Uterine fibroids, also known as leiomyomas or myomas, are common, non-cancerous growths that develop in or on the uterus. These benign tumors are composed of muscle and fibrous tissue, varying widely in size from microscopic to large masses that can fill the entire uterus. Fibroids are highly prevalent, affecting a significant number of women during their reproductive years. Some estimates suggest they are diagnosed in up to 70% of white women and over 80% of women of African ancestry by age 50. While many individuals with fibroids experience no symptoms, others may encounter issues such as heavy bleeding or pelvic pain.
How Fibroids Impair Conception
Fibroids can interfere with conception, depending on their size and location. Submucosal fibroids, which grow just beneath the uterine lining and protrude into the uterine cavity, can significantly distort the uterine shape. This distortion may hinder the proper implantation of an embryo. These fibroids can also affect blood flow to the endometrial lining, further impeding implantation.
Intramural fibroids, located within the muscular wall of the uterus, are the most common type. Large or numerous intramural fibroids can alter the overall shape of the uterus, potentially affecting the transport of sperm or eggs, or disrupting the uterine contractions necessary for conception. Such fibroids might also compromise the blood supply to the uterine lining, hindering implantation.
Subserosal fibroids develop on the outer surface of the uterus. These fibroids generally have less impact on fertility unless they become very large and press on nearby reproductive organs, potentially blocking them. Fibroids can also alter the shape of the cervix, which might affect sperm entry.
Identifying Fibroids When Trying to Conceive
Identifying fibroids often begins with a doctor’s examination and a review of symptoms. Imaging techniques are then commonly used to confirm the presence and location of fibroids. Ultrasound serves as the diagnostic tool due to its accessibility and effectiveness in visualizing the uterus and any growths.
For a clearer view of the uterine cavity, a sonohysterography, also known as saline infusion sonography (SIS), may be performed. This procedure involves introducing saline into the uterus, which helps outline the cavity and reveal submucosal fibroids. Magnetic Resonance Imaging (MRI) offers more detailed mapping of fibroids, providing comprehensive images of the uterus and surrounding structures. For direct visualization and sometimes removal of certain fibroids, minimally invasive procedures like hysteroscopy, which involves inserting a camera through the cervix into the uterus, or laparoscopy, which involves small incisions in the abdomen, may be utilized.
Treatment Approaches for Fertility
When fibroids are affecting fertility, treatment often focuses on their removal to improve the chances of conception. Myomectomy is a surgical procedure aimed at preserving fertility by excising only the fibroids while leaving the uterus intact. This surgery can be performed abdominally, laparoscopically, or hysteroscopically, with the approach depending on the fibroid’s size, number, and location. Hysteroscopic myomectomy is used for submucosal fibroids, while laparoscopic or abdominal approaches address intramural and subserosal fibroids.
Uterine Artery Embolization (UAE) is an alternative procedure that blocks the blood supply to fibroids. While effective for symptom relief, UAE is not recommended for individuals actively trying to conceive, as its impact on future fertility and pregnancy outcomes is less clear compared to myomectomy. Medications, such as GnRH agonists, can temporarily shrink fibroids by reducing estrogen levels. These medications are temporary but may be used before surgery to reduce fibroid size. For small, asymptomatic fibroids, a “watchful waiting” approach, or expectant management, may be recommended, involving regular monitoring without intervention.
Navigating Pregnancy with Fibroids
For individuals who conceive with fibroids, the presence of these growths can introduce considerations during pregnancy. Fibroids may grow or undergo degeneration during pregnancy due to hormonal changes, which can lead to pain. This pain results from a process called red degeneration, where the fibroid outgrows its blood supply.
Complications associated with fibroids during pregnancy include a risk of miscarriage. There is also a risk of preterm labor and placental abruption. Fibroids can affect fetal positioning, leading to malpresentation, and may increase the need for a Cesarean section. In some cases, fibroids can also contribute to postpartum hemorrhage. Management during pregnancy is conservative, focusing on pain relief and monitoring, as surgical removal of fibroids during pregnancy is avoided due to the risks involved.