Evaluation of meiotic impairment of azoospermic men by fluorescence in situ hybridization

Objective: To identify predictive criteria for the existence of spermatogen esis in nonobstructive azoospermic men. Design: Prospective study. Setting: Andrology laboratory at a teaching hospital. Patient(s): Twenty-two azoospermic men were divided into three groups by qu alitative testicular histopathology and the presence of spermatozoa in minc ed biopsies. Intervention(s): Testicular biopsies evaluation. Main Outcome Measure(s): The presence of spermatozoa and/or mature spermati ds, the percentage of sex vesicle formation (X and Y chromosomes in proximi ty), and the pairing of the two 18 homologous chromosomes. Result(s): Spermatozoa and mature spermatids were found in 17 study patient s. Whenever few mature spermatids and/or spermatozoa were found, the rates of X-Y and 18 bivalents were significantly higher (mean +/- SD, 73% +/- 13. 3% and 91% +/- 7.1%) than those in cases of spermatocyte maturation arrest (23% +/- 8.0% and 60% +/- 11.8%, respectively). Conclusion(s): Pairing of chromosomes during meiosis is apparently related to the progression of spermatogenesis. Consequently, high rates of bivalent formation increase the prospect of focal spermatogenesis in the testis, de spite the failure to identify mature spermatids in the specific testicular biopsy under examination. (C) 2000 by American Society for Reproductive Med icine.