Leptin is not involved in the pathophysiology of endometriosis-related infertility.

Objective: Changes in peritoneal fluid (PF) composition may affect fertilization as well as early embryonic development. Leptin, an adipocyte hormone, has been shown to act as a link between adipose tissue and the reproductive system. Therefore, we decided to assess peritoneal and serum leptin levels in infertile endometriotic patients.

Patients: Seventy-two women were studied, including 30 fertile and 18 infertile women with ovarian endometriotic cysts and, as a reference group, 24 patients with unexplained infertility.

Results: No significant difference in the peritoneal and leptin levels was found between the studied groups. Significantly higher PF leptin concentration was observed in patients with stages III and IV of endometriosis as compared to those with minimal stage of the disease. In fertile patients with endometriosis a positive correlation has been found between PF and serum leptin concentrations.

Conclusions: No differences in peritoneal or serum leptin levels between infertile and fertile women with endometriosis suggest that this cytokine is not involved in pathophysiology of endometriosis-related infertility.