What are uterine fibroids?
Uterine fibroids, also known as uterine “leiomyomata” or “myomas”, are solid masses arising from the smooth muscle cells that form the uterine musculature, also known as the myometrium. They are present in 30-50% of women and, although they can occur in women of any ethnic background, uterine fibroids are more common in women of African-American descent. They are generally classified according to location:
- Submucosal fibroids: are located within the uterine cavity.
- Intramural fibroids: are located within the myometrium.
- Subserosal fibroids: arise from the myometrium and grow outside the uterine muscle.
Some fibroids have a combination of submucosal, intramural, and/or subserosal components as they can extend into more than one of the aforementioned areas.
How are uterine fibroids diagnosed?
- Signs and symptoms: Depending on the size, location, and number of uterine fibroids, some women may have excessively heavy periods as well as a greater duration of menstrual flow, significantly greater pelvic pain during periods and/or with intercourse, and/or pelvic pressure symptoms. Sometimes, if a uterine fibroid is pressing against the bladder or bowel, difficulty with urination or bowel movements may occur. Some fibroids are large enough to result in a subtle or obvious protrusion of the abdomen. Submucosal uterine fibroids, located within the uterine cavity, can decrease pregnancy rates and increase miscarriage rates due to changes in the surface of the uterine cavity where an embryo would implant.
- Exam and/or Pelvic Ultrasound: If a woman is experiencing any or all of the signs and symptoms listed above, a pelvic examination by her Ob/Gyn and/or pelvic ultrasound may diagnose uterine fibroids. Magnetic Resonance Imaging (MRI) gives the most accurate resolution to evaluate the size, location, and number of uterine fibroids in cases where more detailed imaging may be helpful.
- Hysterosalpingogram (HSG) or Saline Infusion Sonogram (SIS): Sometimes, uterine fibroids can be diagnosed when an HSG or SIS if performed during a fertility evaluation or a recurrent pregnancy loss evaluation.
Are uterine fibroids associated with subfertility?
- Submucosal fibroids: Submucosal uterine fibroids are thought to be associated with subfertility as they can adversely affect implantation, resulting in decreased pregnancy rates and increased pregnancy loss.
- Intramural fibroids: Although there is controversy in the medical literature regarding whether or not intramural fibroids affect fertility, there is data which shows that intramural fibroids greater than 4 centimeters in diameter are associated with subfertility.
- Subserosal fibroids: Subserosal uterine fibroids do not appear to be associated with subfertility.
Does the surgical removal of uterine fibroids (myomectomy) improve pregnancy rates?
- Submucosal fibroids: Removal of submucosal uterine fibroids is associated with higher pregnancy rates and lower risk of miscarriage/pregnancy loss. Submucosal uterine fibroids are removed by means of a day surgery called hysterscopic myomectomy which does not require any incisions as the fibroid can be accessed by dilation of the cervix so that a hysteroscope can be placed transcervically into the uterine cavity. Once the submucosal fibroid is indentified, it can be resected and removed in order to normalize the anatomy of the uterine cavity.
- Intramural fibroids: There is question as to whether or not removal of intramural fibroids improves pregnancy outcomes. If a couple’s fertility work-up is normal and basic fertility treatments have not resulted in pregnancy for a couple, then myomectomy can be considered. If a woman of reproductive age who desires future fertility has signs and symptoms from intramural uterine fibroids or if there is a rapid rate of growth of fibroids, myomectomy is recommended. Myomectomy for intramural fibroids is performed via the abdominal route. For women who have intramural fibroids <4 centimeters in diameter, that do not cause symptoms, as long as the uterine cavity is not compressed, it is common to proceed with fertility treatment without undergoing myomectomy.
- Subserosal fibroids: Removal of subserosal uterine fibroids does not improve fertility outcomes. If a woman of reproductive age who desires future fertility has signs and symptoms from subserosal uterine fibroids or if there is a rapid rate of growth of fibroids, myomectomy can be considered. Myomectomy for subserosal fibroids is performed via the abdominal route.