Overview
Uterine polyps are growths on the inner wall of the uterus that expand into the uterine cavity. The condition is mostly the result of overgrowth of cells in the lining of the uterus (endometrium). These polyps are considered noncancerous (benign), but in some cases, they can be potentially cancerous.
The size of the polyps ranges from a few millimetres (the size of a sesame seed) to several centimetres (the size of a golf ball). They remain attached to the wall by a large base or a thin stalk.
There can be one or many uterine polyps, which usually stay attached within the uterus but may slip through the opening of the uterus (the cervix) into the vagina. The condition is quite common in women reaching menopause or who have reached or completed menopause. It is important to diagnose the condition to ensure it is detected early. There are several testing methods explained in this article.
What are Uterine Polyps?
Uterine polyps, also known as endometrial polyps, are attached to the lining of the uterus by a large base or thin stalk. These growths are characterised by a core of fibrous stroma and thick-walled blood vessels, covered by endometrial epithelium (endometrial cells). These cells may be “functional,” meaning they respond to hormones and bleed during a period, or “nonfunctional,” meaning they remain as is regardless of the cycle.
They can cause -
- Irregular menstrual bleeding
- Bleeding after menopause
- Heavy menstrual flow or bleeding between periods
In addition, it can also lead to infertility, pelvic pain, and foul-smelling discharge. Some polyps may also grow more than 4 cm (Giant polyps).
What are the Symptoms of Uterine Polyps?
The signs and symptoms of uterine polyps are mostly related to their effect on the uterine lining and blood vessels. While some symptoms may remain silent (asymptomatic) and are only discovered during routine examination, most manifest through variations in the menstrual cycle.
Primary Clinical Symptoms
The most common symptom of uterine polyps is Abnormal Uterine Bleeding (AUB). This occurs when the polyps' fragile blood vessels rupture or interfere with the normal shedding of the lining.
- Intermenstrual Bleeding: Spotting or light bleeding that occurs between scheduled menstrual periods.
- Irregularity in Menstruation: The menstrual cycle can vary significantly in length or unpredictably at times.
- Menorrhagia: Abnormally heavy or prolonged menstrual flow that may interfere with daily activities.
- Postmenopausal Bleeding: Any amount of vaginal bleeding or spotting after a woman has reached menopause (this is considered a critical sign that requires immediate medical intervention).
Secondary Symptoms
Beyond bleeding, polyps can cause physical discomfort or reproductive challenges. The symptoms depend on the size and location of the growth within the uterus.
| Symptoms | Description |
|---|---|
| Dysmenorrhea | Cramping and pelvic pain caused by the uterus trying to expel the growth |
| Infertility | Large or multiple polyps may block the fallopian tubes or prevent embryo implantation |
| Leukorrhea | Increased vaginal discharge that may appear watery or be tinged with blood |
Note: Clinicians emphasize that symptom severity does not always correlate with polyp size. A very small 5 mm polyp can cause significant daily spotting, while a much larger 3 cm polyp might only cause slightly heavier periods.
What Causes Uterine Polyps?
Hormonal factors are one of the common reasons that lead to the development of uterine polyps. Here are some reasons that may contribute to the development of the condition -
Localised Aromatase Overexpression
Current research highlights that polyps express high levels of the aromatase p450 enzyme. This enzyme converts androgens into estradiol locally within the polyp tissue. This creates a high-estrogen microenvironment even if a woman’s blood hormone levels appear normal.
Progesterone “Gap”
Beyond just “high estrogen,” polyps are characterised by a deficiency in progesterone receptors (PR). Without enough receptors, the endometrium cannot receive the “stop” signal that progesterone usually provides. Thus, leading to “unopposed” estrogenic growth.
Epigenetic Silencing
New studies point to the silencing of tumour-suppressor genes such as PAX2 through DNA methylation. This molecular alteration prevents cells from undergoing apoptosis (programmed cell death). Thus, allowing the polyps to persist and grow.
Xenoestrogen Impact
Exposure to endocrine-disrupting chemicals also increases the risk of polyps. Those “xenoestrogens” bind to receptors and trigger excessive cell division, causing uterine polyps to grow.
Coexisting Gynaecological Disease
Conditions associated with high estrogen levels, such as PCOS and endometriosis, are also risk factors.
Stress and the HPA Axis
The hypothalamic-pituitary-adrenal (HPA) axis produces and regulates the stress hormone cortisol. Any dysregulation of the HPA axis can cause disturbance to the sex hormones, which can lead to the growth of uterine fibroids or make the symptoms worse.
Premenopause, Menopause, and HRT
Most people assume that when they reach menopause, the decline in estrogen causes the symptoms. However, estrogen can fluctuate rapidly, sometimes rising above the average. Thus, causing uterine polyps.
Inflammation
Endometrial polyps may form due to chronic endometrial inflammation. The condition is associated with elevated levels of inflammatory markers relative to a normal endometrium and also includes growth factors and activated mast cells. Inflammation often causes new blood vessels to form and tissue to grow, which might lead to polyps in the uterus.
How are Uterine Polyps Detected?
Uterine polyps are detected through several imaging tests and clinical evaluation. Here are the most commonly used methods to detect uterine polyps -
Transvaginal Ultrasound
A transvaginal ultrasound involves inserting a wand-like device through the vagina. The device is known as a transducer, which creates images of the uterus, ovaries, and fallopian tubes through sound waves.
