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-alpha (TNF-alpha) 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, P < 0.001, Student's t-test). There was no significant difference in TNF-alpha 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.