Uterine fibroids are common, non-cancerous growths that develop within the uterus. While many women experience no symptoms, these growths can impact fertility. This article explores how fibroids affect fertility, their diagnosis, and treatment options.
What Are Uterine Fibroids?
Uterine fibroids, also known as leiomyomas or myomas, are benign (non-cancerous) growths originating from the smooth muscle cells and fibrous connective tissue of the uterus. They are common, affecting up to 70-80% of women by age 50. Fibroids vary widely in size, from tiny to very large, and a woman may have one or many.
Their location within the uterus is a key factor in determining symptoms and impact. Submucosal fibroids grow into the uterine cavity, just beneath the inner lining. Intramural fibroids are found within the muscular wall of the uterus and are the most common type. Subserosal fibroids develop on the outer surface. While many fibroids cause no symptoms, others can lead to heavy menstrual bleeding, pelvic pain or pressure, and frequent urination.
How Fibroids Can Affect Fertility
Uterine fibroids can interfere with conception or carrying a pregnancy to term, depending on their size, number, and location. While common, fibroids account for about 3% of infertility cases.
Submucosal fibroids, which protrude into the uterine cavity, are often the most problematic for fertility. They can distort the uterine cavity, making it less receptive for embryo implantation. This distortion can also interfere with sperm movement and placental development, potentially leading to lower implantation and live birth rates, and an increased risk of miscarriage.
Fibroids located near or within the cornua of the uterus, where the fallopian tubes enter, can physically block the fallopian tubes. This blockage prevents sperm from reaching the egg or a fertilized egg from traveling to the uterus. Even large intramural fibroids can distort the uterine cavity, impacting fertility.
Fibroids can also affect fertility by altering blood flow to the uterus and its lining. Large intramural fibroids or multiple fibroids may reduce blood supply to the uterine lining, making it less receptive to embryo implantation. This impacts the embryo’s ability to embed and receive nutrients. The presence of fibroids can also create an inflammatory environment within the uterus, disrupting the uterine lining’s receptivity and affecting implantation success.
Diagnosing Fibroids and Infertility
Diagnosing uterine fibroids, especially when infertility is a concern, involves several steps. A healthcare provider begins with a pelvic exam, which may reveal an enlarged uterus, though smaller fibroids might not be detected.
Ultrasound is the primary imaging method, using sound waves to create images of the pelvic organs. Both transabdominal and transvaginal ultrasounds visualize the uterus, ovaries, and fallopian tubes. For detailed assessment, Magnetic Resonance Imaging (MRI) of the pelvis maps the size, number, and location of fibroids, useful for surgical planning.
Hysterosalpingography (HSG) is an X-ray procedure using a special dye to visualize the uterine cavity and fallopian tubes. This test can reveal distortions caused by submucosal fibroids and check for fallopian tube blockages. Hysteroscopy allows direct visualization of the uterine cavity; a thin scope with a camera is inserted through the cervix, enabling doctors to see and sometimes remove submucosal fibroids. Laparoscopy is a minimally invasive surgical procedure where a scope is inserted through a small incision, providing a direct view of the uterus’s outer surface and surrounding organs. This helps identify subserosal fibroids or other pelvic issues contributing to infertility.
Treatment Approaches for Fertility Preservation
When uterine fibroids are a factor in infertility, treatment focuses on preserving or improving conception ability. Myomectomy, a surgical procedure to remove fibroids while leaving the uterus intact, is the preferred approach for women who wish to become pregnant. The method depends on the fibroid’s location and size.
For submucosal fibroids in the uterine cavity, hysteroscopic myomectomy removes them through the cervix using a scope. For intramural or subserosal fibroids, laparoscopic or open abdominal myomectomy may be performed. These surgical interventions restore normal uterine anatomy, improve the implantation environment, and alleviate blockages.
Medication management can also play a role, though it does not offer a long-term fertility solution. Gonadotropin-releasing hormone (GnRH) agonists, such as leuprolide, can temporarily shrink fibroids and reduce associated bleeding by inducing a temporary menopause-like state. While these medications help manage symptoms, fibroids often regrow after treatment stops; they are typically used before surgery to reduce fibroid size or manage bleeding.
Uterine Fibroid Embolization (UFE) blocks the blood supply to fibroids, causing them to shrink. However, UFE’s impact on future fertility is unpredictable, and it is not recommended for women planning future pregnancies due to concerns about ovarian function and pregnancy outcomes. The most suitable treatment plan is developed in consultation with a reproductive endocrinologist or gynecologist specializing in fibroids, considering individual circumstances and fertility goals.