Giant oocytes in human in vitro fertilization treatments

Purpose Giant oocytes are potential sources of chromosomal abnormalities and should thus never be used in in vitro fertilization and embryo transfer (IVF-ET) procedures. The presence of giant oocytes may indicate the efficiency of the ovarian stimulation and can refer to the quality of sibling oocytes. Methods IVF cycles performed between January 2008 and November 2013 ( n = 1521) were divided into two groups: Giant Oocyte Group (GO Group) contained cycles with at least one giant oocyte in the cohort of the retrieved oocytes ( n = 37), Normal Group contained cycles with no giant oocytes ( n = 1484). In the second part of the study, cycles from GO Group and Normal Group were matched according to patient age, number of retrieved oocytes and stimulation protocol, and thus 30 pairs were formed. Clinical and embryological data were analyzed. Results The incidence of giant oocytes was 0.3 %. The average patient age was lower (33.5 ± 3.9 vs. 35.3 ± 4.9, p = 0.02); estradiol (E 2 ) levels (1954 ± 903 vs. 1488 ± 909 pg/l, p