To determine the frequency of sperm cells with fragmented DNA in semen samples from men with genitourinary infection by Chlamydia trachomatis and Mycoplasma and the influence of antibiotic therapy, using the sperm chromatin dispersion test with the Halosperm kit.
Design
Prospective study.
Setting
University-affiliated reproductive medicine center, medical genetics laboratory, and academic biology center.
Patients
One hundred forty-three male member of couples attending the andrology infertility center and a group of 50 fertile subjects. The effect of antibiotic treatment was evaluated in 95 male patients.
Interventions
None.
Main Outcome Measures
Classical semen analysis (concentration, motility, morphology, and vitality), sperm DNA fragmentation, and clinical outcome.
Results
The mean percentage of sperm cells with fragmented DNA was 35.2% +/- 13.5%, 3.2 times higher than in the control fertile group (10.8% +/- 5.6%). Concentration, morphology, and motility were also significantly affected but to a much lower degree. Sperm vitality was not significantly affected. After 3.8 +/- 2.2 months of antibiotic treatment, the mean frequency of spermatozoa with fragmented DNA decreased from 37.7% +/- 13.6% to 24.2% +/- 11.2%. Sperm concentration and motility were not significantly improved. In a group of 16 couples who attempted pregnancy during antibiotic treatment course, only 12.5% achieved pregnancy. However, in a group of 14 couples who attempted pregnancy after finishing the antibiotic treatment, 85.7% achieved it. The only significant differences found between groups was the rate of sperm DNA fragmentation and morphology.
Conclusions
Patients with genitourinary infection by Chlamydia trachomatis and Mycoplasma have increased sperm DNA fragmentation in comparison with fertile controls. This increase is proportionally greater than the influence on classical semen parameters and could result in a decreased fertility potential. Antibiotic therapy appears to be important in providing a remedy for infection-induced high DNA fragmentation levels.
Esteves SC et al., 2020·Andrologia·Free full text on PubMed Central
We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations. Of these, 13 recommendations concern technical aspects of sperm DNA fragmentation testing, including pre-analytical information, clinical thresholds and interpretation of results. The remaining 28 recommendations relate to indications for sperm DNA fragmentation testing and clinical management. Clinical scenarios like varicocele, unexplained infertility, idiopathic infertility, recurrent pregnancy loss, intrauterine insemination, in vitro fertilisation/intracytoplasmic sperm injection, fertility counselling for men with infertility risk factors and sperm cryopreservation have been contemplated. The bulk evidence supporting the recommendations has increased in recent years, but it is still of moderate to low quality. This guideline provides clinicians with advice on best practices in sperm DNA fragmentation testing. Also, recommendations are provided on possible management strategies to overcome infertility related to sperm DNA fragmentation, based on the best available evidence. Lastly, we identified gaps in knowledge and opportunities for research and elaborated a list of recommendations to stimulate further investigation.
Related research
Anti-Infective and Anti-Inflammatory Agents · Antibiotics in Reproductive Care
Mollicutes are frequently isolated from sperma of infertile men. The potential effect on the fertility of mollicute infection is controversial as is antibiotic therapy. In our andrological patients, the prevalence of mollicutes is approximately 10%. To evaluate the benefit of antibiotic therapy, we investigated two groups of group 1-patients with positive or negative mollicute cultures and normal spermiogram; morphological changes on spermatozoa were particularly evaluated (n = 40); group 2 - patients with positive mollicute cultures treated with doxycycline or erythromycin. Sperm parameters were analysed before and after treatment (n = 20). When infected and non-infected sperma from group 1 were compared, the only difference found was an alteration of the sperm tail (p less than 0.005). Light microscopy and electron microscopy (EM) often revealed coiled tails which were probably due to adhesion of mollicutes (EM). The most frequently observed pathology in group 2 was found in patients with teratoasthenozoospermia. Compared with the post-therapy spermiogram, a significant difference was only observed in spermatozoal morphology (p less than 0.005). Therefore, we conclude that mollicutes produce important alterations in the human spermatozoal morphology, especially in the tail which appears in a spiral form. Since teratozoospermia is considered to be an important factor of infertility in man, antibiotic therapy is recommended in cases of mollicute involvement.
To investigate the rate of sperm DNA fragmentation in male partners of women with recurrent pregnancy loss and fertile control women.
Systematic review and meta-analysis.
