Table 7_Impact of euploid blastocyst developmental stage and morphological grading on pregnancy outcomes in young recurrent pregnancy loss patients: association with parental chromosomal status.docx

ObjectiveThis study investigated the impact of blastocyst developmental stage and morphological grading on pregnancy outcomes following single euploid frozen-thawed blastocyst transfer (SE-FBT) in young patients with recurrent pregnancy loss (RPL) and balanced chromosomal translocations (BCTs), compared to patients with normal karyotypes.
MethodsA retrospective cohort analysis was performed on 449 SE-FBT cycles (2017–2023), comprising 177 cycles from patients with BCT and 272 cycles from patients with normal karyotypes. Blastocysts were categorized according to their developmental stage (day 5 [D5] versus day 6 [D6]) and morphological grading (good versus poor). Multivariable logistic regression models were used to adjust for potential confounders.
ResultsAmong BCT carriers, D5 blastocysts exhibited significantly higher clinical pregnancy rates (CPR: 83.33% vs. 62.86%; adjusted odds ratio [aOR] = 2.90, P = 0.005) and live birth rates (LBR: 75.00% vs. 51.43%; aOR = 2.6, P = 0.010) compared to D6 blastocysts, whereas morphological grading showed no significant association after adjustment. Among normokaryotypic patients, however, blastocyst morphological grading was the primary prognostic factor, with good-grade blastocysts yielding superior CPR (74.13% vs. 54.26%, aOR = 2.46, P = 0.001) and LBR (56.64% vs. 40.31%, aOR = 1.76, P = 0.039), while developmental stage had no significant effect.
ConclusionsThese findings suggest that the developmental stage of the blastocyst is the primary determinant of successful outcomes in BCT-associated RPL, whereas embryo morphological grading predominantly influences pregnancy outcomes in RPL patients with normal karyotypes. These results highlight the importance of personalized embryo selection strategies based on parental chromosomal status and embryological characteristics to optimize reproductive outcomes in distinct RPL.

研究目的：本研究旨在探讨复发性流产（recurrent pregnancy loss, RPL）合并染色体平衡易位（balanced chromosomal translocations, BCTs）的年轻患者，在接受单整倍体冻融囊胚移植（single euploid frozen-thawed blastocyst transfer, SE-FBT）后，囊胚发育阶段及形态学评分对妊娠结局的影响，并与核型正常患者进行对比。
研究方法：本研究对2017年至2023年间的449例SE-FBT移植周期进行回顾性队列分析，其中包含177例BCT患者周期及272例核型正常患者周期。根据发育阶段（第5天[D5]与第6天[D6]）及形态学评分（优质与劣质）对囊胚进行分类。采用多变量logistic回归模型校正潜在混杂因素。
研究结果：在BCT携带者中，与D6期囊胚相比，D5期囊胚的临床妊娠率（clinical pregnancy rates, CPR：83.33% vs. 62.86%；校正后优势比[adjusted odds ratio, aOR]=2.90，P=0.005）与活产率（live birth rates, LBR：75.00% vs. 51.43%；aOR=2.6，P=0.010）均显著更高；校正后形态学评分未显示出显著关联。但在核型正常患者中，囊胚形态学评分是主要的预后因素：优质囊胚的CPR（74.13% vs. 54.26%；aOR=2.46，P=0.001）与LBR（56.64% vs. 40.31%；aOR=1.76，P=0.039）均更优，而发育阶段无显著影响。
研究结论：本研究结果表明，囊胚发育阶段是BCT相关RPL患者妊娠成功的主要决定因素，而胚胎形态学评分则主要影响核型正常的RPL患者的妊娠结局。上述结果凸显了基于父母染色体核型及胚胎学特征制定个性化胚胎选择策略的重要性，以优化不同类型RPL患者的生殖结局。