Blastocyst culture selects for euploid embryos: comparison of blastomere and trophectoderm biopsies.

Preimplantation genetic diagnosis and screening improves the chances of achieving a viable pregnancy, not only free of undesired single-gene defects but also aneuploidy. In addition, improvements in vitrification provide an efficient means of preserving embryos (blastocysts). By combining trophectoderm biopsy with recent improvements in vitrification methods, only those embryos that have proved themselves viable and potentially more competent are tested. Using array comparative genomic hybridization (aCGH) to assess all 24 chromosomes, aneuploidy rates were compared between day-3 blastomere biopsy and day-5 trophectoderm biopsy. Of those 1603 embryos, 31% were euploid, 62% were aneuploid and 7% not analysable. A significantly larger proportion of embryos were euploid on day-5 biopsy (42%) compared with day-3 biopsy (24%, P<0.0001). The number of euploid embryos per patient was not significantly different. Combining extended culture, trophectoderm biopsy and aneuploidy assessment by aCGH and subsequent vitrification can provide a more efficient means of achieving euploid pregnancies in IVF.

Live birth from previously vitrified oocytes, after trophectoderm biopsy, revitrification, and transfer of a euploid blastocyst.

Our objective is to describe a successful live birth from oocyte vitrification followed by thaw, fertilization, blastocyst culture, trophectoderm biopsy, vitrification, and subsequent thaw. Fifteen mature oocytes were frozen from a patient with uterine factor infertility. Thirteen oocytes survived the thaw, and five underwent trophectoderm biopsy and were refrozen. Three euploid embryos were obtained. A single euploid embryo was transferred in the second thaw cycle to a known recipient leading to the delivery of a normal male infant. This case report is proof of the concept that preimplantation screening and diagnosis is an option for fertility preservation patients.