Uterine Polyps: Removal for Infertility and Pregnancy?
Uterine polyps are a common finding in women. Let me explain how to find them, remove them and their impact on your fertility.
What are uterine (endometrial) polyps?
Uterine polyps are one of the most common abnormalities found in women with fertility problems. Do they cause infertility? Should you have surgery to remove polyps?
The uterus has three layers:
- The outer surface
- The muscle layer
- The uterine lining which is called endometrium
Polyps are growths that arise from the endometrium. Nobody really knows why polyps occur in some women. Like normal endometrium estrogen can make polyps grow larger.
What are the symptoms of polyps?
In some cases, polyps cause women to have abnormal vaginal bleeding. They may have periods that are heavier or longer or they may have bleeding in between periods. Most women who have polyps however do not have any signs or symptoms. There is evidence that polyps are more common in women with fertility problems.
Some studies have found polyps in 6% of women starting treatment with IVF. Another study found polyps in 16% of women with multiple failed IVF cycles.
How do polyps cause fertility problems?
We really don't know. There may be several different ways that polyps cause fertility problems. There are three factors that seem to be important:
- The size of the polyp. The larger the polyp the greater its impact on fertility.
- The location of the polyp. For example some polyps may block the opening of the fallopian tube and prevent sperm from getting into the tubes to fertilize the eggs.
- The number of polyps. The more polyps you have the greater the chance for problems.
How can you find polyps?
Polyps are sometimes found during a regular ultrasound. But most of the time, ultrasound will miss polyps. This is because the polyps can blend in with the normal endometrium.
One way to look for polyps is with a saline ultrasound. The doctor places a catheter into the uterine cavity and injects salt water. The fluid opens up the walls of the cavity. This isolates the polyp making it easier to see.
A second option is with a hysterosalpingogram or HSG. In this procedure the fluid used is contrast that shows up on x-ray. If you have a growth inside the uterine cavity, it will show up because the contrast fluid flows around it.
The third technique is hysteroscopy. This is when we put a telescope inside the uterine cavity to look directly.
How to treat polyps
Hysteroscopy is also the way that polyps are treated. With smaller polyps they can be grasped and then pulled off of the uterine lining.
With larger polyps electrical instruments can be used to resect the polyps and strips. Once a polyp is completely removed it will not return but new polyps can grow at a later time.
Will removing polyps improve fertility?
It is difficult to do studies on the effectiveness of polyp removal. To prove that polyp removal is effective you would like to have two groups of women. One group would undergo polyp removal and one group would not. These are difficult studies to do since nobody wants to participate in a study in which a potential abnormality is not treated.
It is also difficult because you would like the two groups to be identical in terms of the size, number and location of polyps. This is really difficult to accomplish.
Given these limitations, we do have studies that polyp removal can help. Some studies looked at how often women with infertility became pregnant after polyp removal and saw more women become pregnant within a year compared to women who did not have polyps. Some better studies were done in women who were going to be treated with intrauterine insemination. They split women with polyps into two groups: one group had polyp removal and one didn't.
The two studies found that the pregnancy rates were higher in women who had polyp removal.
There have been several studies on polyp removal in women undergoing IVF. The evidence here is a bit mixed. Some studies showed a benefit to polyp removal but some studies did not. Despite the lack of definite proof however most IVF experts will recommend polyp removal to their patients before embryo transfer.