Your guide to understanding uterine fibroids or polyps

Overview

Uterine fibroids and polyps are two types of non-cancerous growths that develop on the womb (uterus). They are very common, affecting 20-50% of women over 30. They are made up of fibrous tissue and range in size from that of a seed to that of a small ball. We take a look the causes, symptoms and treatments.

What are uterine fibroids or polyps?

Uterine fibroids are small growths that develop in or around the womb (uterus). In the majority of cases, they are non-cancerous (benign). The growths attach themselves to the wall of the uterus and vary in size from a few millimetres to several centimetres. They are made up from tissue, such as muscle.

Sometimes, you will also see uterine fibroids called myomas or leiomyomas.

Uterine polyps are also small growths that develop in or around the womb. But where fibroids are made of connective tissues and muscle cells, polyps are made of endometrium, which is the lining of the uterus. They are more common in women who have been through the menopause, although women who are younger can also get them. 

What are the types of uterine fibroids?

There are several types of uterine fibroids. Each is determined by its location in the womb. The three main types are:

• Intramural fibroids: These grow within the muscle wall of the womb and are the most common type of fibroid
• Subserosal fibroids: These develop on the outside of the womb and can grow into the pelvis
• Submucosal fibroids: These form in the muscle layer that sits beneath the womb’s inner lining and they grow into the cavity of the womb

Both subserosal and the submuscosal fibroids have a narrow stalk of tissue that attaches them to the womb. These stalks are called pedunculated fibroids.

What causes uterine fibroids?

The growth of uterine fibroids has been linked to the hormone oestrogen, although the exact cause is still unknown.

Fibroids tend to develop when your oestrogen levels are at their highest, which is usually during a woman’s reproductive years (from around 16 to 50 years of age). Oestrogen is the female reproductive hormone and is produced by the ovaries.

As the oestrogen levels in your body rise and fall, it causes the lining of your womb to thicken and then break down during your period. Polyps can form when the lining grows too much.

When the oestrogen levels are low, fibroids tend to shrink. This typically occurs after the menopause when the menstrual cycle stops. As such, age is a common contributing factor. Women in their 40s and 50s are more likely to develop uterine fibroids.

Other factors that put you in a higher risk of developing fibroids include:

• Being overweight (obesity increases the amount of oestrogen produced)
• High blood pressure
• Taking tamoxifen, which is breast cancer medication

What are uterine fibroids symptoms?

Most women who develop uterine fibroids are unaware that they have them. This is because in most cases the growths do not produce any symptoms.

However, around one in three may experience some of the following uterine polyp symptoms:

• Painful or heavy periods
• Pain in the lower tummy
• Pain in the lower back
• Frequent need to urinate
• Constipation
• Discomfort or pain during sex

How do you diagnose uterine fibroids?

Because fibroids generally don’t cause any symptoms, they are usually found during a routine gynaecological examination. 

If you are showing symptoms that could indicate fibroids, the first stage of diagnosis is usually performed by your GP, who will carry out a pelvic examination to look for any obvious signs. You may then be referred to a hospital for further tests. These tests could include:

Ultrasound scan

 An ultrasound scan uses high-frequency sound waves to create an image of the inside of your body. The scanner transmits images to a small monitor so that the doctor and see if there are any signs of fibroids.

There are two types of ultrasound scan that are used to diagnose fibroids:

• Abdominal ultrasound scan: The ultrasound probe is moved over the outside of your abdomen
• Transvaginal ultrasound scan: A small probe is inserted into your vagina

If an ultrasound scan suggests that you might have fibroids, then the doctor may refer you to a gynaecologist for further tests.

Hysteroscopy

A hysteroscopy uses a small telescope, called a hysteroscope, to look inside your womb. It is inserted through the vagina and cervix. Because the procedure looks inside the womb, it is used to diagnose submucosal fibroids.

It is normally performed without the need for an anaesthetic, although you may be given a local or general anaesthetic. Most women don’t feel any pain during the procedure, although you may experience some cramping.

