Autologous sperm usage after cryopreservation-the crucial impact of patients' characteristics.

Background: The wide implementation of sperm freezing presents a growing burden on sperm banks.

Objectives: To evaluate sperm freezing and usage patterns over 30 years, according to demographic parameters of age at first cryopreservation and number of children, and indication for cryopreservation.

Material And Methods: This retrospective, population based, cohort study included all sperm cryopreservation cases performed at a tertiary referral center from October 1993 to December 2021, among patients aged 18 years and older. First, we determined the interval between first sperm sample and use. Then, we examined sperm usage separately for: (1) age, comparing patients grouped into 5-year age cohorts; (2) paternal status according to number of children; (3) indication, comparison among seven indications. Secondary analysis included correlations between main age groups and paternal status versus the four most common indications found.

Results: During the study period 1490 men who cryopreserved sperm met the inclusion criteria. Average age at cryopreservation of the first sample was 33.9 ± 8.1 years. Average age at first sperm use was 37 ± 8.5 years. Cumulative sperm usage was 38.7% after 17.8 years. Increasing age was associated with progressive increase in sperm usage rate and shorter preservation period. Use significantly decreased with increasing number of children. Examination of seven reasons for sperm cryopreservation found the highest cumulative sperm usage was related to azoospermia (67.7%), followed by functional cryopreservation (39.3%), oligoasthenoteratospermia (27.3%), other (26.5%), patient's request (24%), cancer (19%), and systemic disease (7.2%). Secondary analysis defined specific usage patterns mainly related to age and indication, with less of an effect based on the number of children.

Discussion And Conclusion: After decades of cryopreservation, the paradigm of sperm cryopreservation is mostly related to cancer patients. This should be reevaluated and evolve to include broader patient-targeted factors and perceptions.