P-251 Cumulus cell analysis as a non-invasive oocyte selection strategy to reduce the number of oocytes/embryos cultured and increase pregnancy rates

Study question: Can non-invasive gene expression analysis of cumulus cells (CC) improve efficiency in ART by prioritizing oocytes for further culture and fresh single embryo transfer? Summary answer: CC analysis can be used for the selective processing of oocytes. This may reduce culture work and improve the outcome in ICSI elective SETs (eSET). What is known already: In an interventional, blinded, prospective cohort study (Van Vaerenbergh et al. 2021), 113 patients underwent a fresh Day3 eSET with embryos ranked and transferred based on morphology and CC gene expression (Aurora Test), while 520 control patients underwent a Day3 eSET without the Aurora Test. This resulted in a significant higher clinical pregnancy of 61% in the patients with eSET based on CC ranking applied on good morphology embryos, compared to 29% in the controls with eSET based on embryo morphology only. Live birth rate was also significantly increased, while time-to-pregnancy was significantly reduced with 3 transfer cycles. Study design, size, duration: In a retrospective analysis, in a subset of patients with at least 6 growing follicles and at least five 2PN oocytes (n=80), it was investigated whether the Aurora Test, used to select transferrable Day3-embryos, could also be applied to select oocytes on Day0/1. The effect of processing only the three highest ranked oocytes (based on the Aurora Test) on embryo development and clinical pregnancy was studied compared to processing all oocytes. Participants/materials, setting, methods: Patients included in this single centre study had their first or second GnRH-antagonist ICSI cycle, were younger than 40y, had normal BMI, were stimulated with HP-hMG and scheduled for Day3 eSET. Two-sided statistical analysis (p