Uterine Polyps

What is a polyp?

A polyp is a projection of the endometrial glands and stroma. So think about it like the inside layer, that endometrium. You have an actual projection into it, like a little ball. Polyps can be symptomatic or asymptomatic. So the typical symptoms of polyps are intermenstrual bleeding, meaning in between your periods you are having spotting or bleeding. So when I see somebody who's having mid cycle spotting, they might think it's implantation and maybe it is or maybe it's ovulatory. I also always want to rule out a polyp.

How common are polyps?

We know that polyps are the most common structural abnormality of the uterus. Most polyps are benign, but they can be malignant, especially in people who are not having regular periods. You're increasing the risk that this polypoid projection could actually be cancerous. It's estimated that about 10% of people with a uterus have polyps. But to be honest, we don't have that full number because how many people are asymptomatic, might have a polyp, and have never had any imaging inside your uterus, meaning you've never had an HSG test or a saline sonogram. Regular transvaginal ultrasound does not always diagnose them, but it sometimes can. In infertility patients, we see higher rates. Is this because we're looking inside the uterus and in other people we are not? Or is it because it's actually associated with infertility? Honestly, it is probably a combination of both. The prevalence of having a polyp in people who have undergone IVF is gonna be between 11 to 45%. Studies are showing a huge range here and this number is really different. If you break it down and you think about people who have recurrent implantation failure or endometriosis, it does look like polyps are more common in these groups for whatever reason. And we do think that polyps are associated with infertility in some way even if the mechanism may be poorly understood. Some of the different hypotheses, maybe it interferes with sperm actually getting through the uterus. Maybe it impacts embryo implantation through an inflammatory mechanism. That's what most of us think is most common. Further studies have suggested that the location of the polyp may influence pregnancy rate. So if you had polyps in the places of the uterus where embryo is implant, the walls, the lateral walls, then it was more likely that you would not get pregnant with a polyp in place and then have improvement after surgery. And so there probably is some local inflammation or some issue with embryo implantation.

Stay tuned for next week’s blog post about diagnosis and removal of polyps!