However, it can be difficult to differentiate a polyp from general thickening of the uterine lining (hyperplasia).
Hysterosonography
This test involves using a thin, flexible tube (catheter) to inject salt water (saline) into the hollow part of the uterus. Then the healthcare provider will use a probe to get the images of the inside of the uterus.
The saline distends the uterine walls. Thus, creating a "black" (anechoic) background that clearly outlines the "white" polyp. It allows the clinician to measure the dimension and identify the attachment point (pedicle). This helps plan the surgery properly.
Hysteroscopy
Hysteroscopy uses a thin, flexible, lighted telescope (hysteroscope) that is inserted through the vagina and cervix into the uterus. It allows the healthcare provider to visualise the interior of the uterus by eliminating the shadows often seen on ultrasound.
Endometrial Biopsy
This test involves a suction catheter, which is used to collect a specimen from inside the uterus. Sometimes it may be considered helpful, but it may miss the polyps.
Curettage
A curet is a long metal instrument used to collect tissue from the inner wall of the uterus. The instrument has a small loop on the tissue that helps scrape the tissue or polyps. The extracted tissue determines if the cancer cells are present.
Currently, tests are moving towards less invasive and more automated detection methods. This reduces patient discomfort. Some of them are -
- 3D/4D Power Doppler Imaging: It is done to visualise the “single feeding vessel.” This helps in confirming if it is a polyp or a fibroid.
- AI-Assisted Hysteroscopy: New AI algorithms are being integrated into hysteroscopic cameras to create “real-time histology.” These systems analyse the vascular patterns of a polyp during the exam to alert the surgeon instantly if the tissue looks suspicious for malignancy.
- Liquid Biopsy: Liquid biopsy, also known as uterine washes, is a test process where fluid is collected and screened for molecular biomarkers. This allows detection of pre-existing cellular changes before they are large enough to be seen on ultrasound.
Do Uterine Polyps Need to be Removed?
It depends. If the polyp is considered low risk (in case a person is pre-menopausal), it doesn’t need to be removed. If a person is post-menopausal and is experiencing symptoms, such as abnormal bleeding, the doctor may suggest polyp removal surgery. Doctors may also suggest removing the polyps if it might be a risk to fertility.
Fertility Impact of Polyps
A uterine polyp is considered an obstacle to successful conception and pregnancy. There are three major ways through which polyps impair fertility -
Structural Interference
If the polyps are large, they can interfere with the internal ostia (the openings of the fallopian tubes). Thus, preventing sperm from reaching the oocyte. Also, if the polyp is located near the fundus, it can distort the structure of the uterine cavity. This makes it difficult for a fertilised embryo to find a suitable location for attachment.
The Hostile Endometrium
Recent studies (2025) suggest that polyps trigger a localised inflammatory response. This increases the presence of glycodelin. It is a glycoprotein that inhibits sperm-binding to the zona pellucida of the egg. Also, uterine polyps may alter the expression of the HOXA10 and HOXA11 genes, which are important markers of endometrial receptivity during the implantation window.
Impact on Outcomes of Pregnancy
Research in the Fertility and Sterility journal suggests that even if the implantation occurs, polyps may cause early miscarriage. The irregular vascularisation of the polyp can cause localised bleeding and subchorionic hematomas. Thus, causing destabilization of the early gestational environment.
Note: Current medical data suggests that surgical removal (hysteroscopic polypectomy) is a highly effective fertility-enhancing procedure. This helps restore natural fecundity within 3-6 months after the operation.
How are Uterine Polyps Treated?
Treatments for uterine polyps mostly depend on the symptoms and other factors that might increase the risk of uterine cancer. If a person is still in their reproductive years and the polyp is not causing symptoms, then the doctors may not need to treat it. Rather, it is monitored closely. There is a high chance that the polyp may go away on its own.
However, if a person is going through menopause and the polyps are causing symptoms, too, then they might need thorough treatment. Here are some treatment methods used -
- Medication: Doctors may prescribe certain hormonal medications, such as progestins and gonadotropin-releasing hormone agonists. These may reduce the symptoms. But they are usually a short-term solution that might return once the medication is stopped.
- Uterine Polypectomy: Sometimes the doctors may remove the polyp during hysteroscopy. It is a procedure in which the provider inserts instruments to cut and remove the polyp. It is a precise procedure guided by visual images. The removed polyps are then sent to the lab to check whether they are cancerous.
- Surgery: A person may need additional surgery if the polyp is cancerous. During the surgery, the uterus is removed to prevent the cancer cells from spreading to other organs.
Many patients ask, “Can uterine polyps be prevented?” Well, the answer is no. There is no guaranteed way to prevent uterine polyps, as they are generally driven by hormonal and genetic factors. However, there are certain clinical practices that can help detect the condition early, such as -
- Baseline ultrasound
- Annual pelvic examinations
- Weight management
- Insulin sensitivity
Conclusion
Uterine polyps are estrogen-sensitive growths in the uterine lining. The diagnostic method has evolved, and current medical evidence shows the invention of new techniques. From transvaginal ultrasound to SIS (Saline Infusion Sonohysterography) and Diagnostic Hysteroscopy, all methods allow identification of subtle sessile or flat polyps that are often missed during blind biopsies.
Moreover, 3D Doppler imaging helps identify the single feeding vessel within the polyp stalk. Depending on the test results, the doctors may prescribe medication or surgery. For patients concerned about fertility, the removal of the polyp does more than just clear the path.