A Comparison of Sperm DNA Damage in the Neat Ejaculate of Sperm Donors and Males Presenting for their Initial Seminogram

Research Article

Austin J Reprod Med Infertil. 2015;2(3): 1014.

A Comparison of Sperm DNA Damage in the Neat Ejaculate of Sperm Donors and Males Presenting for their Initial Seminogram

Jaime Gosálvez¹*, José-LuisFernández², Jesus Yaniz³, Moises de la Casa4, Carmen López-Fernández1 and Stephen Johnston5

1Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, 20849 Madrid, Spain

2GeneticsUnit, Complejo Hospitalario Universitario A Coruña-INIBIC, A Coruña, Spain

3TECNOGAM, Instituto Universitario de Ciencias Ambientales (IUCA) and Departamento de Producción Animal y Ciencia de los Alimentos, University of Zaragoza, Spain

4GINEFIV, Calle José Silva, 18, 28043 Madrid, Spain

5School of Agriculture and Food Science, The University of Queensland, Australia

*Corresponding author: Jaime Gosálvez, Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, Spain

Received: April 14, 2015; Accepted: June 24, 2015; Published: June 29, 2015


A standardised value for characterization of sperm DNA fragmentation (SDF) and fertility prediction in patients is regarded as controversial and is one of the primary reasons why the assessment of the sperm DNA is not commonly incorporated into the routine seminogram. To address this conundrum we have conducted an analysis of the incidence of sperm DNA damage between sperm donors and a random cohort of males requested for a first seminogram. The underlying assumption was that sperm DNA damage is a neutral sperm characteristic and differences would not be expected between both cohorts. We analyzed SDF using the sperm chromatin dispersion assay in two large cohorts of individuals that included a comparison of seminograms from 210 sperm donors and 775 couples presenting to the clinic for first time. Results of the analysis revealed that sperm DNA damage cannot be considered as neutral parameter between the two populations (Donor: SDF Mean = 10.7; SD: 8.7; First seminogram: Mean =29.2; SD: 17.6; U-Mann-Whitney 20486; P 0.000). Receiving operating characteristics curves constructed under the parameters of this study showed that a SDF value of 16% was able to discriminate both cohorts of individuals with a sensitivity of 85% and a specificity of 75%. We suggest that when clinics are selecting for sperm donors, they are also likely to be indirectly selecting for a level of SDF which is in the order of 20 points lower than the level found in those couples presenting to the clinic for the first time.

Keywords: Andrology; Sperm DNA fragmentation; Male factor; Sperm donors


Even after 30 years of clinical practice, urologists have yet to reach general consensus about the precise role of sperm DNA fragmentation (SDF) in male infertility [1,2]. A lack of precision when using this parameter to predict fertility is no doubt contributing to this sense of controversy and preventing the universal inclusion of SDF as part of the standard seminogram; we propose a range of reasons for this variability. The first of these issues has to do with the plethora of possible pathologies associated with the original aetiology of sperm DNA damage. Sperm DNA damage has been linked to oxidative stress, protamination failure, meiotic failure and/or abortive apoptosis [1- 7]. Secondly, in addition to these organic causes, elevated levels of SDF have also been linked to lifestyle, pollution, bacterial infections and even high frequency energy exposure [8-10]. Thirdly, we must also be conscious of so-called “iatrogenic sperm DNA damage, which may be caused inadvertently as a result of improper ex vivo sperm handling or manipulation [11,12]. Finally, it is possible that the lack of predictability could also be associated with respect to the how and when the DNA damage is measured and what specific sperm delivery protocols are used to fertilise the oocyte or to prepare the sperm prior to syngamy. It is not surprising therefore, to find different threshold levels of sperm DNA fragmentation based on the specific fertilization procedures employed, for example, compare intrauterine insemination with ICSI [13].

Given the controversy that abounds about the actual role of SDF in fertility and for the purposes of this study, we have made the assumption, that SDF is a neutral sperm characteristic, i.e. it is an irrelevant sperm characteristic that may equally fluctuate irrespectively on the male that is analysed. For this null hypothesis to be upheld, we would expect to see no major difference in its prevalence when two different cohorts of individuals are compared. Consequently, we shall compare the level of SDF in the ejaculates of a sperm donor population with that of a large population of males presenting to the clinic for their first seminogram.

Material and Methods

This was a blind, retrospective, large cohort population study to assess the prevalence of SDF in sperm of donors (Group D; n=210) and males of couples presenting to a reproductive technology clinic for a Fist Seminogram: (Group FS; n=775). The study was conducted under the informed consent of all participants and according to the guidelines and protocols of the clinic’s ethical committee under the research project BFU-2013-44990R. The age range for Group D and FS was 23 ± 2.1 and 33 ± 12.3 years, respectively. Donors were selected using standard criteria where no personal or family chronic or serious illness that can affect offspring and no history of birth defects in family history, were considered. Negative serology for HIV, hepatitis B and C, syphilis, cytomegalovirus, and no trace of diseases such as Chlamydia and Gonococcus were also included. Normal karyotype and normo-zoospermia for seminogram before and after sperm cryopreservation were also considered as criteria for inclusion in the study.

SDF was directly assessed from the neat ejaculate immediately following sample liquefaction. This approach negated the adverse impact of iatrogenic damage as a confounding factor of the analysis [11]. SDF was assessed using Halosperm (Halotech DNA, Madrid, Spain). Details of the sperm chromatin dispersion test as used in the present investigation have been described elsewhere in previous studies [14]. Statistical analyses were performed with the Statistical Package for Social Sciences (SPSS v.11; Chicago, IL, USA). The test for normal data distribution was performed using Z-Kolmogorov- Smirnov and data comparison was conducted using a non-parametric Mann-Whitney U test, using anα of 0.05. Receiving operating characteristic (ROC curves) to assess for sensitivity and specificity were run under consideration of non-parametric analysis.


Descriptive statistics

The frequency distribution of the different subclasses of SDF following grouping of the data in terms of increasing and rank-size SDF values is shown in Figure 1. Sperm DNA fragmentation values did not conform to a normal distribution (Z-Kolmogorov-Smirnov for Group D = 2.52; P 0.000 / Z-Kolmogorov-Smirnov for Group P = 3.461; P 0.000; Figure 1); there was a common tendency for both groups to displace the curve towards a greater incidence of low values for SDF. Descriptive statistics for both groups are shown in Figure 2a; Group FS (Mean = 29.2; Median: 26.2; SD: 17.6) had a higher SDF value than group D (Mean = 10.7; Median: 9.0; SD: 8.7) (U-Mann- Whitney 20486; P 0.000).

Citation: Gosálvez J, Fernández J-L, Yaniz J, de la Casa M, López-Fernández C and Johnston S. A Comparison of Sperm DNA Damage in the Neat Ejaculate of Sperm Donors and Males Presenting for their Initial Seminogram. Austin J Reprod Med Infertil. 2015;2(3): 1014. ISSN:2471-0393