Uterine polyps refer to overgrowths of endometrial glands and stroma within the uterine cavity. They are growths that develop in the lining of the uterus (endometrium) and protrude into the endometrial cavity. While they are usually benign they can cause symptoms that require treatment Although these polyps are considered benign, there is a small risk of malignant transformation.
They range in size from a few millimetres-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 can be present anywhere in the uterine cavity location being fundal, utero-tubal junction, posterior lateral or anterior uterine wall and cervical.
Polyps are rarely seen prior to the onset of menses. The exact cause of uterine polyps is unknown but several factors may contribute to its development. Hormonal imbalances particularly an excess of estrogen relative to progesterone are though to play a significant role 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. Other potential factors include chronic inflammation of uterine lining, genetics and certain medical conditions like obesity and hypertension
Symptoms
It is one of the most common causes of abnormal uterine bleeding although women with endometrial polyps may also be asymptomatic. Presentation maybe as follows
- Abnormal uterine bleeding
- Pelvic pain particularly during menstruation
- Infertility
- Changes in menstrual patterns
- Bleeding after menopause
Infertile women are more likely to be afflicted with endometrial polyps than fertile women
Diagnosis
- Transvaginal Ultrasound – Findings on ultrasound may appear nonspecific with diffuse or localized, echogenic endometrial thickening
- Hysteroscopy – Minimally invasive procedure in which a thin, lighted tube is inserted through the cervix into the uterus allowing the doctor to visualize the uterine lining directly and remove the polyp for biopsy
- Saline-infusion sonography (SIS)
How does a polyp affect fertility?
The mechanisms through which endometrial polyps contribute to infertility, however, remain uncertain. Altered endometrial environment and intracavitary bleeding caused by the endometrial polyps have been proposed as explanations for the defect in embryo implantation potentials
Several mechanisms have been proposed
- 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
Management of Polyps in Infertile Women undergoing IVF?
Hysterscopic polypectomy is the treatment of choice as the polyp can be removed under vision in comparison to a D&C where the entire polyp maybe not be removed even after curettage
The relatively high prevalence of endometrial polyps in infertile women scheduled for IVF suggests a causative relationship between the presence of endometrial polyps and infertility
The location of endometrial polyps may influence the pregnancy rate. The pregnancy rate after endometrial polypectomy was highest for polyps located at the utero-tubal junction (57.4%), followed by 40.3% for multiple polyps, 28.5% for posterior uterine wall polyps, 18.8% for lateral uterine wall polyps, and 14.8% for anterior uterine wall polyps
No difference was found in the pregnancy or miscarriage rate after hysteroscopic polypectomy for small polyps (≤10 mm) compared to larger or multiple polyps. No study has established criteria for the size of polyps that should be removed or could be observed in infertile women. However, small endometrial polyps (<10 mm) sometimes regress spontaneously Therefore, the American Association of Gynecologic Laparoscopists guideline states that management of endometrial polyps may be conservative, with up to 25% of polyps regressing, particularly if they are less than 10 mm in size.
