Impact of the Endometriomas on the Ovarian Follicles

Ovarian endometriomas may have a direct detrimental impact on ovarian follicles. In this chapter, we review the literature specific to the biological relationship between ovarian endometriomas and oocyte quality and quantity. Anatomically, endometriomas are associated with tubo-ovarian adhesions and deep endometriosis that may negatively affect ovulation and trapping of the oocyte by the tubal fimbriae. Within the ovary, there is iron-mediated oxidative stress and inflammation in endometriosis cyst fluid, peritoneal fluid, and follicular fluid. Abnormalities in granulosa cells, such as increased apoptosis, may result in decreased aromatase activity and estradiol. Stretch of tissues caused by the endometrioma may also trigger signaling cascades that result in the hyperactivation of ovarian follicles, and thus a decrease in ovarian reserve. Together, these biological mechanisms may impair oocyte quantity and quality, and thus fertility, in patients with ovarian endometriomas.