Do Endometrial Polyps Go Away on Their Own?

Endometrial polyps sometimes disappear without treatment, but in most cases they persist. Studies tracking polyps over time report spontaneous regression rates ranging from about 6% to 23%, depending on the population studied and the length of follow-up. The women most likely to see a polyp vanish on its own tend to be younger, premenopausal, and have small polyps. For everyone else, especially postmenopausal women, the odds of a polyp resolving by itself are low enough that a wait-and-see approach needs careful justification.

How Often Do Polyps Actually Disappear?

The research on spontaneous regression gives a surprisingly wide range, largely because different studies used different designs and follow-up periods. A study published in Human Reproduction followed 112 women who had ultrasound-confirmed polyps and chose not to have them removed. Over a median follow-up of about 28 months, only 7 women (roughly 6%) experienced complete regression of their polyps.¹ That is a strikingly low number, and it suggests that for most women, polyps are not going anywhere on their own.

A separate study took a different approach. Researchers re-evaluated 121 women who were scheduled for surgical removal but had to wait before their procedure. When they performed a second-look hysteroscopy before operating, 28 of those women (23%) no longer had a visible polyp.² The higher number here likely reflects the fact that some of the women in this study had smaller polyps and were younger, both of which favor regression. It also demonstrates how the definition of “regression” matters: in this case, the polyp had simply disappeared by the time of the follow-up scope, but the waiting period was shorter than the multi-year follow-up in the Human Reproduction study.

A third study, published in the Journal of Medical Case Reports, found that small polyps measuring 5 to 10 mm had the highest rate of spontaneous regression, and that hormonal drug use was also a factor.³ This lines up with what the other studies found: size matters, and the smaller the polyp, the better the chance it resolves.

Who Is Most Likely to See a Polyp Disappear

If you are premenopausal, under 45, and your polyp is less than 2 cm, the evidence is mildly encouraging. The study that found a 23% regression rate identified all three of those characteristics as significantly associated with spontaneous resolution.² Women who had abnormal uterine bleeding also showed a trend toward more regression, though the researchers acknowledged the association was borderline. The Human Reproduction study similarly observed that premenopausal women and those presenting with abnormal bleeding had higher regression rates, although those differences did not hold up after statistical correction for multiple comparisons.¹

Postmenopausal women, on the other hand, appear to have essentially zero chance of spontaneous regression. In the second-look hysteroscopy study, every single postmenopausal woman still had her polyp at the time of re-evaluation.² That finding makes sense biologically, and it has practical implications: if you are past menopause and told you have a polyp, waiting for it to go away is not a realistic strategy.

Why Most Polyps Persist

To understand why polyps tend to stick around, it helps to know what they are made of. Endometrial polyps are overgrowths of the uterine lining, composed of glands, stroma, and blood vessels. In a normal menstrual cycle, the endometrium thickens in response to estrogen and then sheds when progesterone levels drop. Polyps, however, seem to march to their own hormonal drum.

Research has shown that the stromal cells inside polyps express fewer progesterone receptors compared to the surrounding normal endometrium.⁴ This means the polyp tissue is less responsive to progesterone, the hormone that normally triggers shedding. At the same time, estrogen receptor expression tends to be higher in polyp tissue, creating a hormonal imbalance that favors growth and persistence.⁵ In postmenopausal women, estrogen receptors appear to play a particularly strong role in keeping polyps alive.⁶

This receptor imbalance also explains why premenopausal women with active hormonal cycling have a better shot at regression. Their fluctuating hormone levels might occasionally overwhelm the polyp’s resistance, especially if the polyp is small. In postmenopausal women, without that cycling, there is no natural force working to dislodge the growth.

How Common Are Polyps, and Do They Always Cause Symptoms?

