Spermatozoa as harbingers of mortality: the curious link between semen quality and life expectancy

Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology

Björndahl L et al., 2022 · Human Reproduction

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.

Semen quality and lifespan: a study of 78,284 men followed for up to 50 years

Priskorn L et al., 2025 · Human Reproduction

Lab-based semen parameters as predictors of long-term health in men-a systematic review

Nedelcu S et al., 2024 · Hum Reprod Open · Free full text on PubMed Central

Can semen parameters predict long-term health outcomes in men? There is a lack of evidence to suggest a higher risk of comorbidities in men with poor semen concentration. Male infertility has been long associated with a higher mortality risk and possibly higher chance of developing comorbidities but there has been less focus on semen analysis as a potential predictive factor. We searched PubMed/MEDLINE, EMBASE, and EBM databases from inception to December 2023. MESH term strategy: heading 1 ('OR', semen analysis, sperm count, sperm parameter*, male infertility, azoospermia, aspermia, oligospermia, teratozoospermia, asthenozoospermia) 'AND' heading 2 ('OR', morbidity, mortality, diabetes, cancer, cardiovascular, death, hypertension, stroke, long-term health). We included all studies that analyzed the risk of mortality and/or future development of comorbidities in men with at least one semen analysis. Case series and reviews were excluded. A narrative synthesis was done for all studies and meta-analysis where possible. Odds ratio (ORs) (95% CI, P-value) were calculated for all men with one suboptimal semen parameter and associated with the risk of a particular outcome. The risk of bias was assessed with QUADAS-2. MAIN Twenty-one studies were finally included. There was either a high or unclear risk of bias in all studies. The results only allowed for meta-analysis on categories of sperm concentration. We found a 2-fold increase in mortality risk in azoospermic men compared to oligospermic (OR 1.96, 95% CI: 1.29-2.96) and normozoospermic (OR 2.00, 95% CI: 1.23-3.25) groups, but not in oligospermic compared to normozoospermic (OR 1.04, 95% CI: 0.52-2.09). There was no difference in risk of cardiovascular disease in any of the sperm concentration groups (azoospermic-oligospermic OR 0.94, 95% CI: 0.74-1.20, azoospermic-normozoospermic OR 1.11, 95% CI: 0.71-1.75, and oligospermic-normozoospermic OR 1.12, 95% CI: 0.80-1.55). OR for diabetes in azoospermic men was higher only compared to oligospermic (OR 2.16, 95% CI: 1.55-3.01). The risk of all-site cancer was higher in azoospermic men compared to oligospermic (OR 2.16, 95% CI: 1.55-3.01) and normozoospermic (OR 2.18, 95% CI: 1.20-3.96). Only azoospermic men might be at higher risk of testicular cancer when compared to men with normal sperm concentration (OR 1.80, 95% CI: 1.12-2.89). LIMITATIONS Although our pooled analysis shows an increased risk of mortality and all-site cancer risk in azoospermic men, the results show a lack of evidence to suggest a higher risk of comorbidities in men with poor semen concentration. Given the limited available data, the nature of the studies, and the high risk of bias, the results should be interpreted with caution. There is not enough data to confirm the usability of semen analysis as a predictor of poor long-term health in men, especially within the general population. No funding was obtained for this study. A.M. has received funding from Merck Serono, Ferring, Gedeon Richter, Pharmasure, and Cook Medical to attend medical conferences; has been a participant in an advisory board for Ferring; and has given an invited lecture for a Merck Serono advisory board. S.N. has received funding for medical conference attendance from Ferring and Cook Medical. PROSPERO No. CRD42024507563.

Exploring the link between periodontal disease and sperm quality: a comprehensive systematic review study

Mortazavi V et al., 2025 · BMC Oral Health · Free full text on PubMed Central

Periodontal diseases are among the most prevalent oral health conditions globally, with evidence suggesting their systemic effects, including potential impacts on male reproductive health. Inflammation associated with periodontitis might interfere with spermatogenesis and alter sperm parameters such as count, motility, morphology, and DNA integrity. This systematic review aims to critically assess existing studies on the relationship between periodontal disease and sperm quality to delineate its clinical implications for male infertility. The research was registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the National Institute for Health Research (PROSPERO code: CRD420251005800). A comprehensive literature search was conducted across multiple databases, including PubMed, EMBASE, ProQuest, Scopus, Web of Science (WOS), and Google Scholar, up to September 2024. Inclusion criteria targeted human studies reporting associations between periodontal health and sperm quality parameters. To assess the quality of the included studies, the Newcastle-Ottawa Scale (NOS) was used. Data were synthesized qualitatively and analyzed for trends. Nine studies encompassing 1,386 participants were included. Evidence suggests a significant association between periodontitis and decreased sperm motility, abnormal morphology, and increased DNA fragmentation. However, findings on sperm count and concentration were inconsistent. Mechanistic pathways suggest that inflammatory cytokines and oxidative stress contribute to these disruptions. This review highlights the systemic implications of periodontal disease on male reproductive health. Given the global decline in male fertility, maintaining oral health may serve as an adjunct strategy in managing infertility. Future research should prioritize large-scale, longitudinal studies to establish causality and explore preventive interventions.

Semen Quality as a Predictor of Subsequent Morbidity: A Danish Cohort Study of 4,712 Men With Long-Term Follow-up

Latif T et al., 2017 · American journal of epidemiology

Semen quality has been suggested to be a biological marker of long-term morbidity and mortality; however, few studies have been conducted on this subject. We identified 5,370 men seen for infertility at Frederiksberg Hospital, Denmark, during 1977-2010, and 4,712 of these men were followed in the Danish National Patient Registry until first hospitalization, death, or the end of the study. We classified patients according to hospitalizations and the presence of cardiovascular disease, diabetes, testicular cancer, or prostate cancer. We found a clear association between sperm concentration below 15 million/mL and all-cause hospitalizations (hazard ratio = 1.5, 95% confidence interval: 1.4, 1.6) and cardiovascular disease (hazard ratio = 1.4, 95% confidence interval: 1.2, 1.6), compared with men with a concentration above 40 million/mL. The probabilities for hospitalizations were also higher with a low total sperm count and low motility. Men with a sperm concentration of 195-200 million/mL were, on average, hospitalized for the first time 7 years later than were men with a sperm concentration of 0-5 million/mL. Semen quality was associated with long-term morbidity, and a significantly higher risk of hospitalization was found, in particular for cardiovascular diseases and diabetes mellitus. Our study supports the suggestion that semen quality is a strong biomarker of general health.