Uterine polyps, also known as endometrial polyps, are growths that develop from the tissue lining the inner wall of the uterus, called the endometrium. These growths are typically non-cancerous and range widely in size. While a polyp does not make pregnancy impossible, it can interfere with conception and successful implantation of an embryo. Understanding how these common growths affect the reproductive environment is important for those attempting to conceive.
How Uterine Polyps Affect Conception
The primary way a uterine polyp can hinder conception is by physically and chemically disrupting the uterine environment necessary for a fertilized egg to attach. The most significant impact is on embryo implantation, the process where the embryo embeds itself into the uterine lining. A polyp acts as a space-occupying lesion, potentially preventing the embryo from finding a receptive area to implant.
Polyps can also create a localized state of chronic inflammation within the uterus. This inflammatory response is thought to make the endometrial lining less receptive to the embryo. Furthermore, polyps may produce substances, such as the glycoprotein glycodelin, which can locally inhibit the biological processes necessary for successful implantation.
The physical location and size of the polyp also play a role in the degree of interference. A polyp situated near the cornual region, where the fallopian tubes open into the uterus, may physically block the sperm’s path or the embryo’s transit into the uterine cavity. Larger polyps or those causing abnormal uterine bleeding are often more likely to be associated with fertility issues.
For women undergoing fertility treatments, removing a polyp often leads to a significant increase in pregnancy rates. One study reported a pregnancy rate of 63% following polyp removal, compared to 28% for women who did not undergo the procedure. This difference highlights the negative influence polyps can have on achieving and maintaining a pregnancy.
Diagnosis and Removal Procedures
A full fertility workup often involves specific imaging techniques to detect polyps, as many are asymptomatic and would otherwise go undiagnosed. The initial diagnostic tool is typically a transvaginal ultrasound, which uses sound waves to create an image of the uterus. This method can sometimes miss smaller polyps or confuse them with the normal thickening of the uterine lining.
To improve visualization, a secondary technique called Saline Infusion Sonography (SIS) or sonohysterography is often employed. This procedure involves injecting a sterile saline solution into the uterine cavity through a thin catheter during the ultrasound. The fluid gently distends the uterus, allowing the polyp to be clearly outlined against the fluid-filled space, making it easier to confirm its presence, size, and location.
The gold standard for both confirming the diagnosis and providing simultaneous treatment is hysteroscopy. A hysteroscope, a thin tube equipped with a camera, is inserted through the vagina and cervix into the uterus, allowing the physician to directly visualize the entire uterine cavity on a screen. This direct visualization is superior for accurate assessment and guiding subsequent removal.
Polyp removal, known as polypectomy, is typically performed during the hysteroscopy. Specialized instruments, such as surgical scissors or a wire snare, are inserted through the hysteroscope to detach the polyp from the uterine wall. This minimally invasive, outpatient procedure is highly effective, and the tissue is sent for laboratory analysis to confirm it is benign. Following successful removal, the improved uterine environment often translates into a higher chance of conception.
Managing Polyps During Existing Pregnancy
If a woman becomes pregnant while a uterine polyp is present, the polyp is generally monitored rather than immediately removed. Most uterine polyps are benign and do not cause significant problems during pregnancy, but their presence requires careful observation. The polyp’s tissue is prone to bleeding due to the increased blood flow and hormonal changes that occur during gestation.
One of the most common issues associated with polyps in pregnancy is abnormal spotting or light bleeding. While this can be alarming, it is often attributed to the polyp itself rather than a serious complication. In rare cases, the presence of a polyp has been linked to an increased risk of miscarriage or preterm labor, though these outcomes are not common.
Surgical removal of a uterine polyp is typically avoided during pregnancy. The procedure can stimulate uterine contractions or introduce an infection, which could increase the risk of spontaneous late miscarriage or preterm delivery. Removal is usually only considered if the polyp is causing severe, life-threatening hemorrhage that cannot be managed conservatively.