Uterine polyps, also called endometrial polyps, are usually small, bulb-shaped masses of endometrial tissue, attached to the uterus by a stalk. They are soft, as opposed to uterine fibroids, which can grow much bigger and are made of hard muscle.
When symptoms of uterine polyps are apparent, they're similar to those of more serious conditions, such as endometrial cancer, so if you have these symptoms it's important that you see a doctor. The symptoms may include several types of abnormal uterine bleeding such as:
- Heavy menstrual bleeding
- Spotting between periods
- Bleeding after intercourse
- Bleeding after menopause
Who is at Risk?
The exact cause of uterine polyps is unknown, but they are sensitive to the hormone estrogen. You may be more likely to develop polyps if any of the following are true:
- Age 40 to 50
- Pre- or peri-menopausal
- Obese, or having a body mass index of 30 or more (such as a 5-foot, 9-inch adult weighing 203 pounds)
- Currently or formerly taking an anti-estrogen drug like Nolvadex (tamoxifen).
High blood pressure and the presence of cervical polyps were at one time also cited as risk factors. But a study published in the November 2008 issue of the American Journal of Obstetrics and Gynecology did not find an association between those conditions and uterine polyps.
However, a small study published in Maturitas: The European Menopausal Journal in 2007 did link the chance of malignancy in uterine polyps to high blood pressure and obesity in women who did not have breast cancer or take tamoxifen.
Fewer than 1% of all uterine polyps are associated with cancer.
An article published in a 2008 issue of the American Journal of Obstetrics and Gynecology found a relationship between hormone replacement therapy (HRT) and uterine polyps, but other studies have not found HRT during menopause to be a risk factor.
Uterine Polyps and Infertility
Infertility is defined as the inability to conceive after 1 year of trying. When a woman is infertile and has no symptoms of uterine polyps, the chance that she has asymptomatic polyps is between 3% to 5%, according to the Jones Institute of Reproductive Medicine. If she's experiencing abnormal bleeding, it's more likely that polyps are present.
Uterine polyps can act like a natural intrauterine device (IUD), preventing a fertilized egg from implanting in the uterine wall. They can also block the area where the fallopian tube connects to the uterine cavity, preventing sperm from traveling into the tube to meet the egg. Similarly, they can block the canal of the cervix, which would prevent sperm from entering the uterus at all. Polyps may also play a role in miscarriage for some women.
In a study published in 2005 in the journal Human Reproduction, women undergoing artificial insemination after having their polyps removed became pregnant at about twice the rate of women who did not have their polyps removed. In fact, the women who had their polyps removed often became pregnant without artificial insemination.
Diagnosis and Treatment
Your doctor may recommend one of several methods for finding out whether you have uterine polyps:
- Hysterosalpingogram (HSG): An exam using an x-ray, in which a radiologist injects a contrast dye into the uterus and fallopian tubes to make it easier to see polyps and other tissue.
- Ultrasound: Insertion of a wand-like device into the vagina that sends out high-frequency sound waves to create images.
- Sonohysterogram: A special type of ultrasound in which the radiologist fills the uterine cavity with saline using a narrow catheter. The saline distends the cavity (like a balloon) and creates a space between the walls. This aids in visualizing polyps that may be missed with traditional ultrasound.
- Hysteroscopy: A procedure using a scope inserted through the vagina into the uterus to view the polyps and determine their size and extent. Part or all of a polyp can also be removed for microscopic examination by inserting instruments through the hysteroscopic tube.
- Excision through traditional methods: A sample of a polyp may be obtained through curettage (scraping or scooping) or biopsy (removing tissue via an instrument resembling a drinking straw), or after a hysterectomy (removal of the uterus).
Examination of tissue under a microscope is the only way to reliably determine whether a polyp is benign (noncancerous) or malignant (cancerous).
Some polyps disappear on their own. When removal is necessary to control bleeding, to increase pregnancy odds or to check for cancer, curettage guided by a hysteroscope is often recommended, according to the University of Michigan Health System.
A more conventional method, dilation and curettage (D&C), or scraping the uterine lining, is also still in use.
Hysteroscopy is generally performed using either local or no anesthesia, but general anesthesia is sometimes used as well. After hysteroscopy, you may experience slight bleeding and mild cramps, but you should be able to resume normal activities right away, with the possible exception of intercourse, which you may need to avoid for a week or two if your doctor advises.
When polyps are too numerous for hysteroscopic removal, hysterectomy may be recommended.
There is no specific method for preventing uterine polyps, although keeping yourself at a healthy weight, with normal blood pressure readings are the best methods of lessening your risk factors.
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