COUNTING EGGS BEFORE THEY HATCH: UTILIZATION OF OOCYTES AFTER PLANNED OOCYTE CRYOPRESERVATION

Women are increasingly electing to cryopreserve oocytes in order to delay childbearing. Planned oocyte cryopreservation often requires significant investment, yet there is a paucity of data to guide patients on their likelihood of obtaining significant returns. In addition, the prediction of live birth rates after using cryopreserved oocytes remains an area of active investigation. We aimed to characterize patterns in planned oocyte cryopreservation over the last decade, determine the percentage of patients who returned to utilize cryopreserved oocytes, and develop a counseling tool for patients on the anticipated number of cryopreserved oocytes based on age and AMH. We performed a retrospective review of women undergoing planned oocyte cryopreservation at a single, large, university-affiliated REI practice from January 2010 to December 2020. Oocyte cryopreservation for cancer diagnosis, TESE failure, or inability to produce a semen sample on the day of oocyte retrieval were excluded. The primary outcome was the percentage of patients who returned to utilize cryopreserved oocytes for fertilization and subsequent embryo transfer or PGT-A. Secondary outcomes were the number of planned oocyte cryopreservation cycles per year, the number of oocyte thaw/warm cycles per year, and the mean number of cryopreserved oocytes based on age (<25, 25-30, 30-35, 35-42, >42) and AMH (<0.5 ng/mL, 0.5-1 ng/mL, 1-3.5 ng/mL, >3.5 ng/mL). 2,845 planned oocyte cryopreservation cycles were performed between January 2010 and December 2020. The mean patient age at cycle start was 36.6 ± 3.6 years. The number of oocyte cryopreservation cycles increased from 2010 (n=9) to 2019 (n=499). The number of oocyte thaw/warm cycles similarly increased between 2010 (n=1) and 2019 (n=100), and the majority of thaw/warm cycles (77.3%) took place within the last three years (2018-2020). Notably, 2020 witnessed a decrease in both planned oocyte cryopreservation (n=215) and oocyte thaw/warm (n=84) cycles due to the COVID-19 pandemic. AMH was the strongest predictor of the mean number of cryopreserved oocytes, and the highest yield (mean 18.6) occurred in patients 30-35 years old with an AMH >3.5 ng/mL. During the study period, 12.4% (267/2,159) of patients returned to utilize cryopreserved oocytes. The number of planned oocyte cryopreservation cycles increased each year between 2010 and 2019; however, a minority of women (12.4%) ultimately returned to utilize cryopreserved oocytes.