Abstract
PURPOSE: To characterize the morphokinetic parameters of embryos derived from IVM oocytes and to identify critical factors associated with blastocyst formation potential and chromosomal euploidy. METHODS: This retrospective study reviewed 99 523 fresh cycles between January 2019 and March 2025. From this population, 3,202 PGT cycles were initially screened. A total of 353 cycles involving IVM oocytes were then selected, and ultimately, 83 IVM-derived embryos from 59 cycles were included. RESULTS: The non-formation group exhibited delays in t2, t9, and several developmental intervals, including S2, t9-t7, t9-t8 (p < 0.05). Multivariate logistic regression analysis identified S2 (p = 0.021) and t9-t7 (p = 0.042) as independent factors associated with blastocyst formation. Subsequently, ROC analysis showed that both S2 ≤ 1.95 h (AUC = 0.620, p = 0.036) and t9-t7 ≤ 24.35 h (AUC = 0.672, p < 0.001) exhibited predictive power for blastocyst formation. Furthermore, shorter tSB-t9 and tB-t9 were associated with euploidy in IVM-derived blastocysts (p = 0.025 and p = 0.014, respectively), with tSB-t9 emerging as an independent factor associated with chromosomal normality (p = 0.044) in multivariate analysis. CONCLUSIONS: This study presents the morphokinetic characteristics and identifies key markers for blastocyst formation and chromosomal euploidy in IVM-derived embryos.