**6. Conclusion**

In conclusion, PGs play a substantial role in the physiological and pathological processes in the reproductive system. PGs are known to be involved in the initiation of the phsysiological implantation and decidualization. Also, COX-2 and PGE2 were seen to be overexpressed in several pathological circumstances as different types of cancers and other inflammation related diseases.

There is no doubt that PGE2 is implicated in the aetiopathogenesis of endometriosis and contributes to the development and maintenance of the disease. The elevated levels of PGs found in the peritoneal fluid from patients with endometriosis are mainly produced by peritoneal macrophages and endometriotic tissues. As well, the peritoneal estrogens, proinflammatory and pro-angiogenic molecules contribute to elevate the expression of COX-2 and consequently the levels of PGE2 in endometriosis patients. The pelvic pain associated to endometriosis has also been demonstrated to be mediated through the action of PGE2 and inhibition of PG production usually resolves the pain.

Given these data, further investigations should focus on how to inhibit the production of PGs in endometriosis, to control the pain and the development of the pathology.
