Intramural Fibroid Symptoms, Pregnancy, & Treatment

Intramural fibroids are located within the uterine wall. Some intramural fibroids can enlarge to span from the outer serosal surface, through the uterine wall, and all the way to the endometrium (the mucosal surface). These are known as transmural fibroids. In one study of 96 Italian women with fibroids, intramural fibroids were the most prevalent type of fibroid identified on transvaginal ultrasound [4].

According to the International Federation of Gynecology and Obstetrics (FIGO) classification system, there are two types of fibroids that are completely intramural, however submucosal and subserosal fibroid types both have intramural components as well.

• Fibroid Type 1: Submucosal, <50% intramural
• Fibroid Type 2: Submucosal, ≥50% intramural
• Fibroid Type 3: Contact with endometrium, 100% intramural
• Fibroid Type 4: Intramural
• Fibroid Type 5: Subserosal, ≥50% intramural
• Fibroid Type 6: Subserosal, <50% intramural

Most cases of uterine fibroids do not cause noticeable symptoms. However, women that do experience intramural fibroid symptoms will generally experience heavy menstrual bleeding, bleeding in between periods, pelvic pain, and/or low back pain. Women with enlarged intramural fibroids may also experience ‘bulk’ symptoms, including bloating, a feeling of fullness, urinary urgency, or constipation caused by the fibroid(s) pressing against the stomach, the bladder, or other nearby organs [4].

While intramural fibroids do not distort the uterine cavity, they are associated with reduced fertility outcomes compared to women without fibroids. However, the effect of intramural fibroids on pregnancy is not as significant as with submucosal fibroids [2]. Many women with uterine fibroids have a successful pregnancy with intramural fibroids, but complications such as miscarriage, c-section, preterm labor and postpartum hemorrhage occur in approximately 10 to 40% of pregnancies when fibroids are present [5, 6].

Intramural fibroid treatments vary from conservative medical therapy, to minimally invasive interventions, to surgical removal of the entire uterus. The optimal treatment for your intramural fibroid will depend on your desire to preserve fertility, your age, any other existing medical issues, ability to take time off for recovery, as well as other factors. Some therapies treat symptoms while others eliminate the fibroids completely. Some treatment options, while less invasive, may require subsequent treatment or re-intervention. These are all factors to consider when deciding which intramural fibroid treatment option is best for you, and some treatment options are only viable for certain types of fibroids.

Medications

The most conservative intramural fibroid treatment option is medical therapy. Medicine can be effective if intramural fibroid symptoms are mild, if a woman is in perimenopause (so treatment is only needed in the short term), or if pre-operative intervention to reduce the size of the fibroids would make a surgery less technically challenging [7, 8]. Nonsteroidal anti-inflammatory drugs (NSAIDs), hormones (estroprogestins or progestogens), and oral contraceptives can help with symptomatic bleeding and fibroid pain. Gn-RH analogues and selective progesterone receptor modulators (sPRMs) like ulipristal acetate (UPA) help treat bulk symptoms such as pelvic pressure, pelvic pain, and frequent urination [9]. Medical treatments are only used for the short-term due to the significant health risks associated with long-term use of these medicines [7].

Uterine Fibroid Embolization

Myolysis

Myolysis is also called fibroid ablation. It uses a concentrated energy source such as ultrasound, radiofrequency, or laser to cause fibroid tissue destruction. MRI or ultrasound imaging help guide where the energy source should be directed. Myolysis decreases menstrual bleeding and uterine fibroid size [7]. However, it can only treat one fibroid at a time, and large fibroids greater than 8 cm in diameter may not respond well [9]. In addition, myolysis targets the central portion of the fibroids even though studies have shown that fibroids tend to grow from their peripheries [9].

Myolysis does impact future fertility and pregnancies. As fibroid tissue is destroyed with myolysis, scar tissue can form in the endometrium. While some women may achieve successful pregnancies, there could be potential complications. Myolysis is not always a definitive intramural fibroid treatment. Surgical intervention may be required down the line [7].

Myomectomy

Myomectomy isn’t without its shortcomings, and isn’t always ideal for women with multiple large fibroids. Failure rates range from 14.5% to 30% at 3 to 4 years’ follow-up [9]. Between 10 and 25 percent of women will require a second fibroid surgery [10]. Still, many women choose myomectomy in order to preserve their uterus for future pregnancies. Most women who have myomectomy are able to have children afterwards.

Hysterectomy

Hysterectomy is the most definitive treatment available for uterine fibroids, particularly for women who have no desire to conceive [7]. It can be very effective for patients with extremely large fibroids or a large quantity of fibroids. However, after hysterectomy, once the uterus or parts of it are removed, pregnancy is no longer possible.