Allen-Masters Windows, Pouches, Endometriosis & Fertility

I recently had endometriosis surgery. They gave me a video to watch of the pertinent parts of the procedure. The doctor stated I have a Masters Window. What does that mean? How it will affect my trying to get pregnant? H.S.

During your menstrual period, endometrial cells may travel from your uterus into your abdomen. Endometrial cells are present in the abdominal fluid in most women at the time of their period. In women with endometriosis, for some as-yet-unknown reason, the body is just not as effective at clearing these cells from the abdominal cavity, and these cells are more likely to attach and grow.

Allen-Masters windows are pockets or infoldings in the peritoneum, a thin membrane that lines the inside of your abdominal cavity. These pockets tend to trap endometrial cells expelled into the peritoneal cavity during your period. At laparoscopy, a biopsy of the tissue at the base of the Allen-Masters windows frequently shows endometriosis. Many physicians recommend that the peritoneal lining be completely stripped from the Allen-Masters pocket at the time of surgery. The presence of these pockets should in no way effect your fertility. The more important question you did not ask is whether mild or minimal endometriosis lesions on the peritoneal surface are a cause for infertility. The data are confusing at best. While there is certainly a greater risk of finding endometriosis at the time of a laparoscopy for infertility evaluation, this does not necessarily mean that the endometriosis causes infertility. Endometriosis can be the result of a failure to achieve a pregnancy, or it may be due to a genetic or immune factor that is also causing the fertility problems.

The evidence to date, in all but one study, strongly indicates that treating endometriosis does not improve fertility. Unless significant structural abnormalities such as tubal damage, adhesions or ovarian endometriomas are present, most studies suggest that the best approach to fertility is to ignore the endometriosis and to choose the same treatments as would be used for unexplained infertility. Remember that the only way to diagnose endometriosis for sure is by a biopsy (requiring surgery).