Uterine polyps (endometrial polyps) – what they are, why they develop and how they are treated

Uterine polyps are a type of growth that develops in the endometrium (the inner lining of the womb). Most of the time they aren't cancerous, but we've decided to talk about them because they can affect women at any age.

It's important to keep an eye on them, as uterine polyps can cause problems with your menstrual cycle and your fertility. So here you'll find out what symptoms to look out for, what complications are possible and what treatment options are available.

 What are uterine polyps?

Uterine polyps are growths (new tissue formations) that develop on the inner wall of the womb, known as the endometrium – hence the name endometrial polyps. There may be a single polyp or several.

They develop through excessive growth of the cells of the womb lining and can extend into the uterine cavity. Usually they stay there, but there are also cases where they pass through the cervix and reach into the vagina.

Depending on how quickly and in what way they grow, their size varies from a few millimetres (like millet or sesame seeds) to several centimetres (like a table tennis ball or larger).

Although they can be malignant (precancerous polyps), in most cases they are benign. They can often cause cycle irregularities and bleeding, which we'll look at in more detail shortly.

Uterine polyps vs cysts

Cysts are also a type of growth, but unlike polyps they are filled with fluid (or semi-solid material) from the reproductive system. While uterine polyps form on the womb lining, these cysts develop in the ovaries – hence the name ovarian cysts, on which we've prepared a detailed article with comprehensive information HERE.

In short, the main differences between uterine polyps and ovarian cysts are:

• Where they form: polyps occur in the womb, cysts form on the ovaries.
• Contents: polyps are tissue growths, cysts are fluid-filled sacs.
• Effect on menstruation: polyps are more likely to cause heavy bleeding than cysts.
• Level of pain: pain isn't a typical symptom of polyps, whereas cysts can cause dull or sharp pain.

Uterine polyps vs fibroids

Uterine fibroids are more similar to polyps than cysts are: they also occur in the womb and are likewise benign (not cancerous). But here too there are clear differences, including:

• Composition: polyps consist of endometrial tissue, fibroids of connective tissue and smooth muscle cells.
• Size: polyps start out the size of seeds and can grow to the size of a golf ball, whereas fibroids start out the size of apple pips and can grow as large as a grapefruit or bigger.

The symptoms: although many symptoms are similar, fibroids can cause considerably more pain as they grow and press against the womb.

Why do uterine polyps develop – causes

It isn't known exactly when or why a polyp may develop in the womb. Research currently doesn't know what causes these growths to develop.

What we do know, however, is that hormones play an important role in the growth of these polyps, and that polyps respond to fluctuations in oestrogen.

Think of it this way: your oestrogen levels rise and fall over the course of your menstrual cycle and directly affect how the endometrium builds up each month. The way this endometrial tissue thickens is certainly connected in some way to the growth of polyps.

The higher the oestrogen level in the body, the greater the risk that uterine polyps will grow more.

Risk factors for uterine polyps

Based on what we've explained about oestrogen fluctuations, the first risk factor is of course oestrogen. The greater the amounts of oestrogen acting on the body, the higher the risk of uterine polyps. Other risk factors include:

• Perimenopause or postmenopause
• Hormone therapy to treat menopausal symptoms
• Being overweight
• High blood pressure
• Certain breast cancer treatments (tamoxifen)

Symptoms of uterine polyps

Cycle irregularities are the most common symptom of uterine polyps. They can cause numerous changes to your monthly bleeding, such as:

• Irregular cycle: you never know when your period will come or how heavy it will be.
• Heavy bleeding: an unusually heavy menstrual flow – known medically as menorrhagia. Although every woman is unique and there's no standard amount of blood lost during menstruation, you can tell whether your flow has changed by comparing it with your previous periods. You can find out more about how to spot these changes in our article on the difference between menorrhagia and normal menstruation.
• Bleeding between periods: this may be light bleeding or spotting, which may in turn point to a health problem or be entirely normal. Besides uterine polyps, there are many other reasons why you might notice bleeding outside your period, and it isn't always cause for concern. You can read more about bleeding between periods HERE.
• Bleeding after sex
• Bleeding after the menopause: spotting or blood-stained discharge after the menopause, pink, red or brownish. In theory, the menopause means that ovarian function ends and the menstrual cycle stops, which is why bleeding ceases. Beyond the medical explanation, however, the menopause is a very personal experience and brings with it numerous changes, which we've told you more about in an article on the menopause, its symptoms and treatment.
• Infertility: as a consequence of cycle irregularities.

Whatever type of bleeding uterine polyps cause, we recommend always using natural period products that won't make the situation worse. Toxic chemicals in conventional products (dyes, bleaches, plastic) can cause irritation and upset the vaginal flora, making the discomfort even worse.

Choose to care for your intimate area with 100% organic ingredients and no harmful substances. Enroush pads and tampons are made from 100% highly absorbent organic cotton and have a neutral pH to protect your vaginal microbiome with the purest ingredients. That way you're protected day after day not just against leaks, but against irritation and allergies too.

Pain occurs only very rarely. Polyps become painful when they grow significantly. The discomfort is felt in the abdomen or lower back, rather like period pain.

