P-430 The impact of age on reproductive outcomes of euploid embryos: gamete provider age is irrelevant, but woman’s age at transfer significantly reduces success rates

Abstract

Study question Do the ages of the providers of the gametes or the woman’s age at transfer influence reproductive outcomes in single euploid blastocyst transfers? Summary answer Woman’s age at transfer significantly reduces pregnancy, clinical pregnancy and live birth rates (p < 0.05), while the age of gamete providers has no significant impact What is known already Reproductive success in assisted reproductive technologies (ART) depends on gamete and embryo quality, and uterine receptivity. While advanced maternal age is associated with reduced outcomes, the extent to which this is driven by gamete age or uterine factors remains unclear. Euploid embryos offer a unique opportunity to isolate these effects, as they remove the confounding influence of chromosomal aneuploidy, a known contributor to failed implantation and live birth. However, evidence regarding the relative impact of gamete and recipient age on the success of euploid embryo transfers is still limited, necessitating further investigation. Study design, size, duration This retrospective cohort study analyzed 757 single euploid blastocyst transfers from February-2019 to February-2024. Given that the focus of the study is on the age of the gamete provider and woman’s age at transfer, IVF cycles using both autologous and donor gametes were included. After blastocyst biopsy, PGT-A was performed using next-generation sequencing (NGS). PGT-A was indicated for advanced maternal age or to reduce time-to-pregnancy. Participants/materials, setting, methods Data were stratified by oocyte provider age (<35, 35–37, 38–40, >40 years), sperm provider age (≤40, >40), and woman’s age at transfer (<38, 38–42, 43–45, >45 years). Pregnancy, clinical pregnancy, miscarriage, and live birth rates were compared. For gamete age groups, the impact on post-vitrification survival of biopsied blastocysts was analyzed. Significant results included embryo quality comparisons using the proportion of blastocysts ≥3BB transferred. Chi-square tests with p-value <0.05 were considered significant. Main results and the role of chance The age of the gamete providers did not impact the survival of vitrified biopsied blastocysts, with survival rates consistently around 98% across all age groups (oocyte: p = 0.499; sperm: p = 0.419). Oocyte provider age (<35, 35–37, 38–40, >40 years) showed no significant effect on pregnancy (69.2%, 76.1%, 67.4%, 69.4%; p = 0.634), clinical pregnancy (61.1%, 69.0%, 62.0%, 59.2%; p = 0.615), or live birth rates (53.4%, 59.2%, 49.6%, 57.1%; p = 0.581). Similarly, sperm provider age (≤40, >40 years) did not influence pregnancy (68.9%, 70.6%; p = 0.249), clinical pregnancy (60.6%, 63.7%; p = 0.726), or live birth rates (53.3%, 53.9%; p = 0.871). In contrast, woman’s age at transfer (<38, 38–42, 43–45, >45 years) significantly impacted the success of euploid embryo transfers. Pregnancy rates decreased with age statistically significant (71.7%, 73.6, 67.5%, 59.5%; p < 0.05). Clinical pregnancy (64.2%, 67.3%, 57.2%, 52.3%; p < 0.05) and live birth rates (57.1%, 58.7%, 50.0%, 40.5%; p < 0.05) also showed a clear age-related decline. Embryo quality was excluded as a factor, as the proportion of high-quality blastocysts (≥3BB) was equivalent across groups (<38: 95.4%, 38–42: 93.1%, 43–45: 96.4%, >45: 92.0%; p = 0.277). These findings emphasize the uterine environment as the primary determinant of live birth success in euploid embryo transfers. Limitations, reasons for caution While this study provides valuable insights, its retrospective design may limit the ability to control all potential confounders. Further prospective studies could help validate these findings and explore additional factors influencing euploid embryo reproductive outcomes. Wider implications of the findings These findings confirm that gamete provider’s age does not significantly affect live birth outcomes when transferring single euploid embryos. Improving uterine receptivity and optimizing obstetrical care in older women may enhance ART success rates. Trial registration number No