Age does not adversely affect sperm retrieval in men undergoing microdissection testicular sperm extraction

Objective To evaluate the effect of male age on the outcome of microdissection testicular sperm extraction (micro-TESE) and assisted reproductive technology. Design Clinical retrospective study. Setting Center for reproductive medicine at a tertiary university hospital. Patient(s) One thousand sixty-seven men with nonobstructive azoospermia. Intervention(s) Micro-TESE, with intracytoplasmic sperm injection when sperm found. Main Outcome Measure(s) Sperm retrieval and clinical pregnancy. Result(s) Sperm were successfully retrieved by micro-TESE in 605 men (56.6%) overall. Sperm retrieval rates (SRRs) were higher in men ≥50 years old than men <50, (73% in men ≥50, 56% in men <50). Of the 44 men ≥50 years old, men who had successful micro-TESE had larger mean testis volume (20.8 cc vs. 12.5 cc), a higher frequency of hypospermatogenesis (5.6% vs. 0%), and a lower frequency of Sertoli cells only (12.5% vs. 80%) on diagnostic biopsy. Clinical pregnancy rates were lower in partners of men ≥50 than in partners of men <50 (48% in men <50, 25% in men ≥50). Lower pregnancy rates may be at least partially explained by older female partners for men ≥50 compared to men <50 (mean age 38.0 vs. 36.2 years). Sperm were successfully retrieved across all age groups, and there was no upper male age limit above which sperm could not be retrieved. Conclusion(s) Overall, SRRs in men undergoing micro-TESE are not negatively affected by age. Despite successful sperm retrieval in older men with micro-TESE, couples have the best chance of clinical pregnancy with a female partner <35 years old. Some older men with azoospermia may have secondary azoospermia with hypospermatogenesis, explaining the high sperm retrieval rate.