It's also possible for uterine polyps to cause no symptoms at all, meaning there's no sign that anything is wrong.

In that case, there are two ways your gynaecologist might discover them: either they're found by chance during an examination to diagnose another problem, or the polyps become visible after slipping through the cervix.

When should you see a doctor?

In principle, without symptoms you won't know that you have uterine polyps unless they're discovered by chance during an examination. But whether you know about the uterine polyps or not, always speak to your doctor if you experience cycle irregularities and unusual bleeding:

• Spotting or bleeding between periods
• Spotting or bleeding after the menopause
• An unusually heavy and unpredictable menstrual flow

Complications of uterine polyps

This condition can't cause many complications, but the best-known effect concerns fertility.

Infertility and miscarriage are sometimes associated with uterine polyps. The logical explanation is that, because they grow on the endometrial tissue, they can interfere with the correct implantation of the fertilised egg. They can also block the cervix and the fallopian tubes. Removing them could increase the chances of pregnancy, although the evidence isn't conclusive in this respect.

Cancer can also be a consequence of these growths. As a rule, polyps aren't malignant (that is, they're benign), but there are cases where they do become malignant, in which case the complication is naturally cancer.

Diagnosing uterine polyps

If there's a suspicion that you have uterine polyps, your doctor will first assess the symptoms you've noticed. You may be asked questions about the following:

• The type of medication you're taking, if you're receiving treatment
• Whether you still have a menstrual cycle: whether you still have periods or you're through the menopause
• How long your periods last and how far apart they are, if you still have them
• Bleeding between periods or spotting
• Any pain or discomfort
• Changes in your menstrual flow: whether it's heavier than usual
• Bleeding or spotting, if you're already through the menopause

Once this information is available, your gynaecologist may arrange further tests to confirm the diagnosis. These may include a gynaecological examination, a smear test (cervical screening) and other investigations such as:

Transvaginal ultrasound

In this examination, an ultrasound probe is inserted into the vagina. It produces an image of the inside of the womb so that the doctor can see whether there are any abnormal growths or formations present.

A transvaginal ultrasound may also be followed by a sonohysterography. This is a painless, non-invasive procedure in which a sterile fluid is introduced into the womb through a thin tube. This fluid expands the uterine cavity and so allows an even clearer picture of any growths inside.

Hysteroscopy

This involves inserting a long, thin tube, known as a hysteroscope, through the vagina and cervix into the womb. It's a specialist optical instrument that allows the gynaecologist to view the inside of the womb and make an accurate diagnosis.

Endometrial biopsy

A biopsy means that a sample is taken and examined in a laboratory. For an endometrial biopsy, the gynaecologist uses special instruments to take a sample of the endometrial tissue, which is then examined in the laboratory and – if present – allows abnormal cells to be identified.

You should also bear in mind that there are many other conditions that can cause abnormal discharge and bleeding. Because the examinations described above allow the womb to be assessed as a whole, other causes can also be identified, including cysts or fibroids.

All these problems must first be ruled out, and only then can a diagnosis of uterine polyps be made. For this reason, any other conditions that may be present are treated before the polyps are assessed and treated:

• Ovarian cysts
• Uterine fibroids
• Adenomyosis
• Endometriosis
• Bleeding disorders
• Hormonal disorders
• Hypothyroidism
• Being overweight

Treatment of uterine polyps

Treatment for uterine polyps depends on your stage of life and isn't always necessary. What your gynaecologist does depends on how these growths develop and what symptoms they cause.

What's more, there are cases where polyps disappear on their own. Below we explain what should be done in each situation.

 Monitoring the patient

This is the most common approach for women who still have periods. If you have no symptoms and the polyps aren't causing discomfort or affecting your cycle, your doctor won't treat them but will simply monitor them.

This means that the development of the polyps is kept under review through regular check-ups. Further investigations are only carried out in certain circumstances, for example if they grow larger or if there's a risk of womb cancer.

Medical treatment

Medical treatment is particularly chosen for women who have reached the menopause and are experiencing symptoms. These are treatments with progestogens or with GnRH antagonists (gonadotrophin-releasing hormone antagonists), which are intended to maintain hormonal balance.

Hormone therapy can ease the bleeding and shrink the polyps, but it's only a temporary solution. Once the treatment ends, the symptoms usually return.

Surgical treatment

This is called a uterine polypectomy and involves the surgical removal of the endometrial polyps. It's carried out during a hysteroscopy and involves cutting out the growths in order to remove them. Although you may feel a certain amount of pressure during the procedure, you'll be given medication beforehand so that it isn't painful.

Surgical removal of polyps is particularly recommended if unusual bleeding occurs after the menopause, or if they're having a negative effect on a pregnancy or on your ability to conceive.

After a polypectomy, the polyps can be sent to a laboratory and examined to check whether there are any signs of cancer. If cancer cells are found, a hysterectomy – the surgical removal of the womb – may be required.

How can we prevent uterine polyps?

In short: you can't prevent uterine polyps. As they have no clear cause, prevention is impossible. What you can do, however, is see your gynaecologist regularly so that they can be detected early and kept under review.