Preimplantation genetic testing for aneuploidy: predictive embryonic factors

Area of Science:

• Reproductive Science
• Genetics
• Embryology

Background:

• Preimplantation genetic testing for aneuploidy (PGT-A) is crucial for assessing embryo viability.
• Blastocyst quality, biopsy timing, and hatching status are potential factors influencing PGT-A success.

Purpose of the Study:

• To investigate the impact of blastocyst quality, biopsy day, and hatching status on euploidy rates and embryo survival after freezing in PGT-A cycles.

Main Methods:

• Retrospective analysis of 6130 biopsied blastocysts from 1849 PGT-A cycles.
• Embryos categorized by Gardner's quality score, biopsy day (5 or 6), and hatching status (fully hatched vs. non-fully hatched).
• Statistical assessment of the relationship between these factors and euploidy/survival rates.

Main Results:

• Excellent quality embryos (AA) had higher euploidy rates (52.69%) than good (39.69%) or poor (26.21%) quality embryos.
• Day 5 biopsied embryos showed higher euploidy (39.98%) and survival (93.71%) than day 6 embryos (34.80%, 83.69%).
• Fully hatched blastocysts (FHB) had poorer survival (78.61%) than non-fully hatched (nFHB) (93.52%).

Conclusions:

• Higher blastocyst quality and earlier biopsy (day 5) are associated with increased euploidy rates.
• Poor quality, day 6 biopsy, and fully hatched blastocysts exhibit significantly lower survival rates after biopsy and vitrification.