Objective: Shift of indicated invasive examination in prenatal diagnostics towards the earlier phases of pregnancy with preservation of quality of cytogenetic detection. Design: Cytogenetic and molecular-cytogenetic analysis of the chorionic villi after long term culture. Setting: Department of Medical Genetics and Foetal Medicine, Faculty of Medicine, Palacky Uni- versity Olomouc, Faculty Hospital in Olomouc. Methods: Cultivation of fibroblasts developing from chorionic villi after enzymatic or mechanical disintegration and their karyotyping. Using fluorescent in situ hybridisation to identify the most common chromosomal aneuploidies and to determine gonosomes in indicated cases. Results: Testing and optimisation of long term culture method and its routine use. Method was utilised so far in 12 patients and successfulness was 83 %. Additional fluorescent in situ hybridisa- tion was performed in 6 cases. Conclusion: Using long term culture method of chorionic villi as reliable and routine tool in prenatal diagnostics.

        Key words: prenatal diagnosis, CVS, cultivation, FISH