Can expelled cells/debris from a developing embryo be used for PGT?

Area of Science:

• Reproductive Medicine
• Genetics
• Embryology

Background:

• Preimplantation genetic testing (PGT) utilizes polymerase chain reaction (PCR) for DNA amplification from embryo biopsies.
• Embryo biopsy for PGT may negatively impact implantation potential.
• Human embryos release cell debris during later culture stages.

Purpose of the Study:

• To evaluate the feasibility of using embryonic cell debris for PGT.
• To determine if cell debris can serve as an alternative to embryo biopsy, thereby mitigating risks to implantation.

Main Methods:

• Analyzed cell debris from hatched blastocysts whose Day-3 biopsies indicated genetic defects.
• Compared molecular genetic results from Day-3 blastomeres, Day-5/6 blastocysts, and their corresponding cell debris.
• Utilized multiplex PCR with microsatellite markers for haplotyping.

Main Results:

• Congruent genetic results were observed in 57.2% (8/14) of embryos when comparing Day-3 biopsy, blastocyst, and cell debris.
• In 42.8% (6/14) of cases, cell debris analysis yielded incomplete diagnoses, although Day-3 and blastocyst results were consistent.
• This suggests cell debris analysis is not always a complete substitute for embryo biopsy.

Conclusions:

• Examining Day-4 cell debris for PGT is a potential alternative to Day-3 blastomere or Day-5 trophectoderm (TE) biopsy.
• This approach may avoid embryo biopsy-related implantation issues.
• In cases of incomplete diagnosis from cell debris, Day-5 TE biopsy remains necessary for definitive genetic results.