Purpose: To characterize the likelihood of cryopreserving enough oocytes for 50%, 60%, or 70% estimated live birth rate (eLBR) with 1-2 planned oocyte cryopreservation (Pl-OC) cycles.
Methods: We performed a retrospective cohort study utilizing all patients completing ≥ 1 Pl-OC cycle from 2016 to 2018 at a large single-center OC program. Subjects were categorized by age at retrieval and number of cycles. We extrapolated age-based oocyte thresholds for 50%, 60%, or 70% eLBR from previously published data. We calculated the proportion of subjects overall, and for each age group, whose number of frozen oocytes was greater than or equal to their age-based threshold for a 50%, 60%, or 70% eLBR after 1 and 2 cycles. OR for 60% eLBR with one cycle was calculated for age and AMH cutoff values and corroborated with logistic regression.
Results: A total of 1241 subjects, completing 1799 Pl-OC cycles, were included. With one cycle, 66% (819/1241) achieved ≥ 50% eLBR and 51% (634/1241) achieved 70% eLBR. With two cycles, 79.6% (988/1241) attained ≥ 50% eLBR and 65.5% (813/1241) achieved 70% eLBR. Achieving 50%, 60%, or 70% eLBR with 1-2 cycles was significantly associated with both age (p < 0.001) and AMH (p < 0.001). Age < 37.5 and AMH > 1.995 were independently associated with attaining 60% eLBR with one cycle (age: OR 13.73; 95%CI 9.16-20.57, p < 0.001; AMH: OR 7.32; 95% CI 5.50-9.76, p < 0.001).
Conclusions: Younger age and higher AMH were associated with achieving 50%, 60%, or 70% eLBR thresholds with Pl-OC. Nevertheless, almost all subjects were successfully able to preserve enough oocytes for ≥ 50% eLBR in 1-2 cycles.
Keywords: Fertility preservation; Live birth rate; Oocyte cryopreservation.