GOLDEN EGG. DOES GENETICALLY TESTED OOCYTE CAN INCREASE EFFICIENCY?

Problem statement:There is the possibility of evaluating the aneuploidy status of oocytes with the PGT-A method before vitrification. The chromosomal abnormalities in oocytes reach 60% for advanced maternal age while this figure may be around 30%-40% in donor oocytes.It is possible that 3-4 out of 10 donor oocytes to be taken will have chromosomal anomalies.

Methods: 115 different egg donor stimulated by short antagonist stimulation protocol and after 35 hours post trigger injection 1726 mature oocytes collected. All oocytes` polar bodies biopsied after 2 hours from egg pick up and oocytes vitrified after polar body biopsy. All biopsied polar body samples analyzed by PGT-A techniques. After the PGT-A result all ooctytes had thawing cycle and fertilized by donor sperm. First group included only euploid oocytes and second group included only aneuploid oocytes. After the fertilization all embryos followed up till Day 5 and Day 6 embryo cultured and by trophectoderm biopsy euploidy and aneuploidy rate determinated by PGT-A technique.

Results: Our studies have demonstrated that the aneuploidy ratios obtained from the polar body biopsy and the trophectoderm samples obtained from blastocysts using the same oocytes had a significant similarity with the aneuploidy ratios obtained from the PGT-A test.The post warming survival rate recorded as 95.93% (1650 oocytes survived out of 1720 frozen oocytes). Regarding polar body biopsy result 81,39 % ( 1400 oocytes were euploid out of 1720 oocytes), aneuploidy rate was %18,61. After fertilizatyion by ICSI technique fertilization rate recordes as 91,57% and blastocysts rate recorded 71,88%. Regarding trophectoderm biopsy result by PGT-A was recorded 80,27% euploidy rate. Between euploidy rate of oocyte and embryo correlation recorded as 79,92% of the euploid oocytes were given euploid blastocysts after PGT-A test result.

Conclusion:Donor oocyte aneuploidy testing may use specially when recipients using small batch of oocytes. The PGT-A based testing can be cost effective and more efficient for egg donation.Genetic testing of the oocytes may be beneficial for the selection of the most competent euploid cells.