Received December 09, 2024
Accepted September 02, 2025

Objective: To evaluate the relationship between time-lapse (TL) imaging parameters and the ploidy of human blastocysts. Methods: This observational study retrospectively analyzes time-lapse images from 84 blastocysts tested for aneuploidies, focusing on morphokinetic evaluation based on cell division (st2, t2, t3, t4, t5, t8, tSC) and blastocyst formation parameters (tSB, tB). Results: Among the TL parameters, t5, t2-st2, cc3 (t5-t3), t5-t2, s3 (t8-t5), and tB-tSB showed a significant association with ploidy, being shorter for euploid blastocysts. The respective median times/intervals for euploid and aneuploid embryos were as follows: t5, 46.5 vs. 49.6 (p=0.015); t2-st2, 2.5 vs. 2.25 (p=0.0236); cc3, 11.7 vs. 13.3 (p=0.046); t5-t2, 22.1 vs. 24.4 (p=0.0185); s3, 10.9 vs. 3.3 (p=0.019); and tB-tSB, 7.6 vs. 9.9 (p=0.0084). ROC curves identified a moderate predictive ability of the parameters to discern euploid embryos. Additionally, initial cytoplasmic movements prior to the first cell cleavage were noted; pattern 1 (vibration-like movements), pattern 2 (circular wave movements), or pattern 0 (the absence of detectable movements) were not significantly correlated with ploidy. Conclusions: Euploid blastocysts reach certain cell division stages (t5, t5-t3, t5-t2, t8-t5) and blastocyst formation stages (tB-tSB) more quickly than aneuploid ones. If further studies confirm this, our results should serve as criteria for selecting embryos to be biopsied, potentially avoiding the procedure when euploidy can be predicted from morphokinetic features.