Endometrial polyps are found in roughly 8% of the general female population, based on a Danish study that screened women aged 20 to 74 regardless of symptoms.⁷ That study also found that polyps are more common in postmenopausal women (about 13%) than in premenopausal ones (about 8%). The striking detail: 82% of the women whose polyps were confirmed on biopsy had no symptoms at all.

When polyps do cause symptoms, the most common complaint is abnormal uterine bleeding, which can mean heavier periods, bleeding between periods, or postmenopausal bleeding.⁸ But polyps are also frequently found during workups for other conditions and are common in women without any bleeding complaints at all.⁹ This creates a clinical gray zone: if a polyp is found incidentally and you have no symptoms, the question of whether to treat it or leave it alone becomes genuinely debatable.

When Watchful Waiting Makes Sense

Given the regression data, a reasonable approach for some women is simply to monitor the polyp and reassess in a few months. This strategy is most defensible when the polyp is small (under about 1 cm), you are premenopausal, and you have no symptoms or fertility concerns. Your doctor may repeat an ultrasound in three to six months to see whether the polyp has grown, shrunk, or disappeared.

The case for watchful waiting weakens considerably if you are postmenopausal, if the polyp is larger than 1 to 2 cm, if you have abnormal bleeding, or if you have risk factors for endometrial cancer such as obesity, diabetes, or tamoxifen use. In those scenarios, the low odds of spontaneous regression combined with the need to rule out precancerous or cancerous changes usually tips the balance toward removal.

How Polyps Are Found and Removed

Polyps are typically first spotted on a transvaginal ultrasound, but that test has its limitations. A meta-analysis comparing imaging methods found that standard transvaginal ultrasound has a sensitivity of about 62% and specificity of about 73% for detecting polyps, meaning it misses a fair number and sometimes flags things that are not actually polyps.¹⁰ Saline infusion sonohysterography, where saline is injected into the uterus to improve the ultrasound view, performs better at roughly 87% sensitivity and 86% specificity. Hysteroscopy, where a thin camera is inserted directly into the uterus, is the most accurate method at about 92% sensitivity.¹⁰

Hysteroscopy is also the preferred method for removal. An evidence-based guide on polyp management rated office hysteroscopy as having the highest diagnostic accuracy, particularly in women being evaluated for infertility, and described hysteroscopic polypectomy as feasible and safe with minimal risk of complications like intrauterine adhesions.¹¹ The procedure is often done outpatient and typically requires only local anesthesia or light sedation.

The Cancer Question

One of the main reasons doctors lean toward removing polyps rather than watching them is the small but real chance that a polyp contains precancerous or cancerous cells. A systematic review and meta-analysis pooling data from over 35,000 women found that about 2.7% of endometrial polyps harbored malignancy.¹² That rate was significantly higher in postmenopausal women (about 5%) compared to premenopausal women (about 1%), and higher in women with symptoms (about 5%) than in those without (about 2%).

Individual studies reinforce this picture. In one series of over 1,000 polyps, about 1.3% turned out to be cancer on pathology review.¹³ In another study of 203 polyps removed hysteroscopically, 3 were cancerous and 9 showed atypical hyperplasia, a precancerous state, for a combined premalignant/malignant rate of about 6%.¹⁴

The risk factors that predict malignancy in a polyp overlap heavily with risk factors for endometrial cancer in general. A multi-institutional study found that older age and abnormal uterine bleeding were the strongest independent predictors, with bleeding carrying roughly a three-and-a-half-fold increase in risk.¹⁵ Obesity, hypertension, and postmenopausal status also showed associations. This is why postmenopausal women with polyps are almost always advised to have them removed and sent for pathology, even if the polyp is small and asymptomatic.

Polyps and Fertility

For women trying to conceive, endometrial polyps introduce a separate set of concerns beyond cancer risk. Research has found that polyps reduce the expression of key genes involved in embryo implantation, providing a molecular explanation for why women with polyps tend to have lower pregnancy rates.¹⁶ Even a small polyp can theoretically interfere with an embryo’s ability to attach to the uterine wall.

