Samet Senel, Antonios Koudonas, Abdullah Said Sezgin, Abdullah Al-Mitwalli, Philippa Sangster, Mert Emre Erden, İlker Teke, Burcin Karamustafaoglu Balci, Murat Dursun
In men with NOA undergoing ICSI, the use of fresh testicular sperm is associated with improved fertilization and live birth rates compared with frozen-thawed sperm. Nevertheless, embryo development, implantation, and clinical pregnancy outcomes appear comparable between the two approaches. These findings support the preferential use of fresh sperm when feasible, while confirming that cryopreserved sperm remains an effective alternative when fresh sperm utilization is not possible.
INTRODUCTION: The optimal use of fresh versus frozen-thawed testicular sperm for intracytoplasmic sperm injection (ICSI) in men with non-obstructive azoospermia (NOA) remains controversial. Although cryopreservation facilitates asynchronous ICSI cycles, concerns persist regarding its potential adverse effects on sperm quality and reproductive outcomes. This systematic review and meta-analysis aimed to compare ICSI outcomes using fresh and frozen-thawed testicular sperm in men with NOA.
METHODS: A systematic search of PubMed Central, Web of Science, and Scopus was performed for studies published between January 1995 and May 2026. Comparative studies evaluating ICSI outcomes using fresh versus frozen-thawed surgically retrieved testicular sperm in NOA patients were included. Outcomes assessed were fertilization rate (FR), cleavage rate (CR), good embryo rate, implantation rate (IR), clinical pregnancy rate (CPR), and live birth rate (LBR). Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using fixed- or random-effects models according to heterogeneity.
RESULTS: Thirty-six studies comprising 5086 ICSI cycles were included. Fresh testicular sperm was associated with significantly higher FR (RR = 1.08, 95% CI 1.02-1.14; p = 0.0069) and LBR (RR = 1.13, 95% CI 1.03-1.23; p = 0.0067) compared with frozen-thawed sperm. No significant differences were observed in CR (RR = 1.01, 95% CI 0.98-1.03), good embryo rate (RR = 1.07, 95% CI 0.99-1.15), IR (RR = 1.00, 95% CI 0.81-1.23), or CPR (RR = 1.10, 95% CI 1.00-1.21; p = 0.054). No significant publication bias was detected.
CONCLUSION: In men with NOA undergoing ICSI, the use of fresh testicular sperm is associated with improved fertilization and live birth rates compared with frozen-thawed sperm. Nevertheless, embryo development, implantation, and clinical pregnancy outcomes appear comparable between the two approaches. These findings support the preferential use of fresh sperm when feasible, while confirming that cryopreserved sperm remains an effective alternative when fresh sperm utilization is not possible.