pressure or pain.
Any fibroid can cause the onset of acute pain. Some fibroids grow so rapidly that they outgrow their own blood supply and infarct. These can cause very intense pain.
Fibroids are very sensitive to estrogen levels. After menopause, fibroids tend to shrink and cause less symptoms. During pregnancy, the elevated levels of estrogen and progesterone could potentially cause a fibroid to grow. Although bleeding is not a common problem with fibroids in pregnancy, pain and pressure are more likely.
A submucosal fibroid could potentially block the baby from turning head down. Most obstetricians tend to perform cesarean sections for breech babies. If the placenta implants over a fibroid, then the blood supply to the baby theoretically could be decreased, resulting in a smaller infant.
As previously mentioned, cervical fibroids can potentially block adequate dilation. However, sometimes the fibroid becomes so soft during pregnancy that they can "mold" and allow dilation to occur and the baby to pass through the birth canal without problems.
For the most part, fibroids in pregnancy are an incidental finding (e.g. they are diagnosed during an ultrasound). Their location and growth need to be closely monitored, but most women delivery without any complication associated with the fibroid.