Oocytes [328] from 874 studied were found suitable for counting chromosomes. Oocytes [263] (80.18%) had a normal chromosome number, while aneuploidy was observed in 18.3% of oocytes (61). Among them 46 (14.02%) were hypoploidy and 14 (4.26%) were hyperploid with 21 chromosomes and over. Structural chromosome aberrations were found in 24 oocytes (7.31%).