P-404 Trends in Oocyte Vitrification: Patient Demographics and Outcomes from 2015 to 2023

Study question How have the demographics and clinical outcomes of patients undergoing oocyte vitrification evolved over the period 2015-2023? Summary answer Oocyte vitrification has increased, with more foreign patients, decreasing mean age, and more vitrified oocytes. Warming rates remain low, and survival correlates with ovarian reserve. What is known already Oocyte vitrification is a widely used fertility preservation strategy. Age and ovarian reserve markers impact success, but long-term trends remain underexplored. Understanding demographic and clinical shifts, including nationality trends, survival rates, and warming rates, is essential for refining fertility preservation strategies and patient counseling. Study design, size, duration A retrospective cohort study including 936 patients who underwent oocyte vitrification between 2015-2023 at a single fertility center. Trends in patient demographics, ovarian reserve, survival rates, and vitrification outcomes were analyzed using linear regression models. Participants/materials, setting, methods Patients undergoing vitrification were included. Data analyzed: nationality, age, AMH, AFC, vitrified/warmed oocytes, and survival rates. Statistical tests identified trends and associations in survival and warming rates. Main results and the role of chance Patient numbers increased from 35 (2015) to 306 (2023). Mean age declined (-0.30 years/year, p = 0.007), with an overall mean of 36.4 years (2015-2023). AMH remained stable (2.33 ng/mL in 2015 vs. 2.01 ng/mL in 2023, p = 0.840). Vitrified oocytes rose (248 in 2015 vs. 910 in 2023, p = 0.002). Oocyte survival rates were negatively correlated with age (-0.81, p < 0.01) and positively with AMH (0.89) and AFC (0.99). In the available data, the mean oocyte survival rate for the 37-40 age group was 63.9%, while insufficient data were available for other age groups. As to warming rates 45.7% of 2015 patients underwent warming, compared to 5.6% from 2023. Limitations, reasons for caution Single-center data limits generalizability. External factors such as policy changes and economic shifts may influence trends. Limited survival rate data for specific age groups restricts definitive conclusions on age-related trends. Wider implications of the findings Decreasing patient age highlights evolving fertility awareness. The increasing international patient demand underscores the importance of accessible reproductive care policies. The association between ovarian reserve markers and survival rates can enhance fertility preservation counseling. Trial registration number No