Introduction: Composition of follicular fluid is also regarded to be linked to quality of oocytes, fertilization and quality of the embryo. The aim of this study was to investigate the concentration of IL-18 and IL18BP in follicular fluid (FF) in a homogeneous group of women with sterility caused by "tubal factor" subjected to in vitro fertilization (IVF) and the relation between concentrate of this cytokine and IVF outcome.
Materials/methods: The study group consisted of 83 non-smoking women aged 30.9 ± 3.2 (23.0-43.0) with confirmed (hysterosalpingography and/or laparoscopy) bilateral complete tubal impermeability. Follicular fluid levels of IL-18 and IL18BP were evaluated in 83 patients undergoing in vitro fertilization (IVF). Ovarian hormonal stimulation was conducted according to a GnRH antagonist protocol. The measurement of IL-18 and IL18BP in follicular fluid was done using the ELISA method.
Results: The mean follicular levels of IL-18 and IL18BP were 468.5 ± 357.4 pg/ml and 8611.3 ± 534 pg/ml. The biochemical pregnancy rate was 39.7% (33/83); 22 women became clinically pregnant (26.5%). The implantation rate was 26.7% (36/135). No significant correlation was found between follicular concentrations of IL-18 and age of the patients (r = 0.13 p>0.05), number of metaphase II oocytes collected (r = -0.11 p>0.05), number of 3-day embryos (r = -0.157 p>0.05), biochemical pregnancies (r = 0.03 p>0.05), or clinical pregnancies (r = -0.06 p>0.05). Also there was no significant correlation between IL18BP and age of the patients (r = 0.21 p>0.05), number of metaphase II oocytes collected (r = 0.08 p>0.05), number of 3-day embryos (r = -0.19 p>0.05), biochemical pregnancies (r = 0.11 p>0.05) and clinical pregnancies (r = -0.34 p>0.05).
Conclusion: IL-18 and IL18BP are detectable in follicular fluid but do not determine IVF outcome in women with "tubal factor". IL-18 and IL18BP are not promising prognostic markers for IVF success in this subgroup of patients.