Wang Junqiang, Yang Zexing, Chen Ying, Gao Fengchen, Zhao Wenxiu, Cao Shuxuan, Li Yixi, He Limei
School of Public Health, Kunming Medical University, Kunming, China.
Department of Reproductive Genetics, The First Affiliated Hospital of Kunming Medical University, Kunming, China.
Front Endocrinol (Lausanne). 2025 Jun 25;16:1551530. doi: 10.3389/fendo.2025.1551530. eCollection 2025.
To identify the determinants influencing clinical pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles.
A retrospective analysis was conducted on patients who underwent FET at the Department of Reproductive Genetics, The First Affiliated Hospital of Kunming Medical University, between January 2018 and December 2023. A total of 7,302 FET cycles were included and categorized into two groups based on clinical pregnancy outcomes: the clinical pregnancy group (n = 3,365) and the non-clinical pregnancy group (n = 3,937). Baseline characteristics were compared between groups. A random forest algorithm was applied to rank the importance of variables, followed by dimensionality reduction using a sliding window sequential forward selection (SWSFS) method. The top-ranked predictors with the lowest average out-of-bag (OOB) error rates were incorporated into a multivariate logistic regression model to determine independent predictors of clinical pregnancy in FET cycles.
The overall clinical pregnancy rate (CPR) was 46.08%. The CPR was significantly higher in blastocyst transfers (61.14%) compared to cleavage-stage embryo transfers (34.13%) (χ² = 528.973, < 0.01). The random forest model identified seven variables with the highest predictive value: female age, number of high-quality blastocysts, anti-Müllerian hormone (AMH) level, embryo stage at transfer, endometrial thickness on the day of transfer, number of high-quality cleavage-stage embryos, and pre-transfer endometrial thickness. Multivariate logistic regression analysis demonstrated that younger female age (OR: 0.93; 95% CI: 0.92-0.94), greater number of high-quality blastocysts (OR: 1.67; 95% CI: 1.49-1.88), higher AMH levels (OR: 1.03; 95% CI: 1.01-1.05), blastocyst transfer (OR: 2.31; 95% CI: 1.85-2.88), increased endometrial thickness on transfer day (OR: 1.10; 95% CI: 1.05-1.15), more high-quality cleavage-stage embryos (OR: 1.74; 95% CI: 1.59-1.92), and greater pre-transfer endometrial thickness (OR: 1.04; 95% CI: 1.00-1.09) were all independently associated with higher clinical pregnancy rates.
Female age, number of high-quality blastocysts, AMH levels, embryo stage at transfer, endometrial thickness on the day of transfer, number of high-quality cleavage-stage embryos, and pre-transfer endometrial thickness are significant predictors of clinical pregnancy outcomes in FET cycles. These findings may guide individualized embryo transfer strategies to optimize reproductive success.
确定影响冻融胚胎移植（FET）周期临床妊娠结局的决定因素。
对2018年1月至2023年12月在昆明医科大学第一附属医院生殖遗传科接受FET的患者进行回顾性分析。共纳入7302个FET周期，并根据临床妊娠结局分为两组：临床妊娠组（n = 3365）和非临床妊娠组（n = 3937）。比较两组的基线特征。应用随机森林算法对变量的重要性进行排序，随后使用滑动窗口顺序向前选择（SWSFS）方法进行降维。将平均袋外（OOB）错误率最低的排名靠前的预测因素纳入多变量逻辑回归模型，以确定FET周期临床妊娠的独立预测因素。
总体临床妊娠率（CPR）为46.08%。与卵裂期胚胎移植（34.13%）相比，囊胚移植的CPR显著更高（61.14%）（χ² = 528.973，P < 0.01）。随机森林模型确定了七个预测价值最高的变量：女性年龄、高质量囊胚数量、抗苗勒管激素（AMH）水平、移植时的胚胎阶段、移植当天的子宫内膜厚度、高质量卵裂期胚胎数量以及移植前子宫内膜厚度。多变量逻辑回归分析表明，较年轻的女性年龄（OR：0.93；95%CI：0.92 - 0.94）、更多的高质量囊胚数量（OR：1.67；95%CI：1.49 - 1.88）、更高的AMH水平（OR：1.03；95%CI：1.01 - 1.05）、囊胚移植（OR：2.31；95%CI：1.85 - 2.88）、移植当天子宫内膜厚度增加（OR：1.10；95%CI：1.05 - 1.15）、更多的高质量卵裂期胚胎（OR：1.74；95%CI：1.59 - 1.92）以及移植前子宫内膜厚度增加（OR：1.04；95%CI：1.00 - 1.09）均与更高的临床妊娠率独立相关。
女性年龄、高质量囊胚数量、AMH水平、移植时的胚胎阶段、移植当天的子宫内膜厚度、高质量卵裂期胚胎数量以及移植前子宫内膜厚度是FET周期临床妊娠结局的重要预测因素。这些发现可能指导个体化胚胎移植策略以优化生殖成功率。
