Endometriosis is known to have a profoundly significant negative effect on fertility.  Normal natural pregnancy rates are in the range of 0.15 to 0.20 per month and decrease with age, but women with endometriosis tend to have a lower monthly rate of about 0.02–0.1 per month.  Conversely, infertile women are 6 to 8 times more likely to have endometriosis than fertile women. 

Why does endometriosis cause infertility?   The inflammation associated with endometriosis can have a multi-factorial negative influence on fertility including the following reasons.

  • Painful symptoms decrease libido
  • “Pelvic factor”: Scarring and adhesions can block tubes, hide ovaries, and limit their proximity
  • Decrease the “quality” of oocytes
  • Alters endometrial “receptivity”
  • Immunologic Implantation Dysfunction (IID)

Regarding IID, multiple studies corroborate that the pathology of endometriosis is at least in part attributable to an abnormal maternal immune environment.  This is suggested by the fact that endometriosis is associated with the co-presence of multiple immune-mediated diseases such as multiple sclerosis, rheumatoid arthritis, systemic lupus, Sjögren’s syndrome, Hashimoto’s thyroiditis, and fibromyalgia. Based on multiple streams of  evidence demonstrating the abnormal modulation of immune factors contributing to endometriotic lesion implantation and survival, it becomes a question as to whether to classify endometriosis as an inflammatory condition or an autoimmune disorder (1).


  1. Ahn, Soo Hyun et al. “Pathophysiology and Immune Dysfunction in Endometriosis.” BioMed research international vol. 2015 (2015): 795976. doi:10.1155/2015/795976