What are uterine polyps and what drives them?
In this article we will find out exactly what uterine polyps are, the typical signs and symptoms, as well as the underlying hormonal drivers and how they differ from fibroids.  Finally, we’ll look at how to treat uterine polyps and some tips you can start straight away at home.
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What Are Uterine Polyps?
A uterine (or endometrial) polyp is an abnormal growth containing glands, stroma (connective tissue) cells and blood vessels projecting from the lining of the uterus. They can be any size and can grow large enough to fill the uterine cavity. Polyps greater than 4 cm are considered giant polyps. They are found during both reproductive and postmenopausal phases of life.Â
Uterine polyps can be pedunculated (attached to the endometrium by a stalk) or sessile, where they have a large flat base attached to the endometrial surface. Polyps can also form in the cervix.
How Common Are Uterine Polyps?
Uterine polyps are thought to affect approximately 25% of women however around 82% show no symptoms.Â
Polyps have been associated in 13-50% of cases of abnormal uterine bleeding and 35% of cases of infertility.
What Are the Symptoms of Uterine Polyps?
As we mentioned above, you may not experience symptoms with uterine polyps – around 82% of women with polyps show no symptoms. However, common symptoms include:
- Heavy menstrual bleeding –The majority of premenopausal women with endometrial polyps complain of abnormal uterine bleeding,Â
- Spotting between periods – usually spotting at odd times during the menstrual cycle as the polyp itself can bleed or irritate the surrounding tissue. It’s important to note that spotting can also be due to low progesterone levels, or an imbalance of estrogen and progesterone. Also oral contraception and IUDs, STIs, stress and fibroids can cause spotting.
- Infertility – polyps can interfere with implantation of the embryo.
Uterine Polyps vs Fibroids: What's the Difference?
Uterine polyps and fibroids are often thought of as one of the same conditions, however, whilst a lot of the drivers for the conditions are the same they can have different symptoms and require different treatments.Â
Fibroids are made of smooth muscle, while polyps are made of the thin tissue that lines the uterus (endometrial tissue). Polyps are more common once you reach your 40s and 50s, while fibroids tend to occur in women around 30 to 50 years old.
Some of the symptoms overlap so it can be hard to tell if you have a fibroid or a uterine polyp. Both conditions can cause heavy or irregular bleeding and problems with fertility but fibroids are more likely to cause pain and bloating. Fibroids are also more likely to grow larger than a uterine polyp and could end up requiring major surgery so it is very important to have them investigated and diagnosed.Â
It is also possible to have both a uterine polyp(s) and fibroids. Research shows that 1 in 5 women with uterine polyp(s) also have fibroids.Â
Another important difference between a fibroid and a uterine polyp is that polyps have a low risk of malignancy, especially in the postmenopausal period. Malignant transformation can occur in 0 to 13% of uterine polyps so it is always important to get checked out if you have any symptoms of either uterine polyps or fibroids.
What Are the Causes and Drivers of Uterine Polyps?
The exact cause of endometrial polyps is unknown, and it is believed that several factors are involved. It is thought that genetic and epigenetic factors involving enzyme and metabolic activities may cause polyps to develop. Risk factors include advanced age, obesity, hypertension, and tamoxifen use ( a chemotherapy drug used in breast cancer treatment).
We will look more closely at the possible drivers of Uterine Polyps.
1) High Estrogen
One of the biggest drivers for uterine polyp development and growth is high estrogen levels or unopposed estrogen resulting from low progesterone.Â
Uterine polyp glandular cells have been found to have a higher concentration of estrogen receptors (and decreased expression of progesterone receptors) compared with normal endometrial cells.
Find out more about high estrogen and estrogen dominance here.
There are many ways estrogen has been shown be involved in driving uterine polyps;
- Age: Uterine polyps are more commonly seen between the ages of 40-49 which typically coincides with the perimenopausal years where estrogen is high and not balanced out by progesterone. Read more about the four stages of perimenopause.
- Aromatase expression: Aromatase is an enzyme that converts androgens into estrogens. It is thought that some women can over express this enzyme, causing higher levels of estrogen. It has been shown that uterine polyps express the aromatase p450 enzyme, which stimulates the conversion of testosterone into estradiol (a type of estrogen), which can induce the growth of uterine polyps.
