PGS on Blastocysts From Vitrified and Fresh Oocytes

Increase the Number of Blastocyst to Biopsy for Preimplantation Genetic Testing

aneuploidy, next generation sequencing, oocyte vitrification, preimplantation genetic diagnosis, preimplantation genetic screening

Oocyte accumulation by vitrification is a valid strategy to increase the number of available embryos for biopsy and the number of viable euploid embryos to transfer after preimplantation genetic testing.

In the present study, the investigators considered the hypothesis to accumulate vitrified oocytes with a view to increasing the number of oocytes for micro-injection and consequently the number of blastocyst to diagnose for patients with normal ovarian reserve and candidate for PGT. The partecipants were proposed to undergo several cycles of ovarian stimulation. In the first cycles, mature (metaphase II) oocytes were vitrified and consequently accumulated. In the last cycle, the freshly produced mature oocytes and the previously accumulated ones were micro-injected together with the same partner's semen sample. PGT was performed on blastocysts produced from the two sources of oocytes. The comprehensive chromosomal analysis of biopsied trophectoderm cells was performed using NGS technology. The number of available euploid blastocyst and the proportion of euploid/aneuploidy embryos from fresh and vitrified/warmed oocytes were compared. In conclusion the investigators evaluated the efficacy of oocyte accumulation by vitrification in increasing the number of available embryos for biopsy and the number of viable euploid embryos to transfer after PGT.

Italy