Tests detecting sperm DNA fragmentation (SDF) could be included in the clinical management of male infertility. TUNEL/PI is an innovative version of the TUNEL assay, and it is able to distinguish between two different populations: PI brighter and PI dimmer sperm. The aims of the study were to determine the average value of SDF in recruited men of proven fertility and to verify whether SDF discriminates between fertile and subfertile men independently from semen quality. In addition, we investigated the intra-individual coefficients of variation (CV) of SDF, by comparing two consecutive measures of SDF in the same patients. We found that in 67 recruited fertile men the average value of SDF was 35.8±14.8%. After matching fertile (n=58) to 99 sub fertile men (ratio 1:(13)) for age and semen quality, we observed that total SDF was significantly higher in the group of patients (44.5±917.2%) than in fertile subjects (36.3±14.8, P<0.005) and such a difference was totally due to SDF of PI brighter sperm (respectively: 27.4±13.0 vs 20.8±9.2, P<0.001) since SDF in PI dimmer population was similar in the two groups. Regarding the intra-individual CVs of SDF, they were quite low (8.9±5.8%, n=11) within 3 months and resulted lower than any conventional semen parameter. When the length between the two determinations of SDF was >3 months, the intra-individual CV for SDF increased to 17.1±15.0%, n=42. In conclusion, we demonstrated that SDF in PI brighter provides information on male infertility additional to those obtained by routine semen analysis. These results encourage us to continue the collection of fertile men to the aim of building the reference value for SDF as assessed by TUNEL/PI. In addition, we reported that within 3 months, SDF is the most stable intra-individual semen parameter.
27 Apr - 01 May 2013
European Society of Endocrinology