The clinical data supports removal before fertility treatment. A prospective randomized study of women undergoing intrauterine insemination (IUI) found that those who had their polyps removed beforehand were about twice as likely to become pregnant. Notably, 65% of pregnancies in the polypectomy group occurred before the first IUI cycle even took place, suggesting that simply removing the polyp restored natural fertility for many of those women.¹⁷

In the context of IVF, hysteroscopic polypectomy also appears to improve outcomes. One study found that after polyp removal in women with unexplained infertility, about 65% achieved clinical pregnancy.¹⁸ Another study comparing hysteroscopic polypectomy to blind curettage found higher pregnancy rates with the more precise hysteroscopic approach, with first-transfer pregnancy rates of about 68% versus 51%.¹⁹ If you are dealing with infertility and a polyp has been found, the evidence strongly favors removing it rather than hoping it will resolve on its own.

They Come Back More Often Than You Might Expect

Even after successful removal, endometrial polyps have a well-documented tendency to recur. One study found that 43% of women experienced polyp recurrence after hysteroscopic polypectomy over a follow-up period, with the risk increasing the longer women were followed and the more polyps they had initially.²⁰ That 43% figure reflects a longer follow-up; another study with a different population found an 8% recurrence rate at a median of about 42 months.²¹

Several conditions significantly raise the likelihood of recurrence. Adenomyosis (a condition where endometrial tissue grows into the muscular wall of the uterus) carried roughly a tenfold increase in recurrence risk. Polycystic ovarian syndrome and obesity (BMI of 30 or higher) each raised recurrence risk by about eight to nine times. Tamoxifen use and the presence of uterine fibroids were also significant risk factors.²¹

Chronic endometritis, a persistent low-grade infection of the uterine lining, is another underrecognized driver of recurrence. A prospective study found that women with chronic endometritis had a recurrence rate of about 26% within a year of polypectomy, compared to about 10% in women without the condition. Women with severe chronic endometritis fared even worse, with a recurrence rate close to 35%.²² This suggests that in women who keep developing polyps after removal, testing for and treating chronic endometritis may be worth discussing with your doctor.

Risk Factors That Make Polyps More Likely in the First Place

Understanding what drives polyp formation can help explain both why they persist and why they recur. Tamoxifen, a drug used in breast cancer treatment, is one of the strongest known risk factors. A large study found that premenopausal women using tamoxifen had nearly four times the risk of developing endometrial polyps compared to non-users.²³ Tamoxifen acts as an estrogen agonist in the uterus, essentially stimulating endometrial growth even as it blocks estrogen in breast tissue.

Metabolic syndrome is another significant contributor. A case-control study found that metabolic syndrome was present in about 71% of women with endometrial polyps, compared to about 13% in controls.²⁴ Insulin resistance, higher BMI, and larger waist circumference were all significantly associated with polyp presence. This makes sense given that fat tissue produces estrogen, and excess insulin can promote cell growth.

For postmenopausal women on hormone replacement therapy, the type of therapy matters. Research has shown that certain HRT regimens increase polyp risk, particularly when estrogen is not adequately opposed by a progestogen. Late menopause and obesity further compounded the risk.²⁵ If you are on HRT and a polyp is found, it is worth discussing with your doctor whether adjusting the regimen might reduce the chance of recurrence after removal.

Preventing Recurrence With a Hormonal IUD

One of the more promising strategies for preventing polyp recurrence is the levonorgestrel-releasing intrauterine system (LNG-IUS), commonly known by brand names like Mirena. This device delivers a steady dose of a progestogen directly to the uterine lining, which counteracts the estrogen-driven growth that fuels polyps.

