Preimplantation development analysis of aneuploid embryos with different chromosomal abnormalities

Area of Science:

• Reproductive Biology
• Genetics
• Embryology

Background:

• Aneuploidy, an abnormal chromosome number, impacts embryonic development.
• Morphokinetic parameters observed via time-lapse monitoring offer potential for non-invasive embryo assessment.
• Understanding how chromosomal abnormalities affect embryo development is crucial for improving selection strategies.

Purpose of the Study:

• To investigate the impact of various chromosomal abnormalities on embryonic morphokinetic patterns.
• To identify specific morphokinetic parameters indicative of aneuploidy.
• To assess the potential for non-invasive selection of euploid embryos based on morphokinetic data.

Main Methods:

• Analysis of 939 time-lapse preimplantation genetic testing cycles involving 2876 biopsied blastocysts.
• Utilized intracytoplasmic sperm injection, blastocyst culture, trophectoderm biopsy, time-lapse monitoring, and next-generation sequencing.
• Employed multilevel mixed-effects logistic regression to analyze morphokinetic parameters and predict ploidy status, adjusting for patient and cycle factors.

Main Results:

• Six key morphokinetic parameters (t5, t8, tSB, tB, t5-t2, tB-tSB) significantly predicted euploid versus aneuploid embryos.
• Embryos with chromosome fragment deletions or duplications showed prolonged morphokinetic parameters, particularly at later cleavage and blastocyst stages.
• Monosomic embryos exhibited prolonged blastocyst stage parameters, and specific deletions (chromosome 20 or 22) caused significant delays across multiple stages.

Conclusions:

• Different chromosomal abnormalities distinctly affect embryonic morphokinetic parameters.
• Significant delays in morphokinetic parameters are observed in embryos with fragment mutations and monosomy.
• These findings provide insights into aneuploid embryo development and support non-invasive embryo selection methods.