Types of Uterine Fibroids

Intramural fibroids are the most common type, accounting for approximately 70% of all uterine fibroids. They develop within the myometrium, the muscular wall of the uterus, and can range in size from a few millimetres to over 20 centimetres in diameter.

Small intramural fibroids may cause no symptoms at all. As they grow, however, they can cause heavy menstrual bleeding, pelvic pressure, urinary frequency, and abdominal distension. Very large intramural fibroids that extend towards the uterine cavity (intramural-submucosal) are particularly likely to cause heavy periods.

Intramural fibroids respond well to uterine fibroid embolisation (UFE) and can also be treated with myomectomy or, in severe cases, hysterectomy. The choice of treatment depends on the size and number of fibroids, the severity of symptoms, and the patient’s individual preferences and reproductive plans.

Subserosal fibroids develop on the outer surface of the uterus, growing outward into the pelvic cavity. Because they do not typically distort the uterine cavity, they are less likely to cause heavy menstrual bleeding than submucosal or intramural fibroids.

Instead, subserosal fibroids tend to cause pressure-related symptoms. As they enlarge, they can press on neighbouring organs, leading to urinary frequency (when pressing on the bladder), constipation (when pressing on the rectum), back pain, and abdominal distension. Very large subserosal fibroids can grow to a considerable size before causing symptoms, as they have space to expand within the pelvic and abdominal cavity.

UFE is an effective treatment for subserosal fibroids, as is laparoscopic or open myomectomy. The treatment approach is guided by the size and location of the fibroid and the patient’s symptoms and preferences.

The location of fibroids within the uterus is one of the most important factors in determining the most appropriate treatment. A thorough assessment with MRI imaging allows our team to accurately classify each fibroid and develop a tailored treatment plan.

For example, small submucosal fibroids may be best treated with hysteroscopic resection, while multiple intramural fibroids are often ideally suited to UFE. Large subserosal fibroids may require surgical removal if they are causing significant pressure symptoms. In many cases, a combination of approaches may be recommended.

At the North London Fibroid Clinic, we offer the full range of treatment options and work with each patient to develop a personalised plan based on their specific fibroid type, symptom profile, and individual goals. To discuss your options, visit our treatment options page or book a consultation.