Objective: The aim of our study was to evaluate the role of follicular fluid pH as the marker of quality of the human oocyte in the IVF treatment efforting to predict and to enhance the effect of IVF treatment: oocyte quality, fertilization rate, cleavage rate, implantation rate. Design: Prospektive study. Setting: Center of assisted reproduction, Department of Gynaecology and Obstetrics, Medical Faculty of Charles University, Pilsen. Methods: The pH of the follicular fluid was mesured in 147 IVF cycles. The oocyte quality was evaluated according to the oocyte-cumulus-cells complex morphology during the ovum pick up, according to fertilization rate, number of recovered oocytes and recovery rate. Results: The lower pH of the follicular fluid correlated with significant higher occurence of the cycles with more then half of oocyte-cumulus complexes with normal mature morphology (P = 0.026) and correlated with significant higher occurence of cycles with fertilization rate more then 10% (P = 0.033). Conclusion: There was found a lower pH of the follicular fluid in the IVF cycles where the quality of oocytes was higher.

        Key words: pH, follicular fluid, oocyte quality, in vitro fertilization, infertility