Ask the expert: what are fibroids?

Fibroids, also known as uterine fibroids, affect around one in five women in the UK aged between 30 and 50. Here we’ll explore what they are, symptoms to look out for, and how they’re diagnosed and treated. 

What are fibroids?

Fibroids are non-cancerous growths in and around your womb (uterus) that can cause heavy or painful periods. Your womb is made of three layers: an outer layer (perimetrium), a middle muscle layer (myometrium) and an inner lining (endometrium). Fibroids develop from the myometrium and vary in number and size, from as small as a pea to as large as a melon.

Are there different types of fibroids?

There are three main types of fibroids.

Intramural fibroids are the most common and reside in the myometrium, while subserosal fibroids project into the pelvis and submucosal fibroids project into the womb cavity.

Subserosal and submucosal fibroids can also be pedunculated, which means they're attached to your womb via a stalk of tissue.

What are the symptoms of fibroids?

Symptoms of fibroids vary considerably from one person to the next. It is common to have no symptoms, however, around one in three women will experience mild, moderate or severe symptoms. The severity of your symptoms depends on the size, location and number of fibroids in your womb. 

If you have large fibroids, they may push against other organs in your pelvis, such as your bladder — causing you to urinate more often — or your bowel, which can lead to constipation. 

If your fibroids are close to or inside your womb cavity, your periods may be heavy and/or painful. Sometimes, these fibroids can also cause infertility by preventing sperm from reaching an egg or by preventing a fertilised egg from attaching to the womb lining. In rare cases, fibroids can lead to a miscarriage.  

Other common symptoms of fibroids include abdominal pain, lower back pain, and pain or discomfort during sex.

If you’re pregnant, your fibroids may temporarily increase in size and cause more pain. Depending on their location and size, they may also interfere with childbirth (labour) and increase your risk of premature labour. 

How are fibroids diagnosed?

As most women with fibroids don’t have any symptoms, fibroids are often detected incidentally during an investigation for something else or during a routine gynaecological examination. 

If you have fibroid symptoms, see your GP. They will ask about your symptoms and medical history and perform a pelvic examination. This involves gently pressing against your abdomen to feel for changes in the shape of your womb that could be the result of fibroids.

If necessary, they may then refer you for an ultrasound scan, either an abdominal ultrasound scan, where a small handheld probe is pressed over your abdomen, or a transvaginal ultrasound scan, where a different probe, which is slightly larger than a tampon, is inserted into your vagina. 

Depending on the results of your ultrasound scan, you may need to have further investigations via a hysteroscopy or laparoscopy. 

When should fibroids be treated?

If your fibroids aren’t causing you any symptoms, there is usually no need for treatment. If you have symptoms, treatment will depend on their severity, as well as the location and size of your fibroids. 

If you’re nearing menopause and your symptoms are manageable, you may not need treatment as fibroids usually shrink after menopause and so your symptoms may go away on their own. 

Treatment options include uterine fibroid embolisation (UFE) or surgery, specifically a myomectomy or hysterectomy. 

What is a myomectomy?

A myomectomy is a type of surgery where the womb is preserved and only the fibroids are removed.

If your fibroids are in your womb cavity (submucosal fibroids), you may be able to have a minimally invasive myomectomy, where a thin, telescope-like device with a light and a camera on the end (hysteroscope) is inserted into your womb via your vagina. Special surgical instruments are then inserted through the hysteroscope to remove the fibroids.

If you have fibroids in the muscle layer of your womb (intramural fibroids) or on the outer surface of your womb (subserosal fibroids), a myomectomy will involve making a cut into your abdomen through which surgical instruments can be passed to remove your fibroids. Depending on the size and number of fibroids you have, this can be performed using keyhole surgery (laparoscopy), which is less invasive and has a faster recovery time than traditional surgery.

What are the risks of a myomectomy?

A myomectomy is effective at removing fibroids, however, as your womb remains intact, there is a chance that your fibroids may return after several years.

During your myomectomy, your fibroids are likely to bleed during removal as they have a strong blood supply. Although bleeding can be controlled in most cases, occasionally bleeding is extensive and uncontrollable and the entire womb needs to be removed (hysterectomy).

What is a hysterectomy and when it is needed?

A hysterectomy involves removing the entire womb. This is usually recommended if you have many or recurrent fibroids or very large fibroids, and you do not want to become pregnant in the future. It can be performed via keyhole or traditional surgery, depending on the size, location and number of your fibroids.

What is uterine fibroid embolisation (UFE)?

UFE involves inserting a small tube (catheter) into the blood vessels that supply your fibroids. Small particles are then injected via the catheter into these blood vessels to cut off the blood supply to your fibroids. Over several months the fibroids will shrink causing your symptoms to ease off.

This procedure is often offered as an alternative to a hysterectomy for women who want to retain the ability to become pregnant in the future.

Can fibroids be treated without surgery?

There are currently no medications that can be taken in the long term to treat fibroids. However, occasionally, certain medications (ie gonadotropin-releasing hormone agonists or ulipristal acetate) are given to shrink fibroids before surgery to remove them as this helps reduce bleeding.