RESUMO
OBJECTIVE: Planned oocyte cryopreservation (OC) is being increasingly utilized worldwide. However, some women cannot accumulate sufficient oocytes because of poor response to stimulation. The POSEIDON classification is a novel system to classify patients with 'expected' or 'unexpected' inappropriate ovarian response to exogenous gonadotropins. Our study aimed to examine the prevalence of POSEIDON patients among women undergoing planned OC. STUDY DESIGN: We retrospectively reviewed the first cycles of 160 consecutive patients undergoing planned OC. Patients were classified into the four POSEIDON groups or as 'non-POSEIDON' based on age, AMH level and the number of oocytes retrieved. The primary outcome measure was the prevalence of POSEIDON patients. RESULTS: Overall, 63 patients (39.4 %) were classified as POSEIDON patients, 12 in group 1, 12 in group 2, 8 in group 3, and 31 in group 4. Compared to non-POSEIDON patients, POSEIDON patients had increased basal FSH levels and reduced serum AMH levels and antral follicle counts, required higher FSH starting doses and increased gonadotropin requirements and reached lower peak serum estradiol levels. Additionally, POSEIDON patients had a lower number of oocytes retrieved (7.6 ± 3.1 vs.20.2 ± 9.9, p < 0.001) and vitrified (5.8 ± 2.9 vs.14.7 ± 6.8, p < 0.001) than non-POSEIDON counterparts, respectively. CONCLUSION: We found a high prevalence of patients being classified as low prognosis according to the POSEIDON criteria among patients seeking planned OC. POSEIDON patients had increased gonadotropin requirements and a significantly lower number of oocytes retrieved and vitrified. This novel, unexpected finding adds clinically relevant information for counselling and management of patients undergoing planned OC.