Endometrial polyps are growths that are attached to the inner wall of the uterus that extend into the uterine cavity. They are usually benign (not cancerous) and are a common finding in women of reproductive age. They range in size from a few millimeters — no larger than a pea — to several centimeters — golf-ball-size or larger.They attach to the uterine wall by a large base (sessile) or a thin stalk (pedunculated). One can have one or many uterine polyps. They usually stay contained within the uterus, but occasionally, they slip down through the opening of the uterus (cervix) into the vagina.
Very rarely, endometrial polyps can be cancerous. I have been treating patients with infertility for more than 25 years and am yet to come across a patient with a polyp that was cancerous.
What are the symptoms of endometrial polyps?
The vast majority of polyps are without any symptoms. Menstrual abnormalities are a common symptom – irregular menses, heavy menses or spotting in between periods. They can also cause infertility.
How common are endometrial polyps?
They can be the only abnormality found in 2 – 3% of infertile women. Some studies have shown polyps to be present in 24% of symptomatic women.
What causes endometrial polyps to develop?
Polyps are rarely seen prior to the onset of menses. Therefore, it is believed that estrogenic stimulation of the uterine lining plays a role in their development. Several molecular mechanisms have also been proposed (overexpression of estrogen and progesterone receptors, endometrial aromatase, and mutation in the HMG1C and HMGI(Y) genes.
How do endometrial polyps cause infertility?
Several mechanisms have been proposed for this:
Mechanical interference with sperm transportation
They act as a space-occupying lesion and interfere with embryo implantation
They induce local inflammatory changes in the uterine lining
They produce glycodelin, a glycoprotein that has been shown to inhibit natural killer cell activity and render the uterine lining less receptive to implantation
How are endometrial polyps diagnosed?
The common techniques used to diagnose endometrial polyps include ultrasound (hysterosonogram), X-rays (hysterosalpingogram) and surgery (hysteroscopy). These have been discussed in detail in a previous blog.
What is the treatment of endometrial polyps?
The treatment is with a surgical procedure called a hysteroscopy. This can be done in the office or in the hospital (usually for large and multiple polyps). The polyp can be removed by using a scissors, an electrical loop (resectoscope) or with a mechanical device (morcellator). All of these work equally well and it is up to the surgeon’s preference to use whichever option.
When can we proceed with an IVF cycle after removal of a polyp?
A recent study by Pereira et al. (Fertil Steril 2015; In Press) looked at the time interval between hysteroscopic removal of a polyp and IVF cycle start. 487 patients were divided into three groups (Group 1 (n = 241; 49.5%) consisted of patients who underwent IVF after their next menses; Group 2 (n = 172; 35.3%) after 2 – 3 menstrual cycles and Group 3 (n = 74; 15.2%) after more than three menstrual cycles.
The patient characteristics in the three groups were similar. The overall pregnancy outcomes were similar for groups 1, 2, and 3: implantation rate (42.4%, 41.2%, and 42.1%, respectively), clinical pregnancy rate (48.5%, 48.3%, and 48.6%), spontaneous miscarriage rate (4.56%, 4.65%, and 4.05%), and live birth rate (44.0, 43.6%, and 44.6%). The authors concluded that there is no advantage in postponing starting an IVF cycle after a endometrial polyp is removed.
Dr. Karande is Board Certified in the specialty of Obstetrics and Gynecology as well as the subspecialty of Reproductive Endocrinology and Infertility. He is a Fellow of the American College of Obstetricians and Gynecologists and Member of the American Society for Reproductive Medicine.