To compare the outcome of intracytoplasmic sperm injection (ICSI) cycles  using epididymal and testicular sperm in patients with obstructive azoospermia (OA);  using surgically retrieved sperm in patients with OA and non-obstructive azoospermia (NOA); and  using fresh and frozen-thawed sperm.
Meta-analysis of published data.
Assisted conception unit.
Ten reports (734 cycles: 677 transfers) were identified as suitable to assess source of sperm; 9 reports (1,103 cycles: 998 transfers) to assess etiology; and 17 reports (1,476 cycles: 1,377 transfers) to assess the effect of cryopreservation.
Surgical sperm retrieval/ICSI.
Main outcome measure(s)
Fertilization rate (FR), implantation rate (IR), clinical pregnancy rate (CPR), and ongoing pregnancy rate (OPR) per embryo transfer.
Meta-analysis demonstrated no significant difference in any outcome measure between the use of epididymal or testicular sperm in men with OA. Meta-analysis showed a significantly improved FR (relative risk [RR] 1.18; 95% confidence interval [CI]: 1.13–1.23) and CPR (RR 1.36; 95% CI: 1.10–1.69) in men with OA as compared to NOA with a nonsignificant increase in OPR. There was no difference in either IR or miscarriage rate between the two groups. Comparing fresh with frozen-thawed epididymal sperm there was no difference in FR or IR, a significantly higher CPR (RR 1.20; 95% CI: 1.0–1.42), and no difference in OPR. No difference in fertilization or pregnancy outcome was noted when the testicular cycles were analyzed separately, but IR was significantly impaired using frozen-thawed sperm (RR 1.75; 95% CI: 1.10–2.80).
Meta-analysis of published data confirms that etiology of azoospermia and cryopreservation of surgically retrieved sperm impacts on ICSI outcome, and allows us to make several recommendations for clinical practice. Origin of sperm, in men with similar etiology, does not affect outcome.