Morphokinetic Markers of Blastocyst Formation and Chromosomal Euploidy in Embryos Derived From In Vitro Maturation Oocytes

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.