title: Prolonged incubation of processed human spermatozoa will increase DNA fragmentation.
abstract: 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.
authors.affiliation: Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran; Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Nabi
authors.forename: M A
authors.initials: MA
authors.lastname: Khalili
authors.forename: I
authors.initials: I
authors.lastname: Halvaei
authors.forename: F
authors.initials: F
authors.lastname: Roodbari
mesh_terms: D002843:Chromatin / Q000302:isolation & purification; D053938:DNA Fragmentation; D005821:Genetic Techniques; D006801:Humans; D008297:Male; D055101:Semen Analysis / Q000379:methods; D012662:Semen Preservation / Q000009:adverse effects* / Q000379:methods; D013094:Spermatozoa; D013696:Temperature
chemical_list: D002843:Chromatin
keywords: Incubation at 37 °C; SCD test; normozoospermia; sperm DNA fragmentation