P-552 Unveiling associated factors to in vitro embryonic ploidy: Insights from 8194 blastocysts by Next Generation Sequencing

Abstract Study question What factors are associated with an increased probability of having aneuploid or mosaic embryos in vitro? Summary answer Maternal age and biopsy day significantly influence aneuploidy, while trophectoderm quality impacts both aneuploidy and embryo mosaicism. What is known already Embryonic aneuploidy and mosaicism are critical factors affecting the success of in vitro fertilization. Several studies have demonstrated that advanced maternal age is the most important variable associated with chromosomal abnormalities. However, the influence of other factors, including the day of the blastocyst biopsy and the quality of specific embryonic components, such as the trophectoderm, on the likelihood of aneuploidy and mosaicism is less understood. Study design, size, duration This retrospective study involved the analysis of 8,194 blastocyst embryos derived from 2,180 IVF/ICSI cycles at a specialized assisted reproduction clinic. The study spanned 7 years, from 2017 to 2023, focusing on identifying factors influencing embryonic ploidy Participants/materials, setting, methods Retrospective analysis of 8194 blastocysts from 2180 IVF/ICSI cycles at a single fertility center. Evaluated maternal age, paternal age, day of embryo biopsy, inner cell mass and trophectoderm quality, embryo biopsy operator, fertilization technique, using logistic regression to assess impact on ploidy (euploid, aneuploid, mosaic). Analysis identified significant factors influencing ploidy, adjusting for confounders. Statistical significance at p < 0.05. Main results and the role of chance The analysis of 8,194 blastocyst embryos highlighted significant findings. Maternal age showed a considerable impact on aneuploidy with a p-value <0.001 and an odds ratio (OR) of 1.74, indicating a strong association. Similarly, the day of embryo biopsy was a significant factor (p < 0.001, OR = 1.51) emphasizing its influence on embryo aneuploidy. The quality of the trophectoderm was a crucial factor, with a notable correlation with both aneuploidy (p < 0.001, OR = 1.78) and mosaicism (p < 0.001, OR = 1.28). Further analysis was also performed to find the variables associated with mosaicism, and the only significant variable was quality of trophectoderm increasing the probability of mosaicism by 28%. These statistical values underscore the robustness of the study’s conclusions. The large sample size and the application of logistic regression models further minimized the role of chance, enhancing the reliability of these findings. The research provides significant insights into the factors influencing embryonic ploidy, extending beyond the well-recognized impact of maternal age. It underscores the importance of considering these variables in clinical assessments during fertility treatments, particularly in evaluating the risk of chromosomal abnormalities. Limitations, reasons for caution The study’s retrospective nature limits causal inferences. The findings need validation in prospective, multicenter studies to establish broader applicability and account for potential biases. Wider implications of the findings These results contribute to the understanding of the factors associated with aneuploidy and embryonic mosaicism, beyond maternal age. Integrating the day of embryo biopsy and trophectoderm quality as key factors into clinical evaluation that could improve clinical decision-making in fertility treatments, especially in assessing the risk of chromosomal abnormalities. Trial registration number Non-Clinical trials