A pilot study that directly visualized polyps via hysteroscopy found that polyps were present in only 37% of women who had an LNG-IUS placed after polypectomy, compared to 80% in controls.²⁶ A larger retrospective study followed over 450 premenopausal women for up to three years after polyp removal. Those who received an LNG-IUS had a recurrence rate of about 3.5%, compared to about 16% in women who did not receive one.²⁷ The recurrence analysis looking at reproductive-age women similarly found that LNG-IUS placement dramatically reduced recurrence odds.²¹

The LNG-IUS is not appropriate for everyone. If you are actively trying to conceive, it obviously defeats the purpose. And it may not be the right choice for women with certain uterine abnormalities. But for premenopausal women who have had a polyp removed and want to minimize the chance of a repeat procedure, it is one of the strongest evidence-based options available. It also addresses heavy menstrual bleeding, which frequently coexists with polyps, making it a particularly practical choice for women dealing with both problems.

1
Human Reproduction. The natural history of endometrial polyps
2
PubMed Central. Endometrial polyps: Is the prediction of spontaneous regression possible?
3
PubMed Central. Predictive factors of spontaneously regressed uterine endometrial polyps during the waiting period before hysteroscopic polypectomy
4
PubMed. Estrogen and progesterone receptor expression in endometrial polyps
5
PubMed. Impact of estrogen and progesterone receptor expression on the incidence of endometrial polyps
6
PubMed. Immunohistochemical expression of estrogen and progesterone receptors in endometrial polyps and adjacent endometrium in postmenopausal women
7
PubMed. Prevalence of endometrial polyps and abnormal uterine bleeding in a Danish population aged 20-74 years
8
PubMed Central. Endometrial polyps: Pathogenesis, sequelae and treatment
9
PubMed. Endometrial Polyps and Abnormal Uterine Bleeding (AUB-P): What is the relationship, how are they diagnosed and how are they treated?
10
PubMed Central. Comparison of diagnostic accuracy of saline infusion sonohysterography, transvaginal sonography, and hysteroscopy in evaluating the endometrial polyps in women with abnormal uterine bleeding
11
PubMed. Endometrial polyps. An evidence-based diagnosis and management guide.
12
PubMed. The risk of malignancy in uterine polyps: A systematic review and meta-analysis
13
PubMed. Risk and predictors of malignancy in women with endometrial polyps
14
PubMed Central. Malignancy risk factors based on endometrial polyp
15
European Journal of Gynaecological Oncology. Predictors of malignancy in endometrial polyps: a multi-institutional cohort study
16
PubMed Central. Endometrial polyps affect uterine receptivity
17
Human Reproduction. Endometrial polyps and their implication in the pregnancy rates of patients undergoing intrauterine insemination: a prospective, randomized study
18
PubMed Central. Impact of Hysteroscopic Polypectomy on IVF Outcomes in Women with Unexplained Infertility
19
PubMed Central. Pregnancy Rates after Hysteroscopic Endometrial Polypectomy versus Endometrial Curettage Polypectomy: A Retrospective Study
20
PubMed Central. Factors Influencing the Recurrence Potential of Benign Endometrial Polyps after Hysteroscopic Polypectomy
21
Medical Science Monitor. Comprehensive Analysis of Risk Factors for Recurrence in Women of Reproductive Age Undergoing Hysteroscopic Polypectomy
22
PubMed Central. Chronic endometritis multiplies the recurrence risk of endometrial polyps after transcervical resection of endometrial polyps: a prospective study
23
PubMed Central. Risk of Endometrial Polyps, Hyperplasia, Carcinoma, and Uterine Cancer After Tamoxifen Treatment in Premenopausal Women With Breast Cancer
24
PubMed. The association between endometrial polyps and metabolic syndrome: a case-control study
25
PubMed. The role of hormone replacement therapy in endometrial polyp formation
26
PubMed. The Role of the Mirena Intrauterine Device in the Management of Endometrial Polyps: A Pilot Study
27
PubMed. Prevention of Benign Endometrial Polyp Recurrence Using a Levonorgestrel-releasing Intrauterine System in Premenopausal Patients: A Retrospective Cohort Study