Don’t forget about the early blastocyst: up to 30% may be euploid and available for transfer

Don’t forget about the early blastocyst: up to 30% may be euploid and available for transfer
Preimplantation genetic screening (PGS) is an important management tool for many patients pursuing IVF. While trophectoderm biopsy of expanded and hatching blastocysts is standard practice, not all blastocysts make it to either stage. By definition, an early blastocyst has a cavity that occupies less than 50% of the volume of the embryo (1). When the trophectoderm is not well delineated from the inner cell mass, attempting a biopsy can prove to be futile. However, in some cases, delineation may be sufficient for trophectoderm biopsy and may help to increase euploid yield.
Source: fertstert.org