• IL-6;
  • pathophysiology;
  • serum level;
  • TNF-alpha;
  • unexplained infertility

Problem  The aim of this study was to compare the serum levels of interleukin (IL)-6 of women with unexplained infertility with fertile subjects.

Method of study  Serum IL-6, and tumor necrosis factor-α (TNF-α) levels of 45 infertile and 44 fertile women on day 3 of menstrual cycle were assessed and compared for this prospective controlled study.

Results  The mean serum IL-6 level was significantly higher in women with unexplained infertility, compared with fertile women (5.71 ± 1.81 and 4.31 ± 1.79, < 0.001, Student’s t-test). There was no significant difference in TNF-α level among the groups.

Conclusion  Significant difference in serum IL-6 levels between unexplained infertile and fertile women suggests that this cytokine may be involved in pathophysiology of unexplained infertility.