There is no certain data that endometriosis affects the ability of a woman to achieve pregnancy if she is being treated with in vitro fertilization. Therefore, it may not be useful to try to treat endometriosis before in vitro fertilization treatment.
Endometriosis occurs in women when the tissue which normally grows on the inside of the uterine cavity, begins to grow outside the uterine cavity. Endometriosis can be found growing in many different areas of the pelvis including the outside of the uterus, the fallopian tubes, the bladder and even on the ovaries. Endometriosis that grows inside of the ovary forms a cyst known as an endometrioma.
There are different scoring systems for evaluating the extent of endometriosis. The most commonly used scoring system has four stages.
- Minimal – Stage 1
- Mild – Stage 2
- Moderate – Stage 3
- Severe – Stage 4
Endometriosis and Infertility
Most studies show a decrease in pregnancy with the more severe stages. There is more controversy about the milder stages. Some studies, for example, do not show a decrease in pregnancy with minimal endometriosis.
The more severe stages of endometriosis are associated with distortion of the pelvic anatomy from scar tissue. Some believe that the presence of endometriosis may also present a hostile environment in the abdomen that interferes with pregnancy.
Endometriosis and IVF
A number of studies have attempted to determine whether the presence of endometriosis is associated with a decrease in in vitro fertilization pregnancy rates. Some of these studies showed an impact but other studies have not. A very interesting study was performed which looked at women who were attempting pregnancy using donated eggs. Eggs from the same women were split into two groups of recipients. One group had endometriosis but the other did not. There was no difference found in the pregnancy rate, miscarriage rate or live birth rate.
Endometrioma and IVF
Some physicians think that if a patient has severe endometriosis with endometriomas, then she will have a worse chance for achieving a pregnancy with in vitro fertilization. However, several studies have not been able to demonstrate this. In fact, in one study doctors compared eggs that were retrieved after inadvertently exposing the eggs to the endometrioma fluid during egg retrieval to eggs from the same patient that were not exposed. No difference was found in either the fertilization rate or the percent of embryos judged to be of good quality.
More recently a study found that surgery to remove endometriomas resulted in IVF patients having less follicles and less eggs retrieved.
Cyst removal resulted in less good quality embryos for transfer in IVF cycles.