Focused time-lapse analysis reveals novel aspects of human fertilization and suggests new parameters of embryo viability

AbstractSTUDY QUESTIONCan focused application of time-lapse microscopy (TLM) lead to a more detailed map of the morphokinetics of human fertilization, revealing novel or neglected aspects of this process?SUMMARY ANSWERIntensive harnessing of TLM reveals novel or previously poorly characterised phenomena of fertilization, such as a cytoplasmic wave (CW) preceding pronuclear formation and kinetics of pronuclear chromatin polarization, thereby suggesting novel non-invasive biomarkers of embryo quality.WHAT IS KNOWN ALREADYIn recent years, human preimplantation development has been the object of TLM studies with the intent to develop morphokinetic algorithms able to predict blastocyst formation and implantation. Regardless, our appreciation of the morphokinetics of fertilization remains rather scarce, currently including only times of polar body II (PBII) emission, pronuclear appearance and fading, and first cleavage. This is not consistent with the complexity and importance of this process, calling for further TLM studies aimed at describing previously unrecognized or undetected morphokinetic events and identifying novel developmental biomarkers.STUDY DESIGN, SIZE, DURATIONThe study involved a retrospective observation by TLM of the fertilization process in 500 oocytes utilized in consecutive ICSI cycles carried out in 2016. A maximum of five fertilized oocytes per patients were included in the analysis to reduce possible patient-specific biases. Oocytes of patients with differe...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research