Endometrial or uterine polyps are very common in reproductive-age women and one of the most common causes of abnormal uterine bleeding, such as bleeding between periods. These polyps are an overgrowth of the inside lining of the uterus which is called the endometrium. Although endometrial polyps are almost always benign, it is possible that they can be premalignant or malignant. When an endometrial polyp is removed, it is sent to the laboratory for review to insure that it is benign.
Polyps can be present in the uterus without any abnormal uterine bleeding. Therefore, it is not uncommon for polyps to be an incidental finding during an investigation for infertility. One of the common diagnostic tests for infertility is a hysterosalpingogram (HSG), which is an x-ray of the uterus and fallopian tubes.
Do Endometrial Polyps Affect Fertility?
Endometrial polyps have been found to be associated with infertility. There is at least one good study that revealed that removal of the polyp increases the chances of conceiving. The study found that when a polyp was removed, the pregnancy rate was 63%. However, if the polyp was not removed at hysteroscopy, the pregnancy rate was only 28%.
Another study found that the most common area in the uterus for an endometrial polyp to be found was on the posterior uterine wall. Interestingly, polyps that were found in the cornual portion of the uterus (the area of the opening of the fallopian tubes into the uterus) were associated with a higher chance of pregnancy when these polyps were removed compared to removing polyps from other locations within the uterus. This suggests that polyps in this location are more likely to be associated with difficulty in conceiving. However, the exact mechanism is unknown.
It has been speculated that a endometrial polyp may cause irritation of the lining of the uterus interfering with implantation of an embryo. These polyps can interfere with implantation, effectively preventing an embryo from attaching to the uterine wall. It is common for polyps to induce a chronic inflammatory response within the uterus, as the body mounts a reaction to try to destroy the polyp. This may be the mechanism by which polyps interfere with the establishment of a pregnancy.
It is appropriate that the uterus be evaluated during the fertility investigation. If an abnormality in the uterus is discovered, it is recommended that the woman should undergo a hysteroscopy to remove the abnormality. Hysteroscopy is preferable to a “blind” D&C.