Conventional semen parameters and DNA fragmentation in relation to fertility status in a Greek population

Abstract

Objectives: Our study aimed to investigate the possible correlations between conventional seminal parameters and DNA fragmentation in specific groups of Greek men, selected in relation to their fertility history and to verify the validity of the recent WHO reference values for the basic semen analysis in this population.

Study design: A total of 770 subject data were evaluated in three distinct groups: fertile men with children naturally conceived within one year of unprotected intercourse (n=78), subfertile men, having achieved pregnancies either naturally or by Assisted Reproduction Techniques, not resulting in live births (n=153) and infertile men, failing to produce either pregnancies or children (n=539). Semen volume, sperm concentration, total count, rapid and total progressive motility and morphology were evaluated following the World Health Organization (2010) methods. DNA fragmentation was assessed by the Sperm Chromatin Dispersion assay. The 5th percentile, as well as the 95% confidence intervals (CI) for each parameter, were calculated by the method of bootstrapping. Statistical correlations between the examined parameters were sought using the Spearman R test (p<0.05).

Results: A significant inverse correlation was established between DNA fragmentation and sperm concentration, total count, progressive motility (rapid and total) and normal morphology in subfertile and infertile men (p<0.05). No statistically significant correlations were remarked between the conventional semen parameters and the levels of DNA fragmentation in our group of fertile men. Concordance was established between the reference limits issued by the WHO 2010 for the basic semen parameters and semen quality of fertile men in the studied population.

Conclusions: The variability of correlations established between DNA fragmentation and the conventional seminal profile in relation to fertility status indicates that they are independent attributes of semen quality, justifying the assessment of both during a comprehensive evaluation of male infertility. Moreover, the WHO 2010 reference limits were found adequately descriptive of seminal normality in Greek men.

Keywords: DNA damage; Infertility; Semen parameters.