Endometrial polyps are abnormal growths that develop from the tissue lining the inside of the uterus, known as the endometrium. They are common, especially in women during their reproductive years, and can affect a woman’s ability to conceive. This article explores the relationship between these growths and difficulty achieving pregnancy, including potential mechanisms and available treatments.
Characteristics of Endometrial Polyps
Endometrial polyps are localized overgrowths of endometrial tissue, consisting of glands, fibrous tissue, and blood vessels. They attach to the inner wall of the uterus either by a thin stalk (pedunculated) or a broad base (sessile). These growths vary significantly in size, ranging from a few millimeters up to several centimeters; multiple polyps may be present.
The vast majority of polyps are benign, though a very small percentage may contain precancerous or cancerous cells. Polyps are estrogen-sensitive, meaning their growth is influenced by the hormone estrogen. While most frequently diagnosed in women approaching or past menopause, they also occur in younger women trying to conceive.
Polyps often cause no noticeable symptoms and may be discovered incidentally during imaging. When symptoms are present, the most common is abnormal uterine bleeding. This can manifest as irregular menstrual periods, unusually heavy flow, or spotting between cycles.
Direct Links Between Polyps and Infertility
Endometrial polyps interfere with conception and successful pregnancy through distinct biological and mechanical mechanisms. Mechanical interference occurs when the physical presence of the polyp acts as an obstruction within the uterine cavity. A polyp near the fallopian tube opening (cornual area) may physically block the path of sperm as they travel toward the egg, while larger polyps can hinder sperm movement toward the upper reproductive tract.
The primary theory explaining the link to infertility involves the disruption of embryo implantation, which is the process where a fertilized egg attaches to the uterine wall. Polyps are thought to act like a foreign body inside the uterus, preventing the successful embedding of an embryo. Studies show that women with polyps who undergo fertility treatments, such as in vitro fertilization (IVF), have lower success rates compared to women without them.
Polyps can also create an altered uterine environment that is less receptive to pregnancy. The presence of the polyp can induce a chronic, localized inflammatory response within the endometrium. This inflammation may lead to changes in hormone receptors and the production of specific inhibitory factors, which negatively affect the endometrial receptivity required for implantation.
Detection and Management of Polyps
The initial diagnostic tool for identifying endometrial polyps is often a transvaginal ultrasound. To enhance the clarity and accuracy of the ultrasound, a procedure called saline infusion sonography (SIS), or hysterosonography, is frequently used. This involves injecting a sterile saline solution into the uterus to gently expand the cavity, which allows for a much clearer visualization of any growths on the lining.
The most definitive method for both diagnosis and immediate treatment is hysteroscopy. During this procedure, a thin, flexible, lighted telescope is inserted through the cervix into the uterus, allowing the physician to directly visualize the entire uterine cavity. This direct view is highly accurate for confirming the presence and precise location of the polyps.
The standard management for polyps causing fertility issues is surgical removal, known as hysteroscopic polypectomy. This procedure is typically performed using instruments inserted through the hysteroscope, which allows the physician to precisely excise the polyp while preserving the surrounding healthy endometrial tissue. For women with unexplained infertility, the removal of polyps significantly improves the chances of both natural conception and successful outcomes with fertility treatments.