- Obesity: The ovaries produce the majority of estrogens in women before menopause, however estrogen can also be made and secreted by white adipose tissue (fat tissue). So, having a high amount of body fat can lead to high estrogen levels. Obesity is also associated with increased estrogen production via increased levels of aromatase which converts androgens in fat to estrogen.Â
- Endocrine disrupting toxins: Synthetic xenoestrogens are endocrine disrupting chemicals which act like estrogen in the body, leading to higher levels of estrogen. BPA and phthalates are examples of xenoestrogens found in plastic but others can be found in cleaning products, pesticides and hygiene products such as shampoos. Research has found exposure to phthalates is associated with increased risk of uterine polyps. Find out more about Environmental Toxins and hormone health here
- Coexisting gynaecological diseases: diseases associated with high estrogen levels such as PCOS and endometriosis are also a risk factor for uterine polyps.
Testing your estrogen levels and estrogen detoxification with a comprehensive hormone test like the Advanced Hormone Test can help you understand if high estrogen is a factor for you.
2) Poor Estrogen Detoxification
Overall estrogen levels only provide part of the picture. It’s important also to look at overall estrogen detoxification (sometimes called estrogen metabolism).
In the first phase of estrogen detoxification, our estrogen can travel down three different pathways: the 2-OH, the 4-OH and the 16-OH. The 16-OH-E1 binds more tightly to estrogen receptors than the other metabolites. If too much estrogen is metabolised down this pathway, then it may lead to increased uterine polyp growth as well as other symptoms such as heavy bleeding and breast tenderness.Â
Estrogen detoxification can only be tested in a urine test like the Advanced Hormone Test, it can not be detected in blood serum.
Find out more about estrogen metabolites and how they are metabolised.
3) Stress and the HPA Axis
Did you know that stress can disrupt our hormones and therefore be a driver of uterine polyps?Â
Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which produces and regulates our stress hormone cortisol, can cause disturbances to our sex hormones. For example, high cortisol levels have been shown to delay ovulation, which in turn causes low progesterone and unopposed estrogen. This can drive the growth of uterine fibroids or make the symptoms of them worse.Â
4) Progesterone
Progesterone plays an important role in counterbalancing the effects of estrogen. This means that low progesterone levels can lead to the effects of estrogen being magnified (what we call unopposed estrogen) and make the symptoms of uterine polyps worse.Â
Ideally, progesterone should be around 100x higher than estrogen in the second half of the cycle. Find out more about low progesterone and estrogen balance here.
Low progesterone levels can often be confused for uterine polyps because they share a key symptom: intermenstrual spotting. If you’re experiencing spotting between cycles it’s important to test progesterone levels in the second half of the cycle to rule this out.
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5) Perimenopause, Menopause and HRT
Many people assume that when they start the transition into menopause (aka perimenopause), it is a decline in estrogen that is causing their symptoms.Â
However, in the early stages of perimenopause it’s actually progesterone that is the first level to drop as ovulation becomes more sporadic. Estrogen can actually fluctuate wildly up and down, sometimes rising higher than at any other time in our reproductive lives. Therefore, estrogen dominance is extremely common in the early stages of perimenopause. And as we have seen, it is estrogen that can drive uterine polyps.Â
You can read more about the signs and symptoms of perimenopause and the four stages of perimenopause.Â
Perimenopause, HRT and Testing
For women with uterine polyps, the right HRT drug, dose and regimen is crucial to avoid polyp growth and the symptoms possibly related to it.
For example, Tibolone (which is an oral synthetic hormone used to treat symptoms of menopause), has been shown to have a three-fold risk for the occurrence of uterine polyps compared to taking no hormonal medication.Â
If you’re considering HRT in perimenopause, it’s important to test your hormones first to understand which hormones you need. Many women are prescribed estrogen hormone therapy in perimenopause, balanced by a synthetic progestin. However, as we have seen, it’s likely you’re experiencing high estrogen and low progesterone in early perimenopause, so this combination will just compound estrogen dominance, making uterine polyps and their symptoms worse.
6) Inflammation
Endometrial polyp formation may be the result of localised chronic inflammation in the endometrium. Uterine polyps have an increased number of inflammation markers compared to a normal endometrium including growth factors and activated mast cells. Inflammation results in the formation of new blood vessels and growth of tissue, which could result in the development of uterine polyps.
7) Oxidative Stress
Markers for oxidative stress have been shown to be higher in patients with uterine polyps.
