A polyp in your uterus is almost always benign, but it can cause irregular bleeding, heavy periods, and in some cases, difficulty getting pregnant. These small growths develop on the inner lining of the uterus and range from a few millimeters to several centimeters across. Most women with uterine polyps never know they have one, since roughly 82% of cases produce no symptoms at all. But when a polyp does cause problems, the effects depend on its size, your age, and whether you’re trying to conceive.
Symptoms You Might Notice
The most common sign of a uterine polyp is abnormal bleeding. That can look different from person to person. Some women experience bleeding between periods, while others have periods that are unpredictably timed, unusually heavy, or vary in length from month to month. Light spotting is also common. If you’ve already gone through menopause, any vaginal bleeding is considered abnormal and worth investigating, and polyps are one of the most frequent causes.
Uterine polyps are implicated in about 50% of all cases of abnormal uterine bleeding. That doesn’t mean every bleeding irregularity is caused by a polyp, but it does mean polyps are one of the first things doctors look for when bleeding patterns change.
Why Polyps Form
Polyps grow in response to estrogen. Anything that increases your estrogen exposure or disrupts hormonal balance raises your risk. Obesity is a significant factor because fat tissue produces estrogen. Polycystic ovary syndrome (PCOS), high cholesterol, and high blood pressure are also associated with higher rates of polyp development. Polyps can appear at any age, but they’re most common between 40 and 49.
One notable risk factor is tamoxifen, a medication used in breast cancer treatment. While tamoxifen blocks estrogen’s effects in breast tissue, it acts like estrogen inside the uterus, which can promote polyp growth, thickening of the uterine lining, and in rare cases, uterine cancer.
How Polyps Affect Fertility
Polyps are found in 16 to 26% of women with otherwise unexplained infertility. Among women who also have endometriosis, that number jumps to 46%. The connection between polyps and difficulty conceiving isn’t fully understood, but there appear to be both mechanical and chemical effects at play.
Physically, a polyp can interfere with sperm reaching the egg or block an embryo from attaching to the uterine wall. On a hormonal level, polyps seem to lower the uterine lining’s responsiveness to progesterone, the hormone that prepares the uterus for pregnancy. Women with polyps also have lower levels of certain proteins needed for embryo implantation during the critical window when attachment should occur.
The good news: removing the polyp appears to significantly improve your chances. The only randomized trial on this topic found that women who had polyps removed before intrauterine insemination had a pregnancy rate of 63%, compared to 28% for those who didn’t have them removed. Several other studies have also linked polyp removal to improved spontaneous pregnancy rates. For women undergoing IVF, polyps smaller than 2 centimeters may have limited impact on outcomes, though larger ones are typically removed before treatment.
Cancer Risk Is Low but Real
The vast majority of uterine polyps are benign. In premenopausal women, the chance of a polyp being cancerous or precancerous is about 1 to 2%. After menopause, that risk rises to 5 to 6%. Those numbers are low enough that not every polyp needs to be removed, but high enough that doctors take certain factors seriously when deciding on treatment: your age, whether you’ve gone through menopause, the polyp’s size, and whether you have other risk factors for uterine cancer like obesity or PCOS.
How Polyps Are Found
Uterine polyps are often discovered during an ultrasound performed for another reason, such as investigating irregular bleeding or evaluating fertility. A standard transvaginal ultrasound catches about 55% of polyps. Adding saline into the uterus during the ultrasound (called saline infusion sonography) improves accuracy by inflating the cavity so polyps stand out more clearly against the lining.
Hysteroscopy, where a thin camera is inserted through the cervix to view the uterine interior directly, is the most reliable method. It detects about 82 to 86% of polyps and also allows your doctor to remove them during the same procedure. For polyps larger than 1 centimeter, both methods perform reasonably well, but hysteroscopy remains the gold standard because it combines diagnosis and treatment in one step.
When Removal Is Recommended
Not every polyp needs to come out. The decision depends on a few key factors:
- You have symptoms. If a polyp is causing abnormal bleeding or contributing to infertility, removal is the standard approach.
- You’re postmenopausal. Polyps larger than 2 centimeters in postmenopausal women are generally removed because the cancer risk, while still relatively small, is elevated. Smaller polyps in postmenopausal women without risk factors can sometimes be monitored.
- You’re premenopausal with no symptoms. Removal is still considered if you have risk factors for uterine cancer, such as obesity, PCOS, or tamoxifen use. Otherwise, small asymptomatic polyps in younger women may be left alone and monitored over time.
What the Procedure Feels Like
Polyp removal is typically done through hysteroscopy, a minimally invasive procedure that doesn’t require any incisions. A thin, lighted scope is passed through your cervix, and the polyp is cut away from the uterine wall. It’s often performed as an outpatient procedure, meaning you go home the same day.
Afterward, you can expect some cramping and light bleeding that lasts a few days. Feeling faint or mildly nauseous right after the procedure is common. You’ll likely be told to avoid tampons, intercourse, baths, swimming, and hot tubs for about two weeks to reduce infection risk. Most women return to normal activities quickly, though recovery time depends on whether additional work was done during the procedure.
Polyps Can Come Back
One thing to know: polyps have a notable recurrence rate. In one study tracking women after hysteroscopic removal, 43% developed new polyps during the follow-up period. This doesn’t mean the same polyp grew back. Rather, the conditions that caused the first polyp, primarily estrogen stimulation of the uterine lining, can produce new ones over time. If you’ve had a polyp removed, periodic monitoring with ultrasound is a reasonable way to catch any recurrence early, particularly if you originally had symptoms or risk factors.