Embryo morphokinetics and PGT-A outcomes in recurrent pregnancy loss cases

Recurrent pregnancy loss (RPL) is a clinically important condition in women undergoing assisted reproductive technologies (ART). This study evaluated embryo morphology and morphokinetic parameters using time-lapse monitoring (TLM) and assessed embryo ploidy by preimplantation genetic testing for aneuploidy (PGT-A) in women with RPL compared with unexplained infertility (UEI) controls. A total of 190 patients (100 RPL, 90 UEI) and 1169 embryos (634 RPL, 535 UEI) cultured under TLM were analyzed. Clinical characteristics, embryo morphology, morphokinetics and ploidy status were compared between groups, and logistic regression was used to identify predictors of aneuploidy. The euploidy rate was significantly lower in the RPL group than in controls (43.5% vs. 52.3%, p = 0.018). Group-wise analysis of all embryos revealed differences in selected morphokinetic parameters (t9 and tSC; p < 0.05). However, morphokinetic timing of euploid embryos did not differ between groups, suggesting that accelerated development alone was not associated with chromosomal abnormality. Embryo morphology was the strongest predictor of aneuploidy in both cohorts. Notably, direct uneven cleavage was associated with a 3.4-fold increased risk of aneuploidy specifically in the RPL group. Although embryos from RPL patients showed relatively faster developmental kinetics, morphokinetic speed alone did not predict chromosomal competence. Instead, embryo quality remained the key determinant of aneuploidy, while the association between direct cleavage and aneuploidy highlights the potential clinical value of TLM when combined with PGT-A. These findings support a complementary role for TLM in embryo assessment in RPL patients.