Treatment of Uterine Polyps
Conventional Treatment of Uterine Polyps in the NHS
Hormonal Contraception
Contraceptive use, in general, has been shown to decrease the risk of getting uterine polyps as they suppress the hormones which have been shown to drive them; estrogen, progesterone and testosterone.Â
However, while the contraceptive pill can help with the symptoms of uterine polyps, such as heavy bleeding, it does have its downsides. By suppressing your hormones, you are missing out on all the benefits that your natural hormones provide. Estrogen plays an important role in maintaining your cardiovascular, reproductive and bone health whilst progesterone reduces inflammation, has a calming effect on the body, helps with sleep and supports the thyroid, bones and brain. The oral contraceptive pill has also been shown to cause an imbalance in the gut microbiome, cause nutrient deficiencies and have a negative impact on bone density.
Polyp Removal
Surgeries such as dilation and curettage (D&C) or a polypectomy are usually used to remove uterine polyps. These will then often be biopsied to check that they are benign.Â
It’s important to note that new polyps will develop in at least 30% of people who have previously had polyps, which is why it’s important to also address the underlying hormonal drivers of this condition alongside their removal.
The FUTURE WOMAN approach to addressing Uterine Polyps
In order to address the underlying drivers of your uterine polyps, we would first recommend testing with a comprehensive hormone test such as the Advanced Hormone Test.
At FUTURE WOMAN, all our hormone tests are paired with a personalised healthplan prepared by expert nutritionists. This means that we can recommend specific supplement, diet and lifestyle advice to target the underlying drivers of your uterine polyps for lasting change.Â
By addressing your drivers we can support a reduction in the chance of returing polyps, help to shrink exisiting polyps and reduce symptoms.Â
Some markers which we would focus on include:
- Estrogen: As we have seen, estrogen can fuel the growth of uterine polyps, so we would look at your overall estrogen levels to see if they are elevated. Â
- Phase 1 estrogen metabolism: We’re specifically interested in the 16-OH pathway which is more likely to be elevated.
- Progesterone: As well as indicating whether or not ovulation took place, the balance of progesterone to estrogen is key. We are looking for progesterone to be at least 100x higher than estrogen in the luteal phase of the cycle (the second half).Â
- Androgen levels, including testosterone and androstenedione. As we have seen, they can be aromatised into estrogens. So elevated androgens can lead to elevated estrogens.
- Cortisol and the HPA axis: We look at free cortisol, your daily cortisol pattern and metabolised cortisol to get a clear picture of your HPA axis. An elevated cortisol pattern would usually indicate current stress whereas very low cortisol might indicate more of a long term stress picture.
- Quinolinate: This marker correlates with phthalate metabolite concentrations, which we have seen can be a risk factor for uterine polyps
- Inflammation and oxidative stress. These have both been shown to be a possible driver for uterine polyp growth.
3 Tips to Help with Uterine Polyps
- Test and address your unique hormone imbalances. Understand if a hormone imbalance could be driving your uterine polyps and their symptoms and address those directly with a qualified practitioner like those at FUTURE WOMAN. Is it low progesterone? High estrogen? Sluggish estrogen metabolism? Or all 3?
- Remove ALL fragrances. This means candles, scented body wash, scented body creams, scented soaps, scented cleaning products and more. You can always add a few drops of essential oils to unscented products to make them smell amazing! You can find some great alternatives on our FUTURE WOMAN shop.
- Eat the rainbow. Eating a wide variety of different coloured fruits and vegetables will provide you with antioxidants and polyphenols which have been shown to help reduce inflammation and oxidative stress, both of which are implicated in uterine growth.
References
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Lv, M., Yu, J., Huang, Y., Ma, J., Xiang, J., Wang, Y., Li, L., Zhang, Z., & Liao, H. (2022). Androgen Signaling in Uterine Diseases: New Insights and New Targets. Biomolecules, 12(11), 1624.Â
Nair, V., Nigam, J. S., Bharti, J. N., Dey, B., & Singh, A. (2021). Giant Endometrial Polyp in a Postmenopausal Woman. Cureus, 13(1), e12789.Â
Nijkang, N. P., Anderson, L., Markham, R., & Manconi, F. (2019). Endometrial polyps: Pathogenesis, sequelae and treatment. SAGE open medicine, 7, 2050312119848247.Â
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Vitale, S. G., Haimovich, S., Laganà , A. S., Alonso, L., Di Spiezio Sardo, A., Carugno, J., & From the Global Community of Hysteroscopy Guidelines Committee (2021). Endometrial polyps. An evidence-based diagnosis and management guide. European journal of obstetrics, gynecology, and reproductive biology, 260, 70–77.Â
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