Comparison between chromatin condensation and morphology from testis biopsy extracted and ejaculated spermatozoa and their relationship to ICSI outcome.

A significant association between male subfertility, imperfect spermiation and abnormal nuclear condensation has been suggested. The DNA content of spermatozoa might be responsible for inducing alterations in sperm morphology. The final nuclear shape, which is species-specific, depends on chromatin condensation during spermatogenesis as well as a precise organization of DNA within the nucleus. Many reports have described the association between disturbances in sperm chromatin condensation, morphology and male infertility. Chromatin condensation is achieved by gradual substitution of lysinerich somatic histones by testis-specific histone and finally by protamine. In this study two groups of patients were compared: the first consisted of 63 patients who had undergone intracytoplasmic sperm injection (ICSI) with freshly ejaculated spermatozoa whereas the second included 47 patients assigned to ICSI with testes biopsy-extracted spermatozoa. In both groups chromatin condensation was assessed by aniline blue staining and morphology evaluated according to strict criteria. The condensed chromatin and morphology of spermatozoa were significantly (P < 0.0001) less in the second group compared to the first. However the fertilization, cleavage, implantation and pregnancy rates were almost the same in both investigated groups. There was no significant difference between the two groups with respect to ICSI outcome. The percentage of chromatin condensation (nuclear maturity) and morphologically-normal spermatozoa were significantly higher (P < 0.0001) in the ejaculated spermatozoa than in those from testis biopsy but the ICSI outcome (fertilization, cleavage, implantation and pregnancy rates) was the same. In view of these results the fertilization capability and the embryo quality obtained using testis biopsy extracted spermatozoa is not influenced by chromatin condensation and sperm morphology in testicular sperm extraction (TESE)-ICSI programmes. Therefore, it could be said that neither chromatin condensation nor morphology of testis extracted sperm could predict the fertilization, implantation and pregnancy rate in TESE-ICSI programmes.