P-781 Managing a change of provider bank in a vitrified oocyte donation program

Abstract

Abstract Study question Does a change in provider bank affect the outcomes of a vitrified oocyte donation program and require laboratory and clinical adjustments? Summary answer In a vitrified oocyte donation program, a change in the provider bank does not affect patients’ outcomes nor require laboratory or clinical adjustments. What is known already Imported vitrified oocyte donation programs are a valuable strategy to provide oocyte donation treatments in settings were donor availability is low or absent. Little is known about how to a change in the provider oocyte bank should be managed in terms of laboratory or clinical adjustments in order not to jeopardize patients’ outcomes. Study design, size, duration Longitudinal cohort study conducted in a Tertiary IVF Center (Centro Scienze Natalità, IRCCS Ospedale San Raffaele, Milan, Italy) between September 2019 and October 2023. Participants/materials, setting, methods All couples undergoing their first imported vitrified oocyte donation cycle were included (n = 235). Oocytes (6 to 9 per cycle) were purchased from one bank (Bank A, Spain, EU) until December 2022 and then from a different bank (Bank B, Spain, EU) from January to October 2023. Single blastocyst-stage embryo transfer policy was adopted in all patients and the cumulative outcomes of patients treated with oocytes purchased from Bank A and Bank B were compared. Main results and the role of chance The number of provided oocytes was higher in Bank B compared to Bank A (8.0 ± 0.8 vs 6.5 ± 0.7, Mean ± SD, p < 0.01). Oocyte survival rates at thawing (87.2 ± 17.2 vs 91.2 ± 16.1 %, Mean ± SD), fertilization rates (75.7 ± 20.8 vs 78.4 ± 28.7, Mean ± SD) and blastulation rates (49.0 ± 28.0 vs 54.5 ± 27.5, Mean ± SD) were stable between Bank A and Bank B respectively, resulting in a higher number of blastocysts available for transfer in cycles performed with oocytes from Bank B compared to Bank A (3.5 ± 2.0 vs 2.4 ± 1.5, Mean ± SD, p < 0.01). Cumulative outcomes showed an improvement in cycles performed with Bank B compared to Bank A (implantation rates 73.8 % vs 62.6 %, ongoing pregnancy rates 69.8 % vs 56.3 %), despite not reaching a statistically significant difference. On multivariate logistic regression, the number of blastocysts available for transfer (OR 2.1, 1.7 -2.7 95% CI, p < 0.01) but not the Bank providing the vitrified oocytes (OR 0.99, 0.40 – 2.43) resulted as significant predictor of ongoing pregnancy. Limitations, reasons for caution Longer follow-up might strengthen our results, as several cycles performed with Bank B are still ongoing and cumulative live-birth rates cannot be currently calculated. In addition, the two banks used are located in the same country. Whether these results also apply to banks located in different settings needs further investigation. Wider implications of the findings Our results reassure about the possibility to manage a vitrified oocyte donation program using oocytes from different banks without jeopardizing patients’ outcomes and without the need for laboratory and clinical adjustments. Trial registration number not applicable