Laparoscopy

This is a minimally invasive surgical procedure and a highly effective tool for diagnosing gynaecological conditions. During a laparoscopy, a small telescope with a camera and light source on one end is put into the body. A surgeon will make a small incision in your abdomen so that the laparoscope can be inserted. It is performed under a general anaesthetic.

The camera relays images of the inside of your abdomen to a monitor. This enables the surgeon to examine the organs and tissue inside your body.

Biopsy

In some cases during a hysteroscopy or laparoscopy a small tissue sample will be removed. This is called a biopsy. The tissue sample can then be looked under a microscope for further examination.

What treatments are available for uterine fibroids?

In most cases, fibroids will disappear without the need for treatment. If you are experiencing any symptoms caused by fibroids then medicine will be the first course of action. As well as helping to relieve the symptoms, some medication can also help shrink the fibroid.

The types of medicine that you may be offered to treat the symptoms of fibroids include:

• Levonorgestrel intrauterine system (LNG-IUS): A small plastic device is inserted into your womb that slowly releases progestogen hormone levonorgestrel. It works by preventing the womb lining from growing so quickly, making your periods lighter
• Tranexamic acid: These tablets work by preventing the blood vessels in the womb lining from bleeding
• Anti-inflammatory medicines: Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can be taken reduce any pain
• The contraceptive pill: The birth control pill stops the ovaries from releasing an egg. It also makes bleeding during period lighter
• Oral progestogen: This prevents the womb lining from growing quickly
• Injected progestogen: Available as an injection to treat heavy periods, it prevents the lining of your womb from growing quickly

Medications to help shrink fibroids include: 

• Gonadotropin releasing hormone analogues (GnRHas): This works by affecting the pituitary gland, which stops the ovaries from producing oestrogen. GnRHas stop your menstrual cycle
• Ulipristal acetate: This is used to treat fibroids is you have moderate or severe symptoms. If medication has been ineffective and your symptoms are severe, your doctor may suggest surgery

There are several different surgical procedures available to treat fibroids, including:

• Hysterectomy: In this procedure, the womb is removed. It is an effective way of preventing fibroids from returning. However, you will only be offered this type of surgery if you do not want to have any more children. It is only used to treat large fibroids and severe bleeding
• Myomectomy: This is an alternative to a hysterectomy. During this surgical procedure, the fibroids are removed from the wall of the womb. However, it is not suitable for all types of fibroid
• Hysteroscopic resection of fibroids: A thin telescope (hyperoscope), which is fitted with small surgical instruments, is used to remove the fibroids from inside the womb. Because the hysteroscope is inserted through the vagina and cervix, it requires no incisions to be made in the abdomen
• Hysteroscopic morcellation of fibroids: This procedure is similar to a hysteroscopic resection, except that is uses an instrument called a morcellator to cut and remove the fibroid

As well as surgical techniques outlined above, there are several non-surgical, minimally invasive treatments for fibroids. These include:

• Uterine artery embolisation: This is carried out by a radiologist and involves blocking the blood vessels that supply the fibroids, causing them to shrink
• Endometrial ablation: This is minor procedure to remove the lining of the womb. Different methods are used to remove the lining, such laser or a heated wire loop. It can be used to treat small fibroids

What are the complications of uterine fibroids with relation to pregnancy?

In some cases, large fibroids can affect your ability to become pregnant by blocking the fallopian tube. Some treatments, such as a hysterectomy, will also have an impact on your ability to bear children.

Fibroids can also lead to some difficulties during pregnancy. This can lead to problems with the development of the baby or difficulties during labour. In some rare cases, it may lead to a premature labour or a caesarean section may be necessary.

Your consultant will discuss all the available treatments and the impact that they might have on you before you begin any treatment.

Get help for uterine fibroids or polyps

A consultation with an experienced gynaecologist is often the quickest and simplest way to resolve your problem. They will be able to diagnose the cause of your pain and talk with you about the best treatment options for your specific situation. To book an appointment with one of our experienced specialists, call us directly or use our online booking system.

To find out more about uterine fibroids, download our Women's Health Matters report.