Association between single euploid embryo transfer and pregnancy outcomes in women of advanced maternal age: a propensity score-matched analysis.

Objective: To explore the correlation between preimplantation genetic testing for aneuploidy (PGT-A) and pregnancy, miscarriage, and live birth outcomes among women of advanced maternal age receiving single blastocyst transfer. Methods: In this single-center retrospective cohort study, this study included patients who underwent frozen-thawed embryo transfer at the Reproductive Medicine Center of Yulin Maternal and Child Health Hospital from January 2024 to January 2026. Based on whether preimplantation genetic testing for aneuploidy was performed, the patients were categorized into the PGT-A group and the N-PGT-A group. Propensity scores were calculated via logistic regression and followed by 1:1 nearest-neighbor matching with a caliper width set to 0.2 multiplied by the logist of the propensity score, random matching order, and matching without replacement. Matching variables included maternal age, infertility type, BMI, endometrial preparation protocol, endometrial thickness, endometrial morphology, and serum progesterone levels. After matching, 144 cycles were included in each group. The primary outcome was clinical pregnancy rate, and secondary outcomes included embryo implantation rate, biochemical pregnancy loss rate, early miscarriage rate, and live birth rate. Results: Three stepwise-adjusted logistic regression models were constructed based on the matched cohort, with the N-PGT-A group set as the reference. In the unadjusted model 1, PGT-A was significantly correlated with higher implantation, clinical pregnancy, and live birth rates, as well as lower early miscarriage risk (all P≦0.05), while no significant association was observed between biochemical pregnancy loss. After adjusting for baseline matching covariates in Model 2, PGT-A remained significantly correlated with implantation rate(OR = 2.17, 95%CI:1.31-3.59, P = 0.003) and clinical pregnancy rates (OR = 2.11, 95%CI:1.23-3.64, P = 0.007). No statistically significant associations remained for early miscarriage, biochemical pregnancy loss, or live birth rate (all P > 0.05).In the fully adjusted model 3 incorporating AMH, blastocyst stage, and infertility duration, only the inverse association between PGT-A and early miscarriage rate persisted significantly(OR = 0.31, 95% CI 0.1-0.98, P = 0.047); Implantation rate, clinical pregnancy rate, and live birth rate merely presented marginally favorable non-significant trends (all 0.05< P <0.10), and biochemical pregnancy loss rate remained non-signifiscant between groups. Stratified subgroup analyses by maternal age, paternal age and BMI showed all interaction P >0.05 without effect modification. No significant association between PGT-A and early miscarriage was detected across all stratified subgroups. Conclusion: For female participants aged 35 years or older undergoing single frozen-thawed blastocyst transfer, transfer of PGT-A-screened euploid blastocysts was significantly associated with a decreased risk of early miscarriage. Nevertheless, no statistically significant associations were identified between euploid embryo transfer and clinical pregnancy rate, Biochemical pregnancy loss rate, or live birth rate per single transfer.