Sperm chromatin quality and DNA integrity in partial versus total globozoospermia.

Globozoospermia is a severe form of teratozoospermia with low incidence in infertile patients, considered as one of the important causes of male infertility. The objective was to investigate the chromatin/DNA integrity as well as apoptosis in ejaculated spermatozoa of cases with partial or total globozoospermia. Fifty-seven semen samples were divided into three groups of partial globozoospermia (n = 17), total globozoospermia (n = 10) and normozoospermia (control; n = 30). Sperm chromatin condensation, DNA integrity and apoptosis were assessed using cytochemical assays. The results showed significant differences in sperm parameters of count and motility between two case groups versus controls. The percentages of spermatozoa with abnormal chromatin packaging and protamine deficiency were significantly higher in total and partial globozoospermic men compared to normozoospermic samples. Also, the rates of TUNEL-positive spermatozoa were significantly increased in both globozoospermic cases with respect to the control (18.3 ± 10.1 and 12.3 ± 9.2 versus 5.9 ± 3 respectively). However, no significant differences were noticed between two subgroups of patients with regard to sperm DNA denaturation, DNA fragmentation and apoptosis. Abnormal chromatin packaging, DNA damage and apoptosis were significantly higher in cases than controls. The sperm chromatin/DNA anomalies may be considered as one of the main aetiology of ART failure in globozoospermic patients.

Prolonged incubation of processed human spermatozoa will increase DNA fragmentation.

One of the causes of failure in ART is sperm DNA fragmentation which may be associated with long period of spermatozoa incubation at 37 °C. The objective was to evaluate the rate of sperm DNA fragmentation using the sperm chromatin dispersion (SCD) test after swim-up at different time intervals prior to use. In this prospective study, 21 normozoospermic specimens were analysed. The samples were incubated at 37 °C after preparation by direct swim-up. DNA fragmentation was assessed at different time intervals (0, 1, 2 and 3 h) using SCD test. Spermatozoa with no DNA fragmentation showed large- or medium-sized halos, and sperm cells with DNA fragmentation showed either a small halo or no halo. The rates of normal morphology and progressive motility after sperm processing were 72.33 ± 2.53% and 90 ± 1.02%, respectively. The rate of sperm DNA fragmentation was significantly higher after 2 h (8.81 ± 0.93%, P = 0.004) and 3 h (10.76 ± 0.89%, P < 0.0001) of incubation compared to 0 h (4.38 ± 0.8%). A positive correlation was found between the incubation time and sperm DNA damage (P < 0.0001). Prolonged incubation of prepared normozoospermic samples at 37 °C is associated with higher rates of sperm DNA fragmentation. Therefore, sperm samples intended for ART procedures should be used within 2 h of incubation at 37 °C.