RESUMO
Sperm premature chromatin condensation (PCC) has been considered as the second cause of failed fertilization post-intracytoplasmic sperm injection (post-ICSI). Cytoplasmic factors, including oocyte cytoplasmic immaturity have been suggested to induce PCC sperm. However, recent studies suggest that sperm chromatin anomaly might also lead to PCC sperm. During this study, human sperm from infertile patients with protamine deficiency or with adequate amount of protamine assessed by chromomycin A3 were injected into metaphase II mouse oocyte, treated with colcemid. Chromatin analysis was carried out on the injected oocyte. The results of this study show that contrary to the percentage of intact sperm, percentage of PCC sperm was significantly higher in oocytes injected with protamine deficient sperm (36.43 +/- 4.46) compared to oocytes injected with sperm with an adequate amount of protamine (11.99 +/- 3.54, P < 0.001). A significant correlation was also observed between percentage of PCC sperm and protamine deficiency (r = 0.46, P = 0.004). Therefore, it can be suggested that oocytes injected with protamine deficient sperm have a higher chance of forming PCC sperm and may result in failed fertilization post-ICSI.