Objective: Our aim was to design simple method for quantitative evaluation of oocyte and embryo morphology in in vitro fertilization (IVF) programme efforting of embryo implantation prediction to be able to set the optimal number of embryos for transfer for given specific case. This study deals with zona pellucida (ZP) – the one interesting and for oocyte unique structure. The work is the part of comprehensive research of oocyte, zygote and embryo morphology. Design: Prospektive study. Setting: Center of Assisted Reproduction, Department of Gynaecology and Obstetrics, Medical Faculty of Charles University, Pilsen. Methods: The study includes analysis of 66 microphotography pictures of oocytes, zygotes and embryos of patients who were treated by IVF on our department between September and December 2000. The microphotographs were taken by digital microphotographic system. Analysis of zona pellucida parameters was conducted by image analysis software called AnalySIS, Soft Imaging System GmbH. Results: It was found out the average widht of the zona pellucida 18.4 mm ± 2.1 mm, the minimum width was 12.3 mm a maximum 23.1 mm. Conclusion: There was found significant narrower zona pellucida in women who conceived in this IVF cycle then in the women who did not.

        Key words: zona pellucida, oocyte, in vitro fertilization, infertility