Morphokinetic parameters in chromosomal translocation carriers undergoing preimplantation genetic testing

Area of Science:

• Reproductive Medicine
• Genetics
• Embryology

Background:

• Translocation carriers face challenges in achieving successful pregnancies due to the risk of unbalanced embryos.
• Preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) is crucial for these patients.
• Identifying unbalanced embryos non-invasively could improve PGT-SR outcomes.

Purpose of the Study:

• To investigate if embryo morphokinetic parameters derived from time-lapse imaging can distinguish between balanced and unbalanced embryos in translocation carriers undergoing PGT-SR.
• To assess the predictive performance of existing aneuploidy models in this specific patient population.

Main Methods:

• Retrospective analysis of 105 PGT-SR cycles in 67 translocation carriers without concurrent PGT-A.
• Comparison of morphokinetic parameters and abnormal cellular events between balanced and unbalanced embryos using time-lapse imaging.
• Evaluation of a previously published aneuploidy prediction model.

Main Results:

• While some morphokinetic parameters (t5, t9+, cc2, s2, t5-t2) and cellular events (multinucleation, abnormal division, cell exclusion) showed significant differences between balanced and unbalanced embryos, they lacked predictive accuracy.
• A previously validated morphokinetic prediction model for aneuploidy did not effectively classify embryos in this cohort.
• No morphokinetic parameter reliably identified the chromosomal status of embryos in translocation carriers.

Conclusions:

• Embryo morphokinetics and time-lapse imaging are not suitable diagnostic tools for determining chromosomal status in embryos from translocation carriers.
• Current morphokinetic parameters cannot reliably differentiate balanced from unbalanced embryos in this population, necessitating continued reliance on genetic testing.