Not applicable. PATIENT(S): A total of 579 male partners of women with recurrent pregnancy loss and 434 male partners fertile control women. INTERVENTION(S): Prospective studies were identified through a Pubmed search. Recurrent pregnancy loss was defined as two or more previous pregnancy losses. Fertile control women had a history of a live birth or ongoing pregnancy. MAIN OUTCOME MEASURE(S): The primary outcome was the rate of sperm DNA fragmentation. The summary measures were reported as mean difference with 95% confidence interval (CI). RESULT(S): Fifteen prospective studies were included in a qualitative review. Pooled data from 13 studies with sufficient data for meta-analysis suggest that male partners of women with a history of recurrent pregnancy loss have a significantly higher rate of sperm DNA fragmentation compared to the partners of fertile control women: mean difference 11.91, 95% CI 4.97-18.86. CONCLUSION(S): These findings support an association between sperm DNA fragmentation and recurrent pregnancy loss. However, given the significant heterogeneity between studies and lack of prospective pregnancy outcome data, further large prospective studies are needed.
Chlamydia trachomatis infection is one of the most common sexually transmitted diseases. Its effect on male fertility, however, is still controversial. In this study, 284 male partners of infertile couples consulting the Center of Studies in Reproductive Biology (CEBRE) were analyzed. The incidence of C. trachomatis infection among male partners of infertile couples was 38.6%. There were no significant differences between infected and noninfected infertile men in any of the sperm parameters assessed (sperm concentration, motility and morphology). The results of the three bioassays developed to evaluate sperm physiology, namely spermatozoa-zona pellucida binding, acrosome reaction stimulated with human follicular fluid and zona-free hamster oocyte penetration, showed no differences between infected and noninfected men. Electron microscopy studies suggest that spermatozoa are active agents in the dissemination of the chlamydial infection; they could be acting as 'vehicles' for the pathogens. These, and other results, suggest that the possible effect of C. trachomatis on male fertility is not due to alterations in sperm 'quality' or function, but rather to the transmission of the disease to female partners, causing inflammatory processes and promoting the generation of antisperm antibodies.
Mowla S et al., 2025·eLife·Free full text on PubMed Central
Several studies have associated seminal microbiota abnormalities with male infertility but have yielded differing results owing to their limited sizes or depths of analyses. The semen microbiota during recurrent pregnancy loss (RPL) has not been investigated. Comprehensively assessing the seminal microbiota in men with reproductive disorders could elucidate its potential role in clinical management. We used semen analysis, terminal-deoxynucleotidyl-transferase-mediated-deoxyuridine-triphosphate-nick-end-labelling, Comet DNA fragmentation, luminol reactive oxidative species (ROS) chemiluminescence, and metataxonomic profiling of semen microbiota by 16S rRNA amplicon sequencing in this prospective, cross-sectional study to investigate composition and bacterial load of seminal bacterial genera and species, semen parameters, ROS, and sperm DNA fragmentation in men with reproductive disorders and proven fathers. 223 men were enrolled, including healthy men with proven paternity (n=63), the male partners in a couple encountering RPL (n=46), men with male factor infertility (n=58), and the male partners of couples with unexplained infertility (n=56). Rates of high sperm DNA fragmentation, elevated ROS, and oligospermia were more prevalent in the study group compared with control. In all groups, semen microbiota clustered into three major genera-dominant groups (1, Streptococcus; 2, Prevotella; 3, Lactobacillus and Gardnerella); no species clusters were identified. Group 2 had the highest microbial richness (p<0.001), alpha-diversity (p<0.001), and bacterial load (p<0.0001). Overall bacterial composition or load has not been found to associate with semen analysis, ROS, or DNA fragmentation. Whilst global perturbation of the seminal microbiota is not associated with male reproductive disorders, men with unidentified seminal Flavobacterium are more likely to have abnormal seminal analysis. Future studies may elucidate if Flavobacterium reduction has therapeutic potential.
Guadalupe Gallegos, Benito Ramos, Rebeca Santiso, Vicente Goyanes, Jaime Gosálvez, José Luis Fernández
G Gallegos, B Ramos, R Santiso, V Goyanes, J Gosálvez, J Fernández
PMID 17953955 17953955 DOI 10.1016/j.fertnstert.2007.06.035 10.1016/j.fertnstert.2007.06.035 Gallegos et al. 2008, Gallegos 2008
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