Relationship of abnormal vaginal flora, proinflammatory cytokines and idiopathic infertility in women undergoing IVF

OBJECTIVE: To investigate the prevalence of bacterial vaginosis (BV) and abnormal bacterial vaginal flora in an infertile population and correlate with cervical cytokine production and in vitro fertilization (IVF) outcome. STUDY DESIGN: In a blinded study, 331 asymptomatic IVF patients were evaluated for BV, abnormal vaginal flora and cervical cytokine production (interleukin 1 beta [IL-1 beta] and IL-8) on the day of oocyte retrieval. All patients received tetracycline prophylaxis at the time of oocyte retrieval. RESULTS: BV was identified in 4.2% (14/331) of the patients. Patients with idiopathic infertility were more likely to have BV than were women with other causes of infertility (P = .02 vs. male factor, P = .03 vs. tubal factor and P < .01 vs. endometriosis-associated infertility). Patients with abnormal vaginal flora had higher cervical IL-1 beta and IL-8 cytokine levels as compared to patients with normal vaginal flora. IL-1 beta and IL-8 levels in the study subjects correlated highly. No differences were detected in IVF outcome parameters based on the vaginal flora determined at the time of retrieval. CONCLUSION: Abnormal vaginal flora, including that causing BV, is associated with elevated cervical levels of IL-1 beta and IL-8. The induction of proinflammatory cytokines by an altered vaginal ecosystem may be a previously unrecognized cause of idiopathic infertility.