Optimal timing for blastomere biopsy of 8-cell embryos for preimplantation genetic diagnosis

AbstractSTUDY QUESTIONWhat is the optimal timing for blastomere biopsy during the 8-cell stage, at which embryos will have the best implantation potential?SUMMARY ANSWERFast-cleaving embryos that are biopsied during the last quarter (Q4) of the 8-cell stage and are less affected by the biopsy procedure, and their implantation potential is better than that of embryos biopsied earlier during the 8-cell stage (Q1 –Q3).WHAT IS KNOWN ALREADYBlastomer biopsy from cleavage-stage embryos is usually performed on the morning of Day 3 when the embryos are at the 6- to 8-cell stage and is still the preferred biopsy method for preimplantation genetic diagnosis (PGD) for monogentic disorders or chromosomal translocations. Human embryos usually remain at the 8-cell stage for a relatively long ‘arrest phase’ in which cells grow, duplicate their DNA and synthesize various proteins in preparation for the subsequent division.STUDY DESIGN, SIZE, DURATIONThis is a retrospective cohort study. The study group (195 embryos) included all 8-cell stage embryos that underwent blastomere biopsy for PGD for monogenetic disorders and chromosomal translocations in our unit between 2012 –2014 and cultured in the EmbryoScope until transfer. The control group (115 embryos) included all embryos that underwent intracytoplasmic sperm injection without a biopsy during the same period.PARTICIPANTS/MATERIALS, SETTING, METHODSThe 8-cell stage was divided into four quarters: the first 5 h post-t8 (Q1), 5 –10...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research