Cigarette Smoking and Semen Quality: A New Meta-analysis Examining the Effect of the 2010 World Health Organization Laboratory Methods for the Examination of Human Semen

Male Infertility: New Developments, Current Challenges, and Future Directions

There have been many significant scientific advances in the diagnostics and treatment modalities in the field of male infertility in recent decades. Examples of these include assisted reproductive technologies, sperm selection techniques for intracytoplasmic sperm injection, surgical procedures for sperm retrieval, and novel tests of sperm function. However, there is certainly a need for new developments in this field. In this review, we discuss advances in the management of male infertility, such as seminal oxidative stress testing, sperm DNA fragmentation testing, genetic and epigenetic tests, genetic manipulations, artificial intelligence, personalized medicine, and telemedicine. The role of the reproductive urologist will continue to expand in future years to address different topzics related to diverse questions and controversies of pathophysiology, diagnosis, and therapy of male infertility, training researchers and physicians in medical and scientific research in reproductive urology/andrology, and further development of andrology as an independent specialty.

Idiopathic secondary azoospermia occurrence in men with oligospermia over time

PURPOSE

To investigate the occurrence of idiopathic secondary azoospermia (ISA) in men with oligospermia over time and identify risk factors for ISA in this population.

METHODS

This was a retrospective cohort study conducted in a university-affiliated male infertility clinic. A total of 1056 oligospermic men (concentration < 15 million/ml (M/ml) and no azoospermia) with at least two SA done between 2000 and 2019 were included. The primary outcome was the occurrence of ISA by oligospermia severity.

RESULTS

In the entire cohort, 31 patients (2.9%) eventually became azoospermic with time. The ≤ 1 M/ml extremely severe oligospermia (ESO) group (283 patients) had significantly higher rates of ISA in each time period compared to the 1-5 M/ml severe oligospermia (SO) (310 patients) and 5-15 M/ml mild oligospermia (MO) (463 patients) groups (p < 0.05 for all comparisons), with rates of 21.1% in the ESO, 4.8% in the SO, and 0% in the MO group (p = 0.02) after 3-5 years, reaching 32% after 5 years in the ESO group compared to no cases in the other two groups (p = 0.006). Parameters shown to predict ISA were initial concentration < 1 M/ml (OR 22.12, p < 0.001) and time interval of > 3 and 5 years (OR 4.83 and 6.84, p = 0.009 and < 0.001, respectively), whereas testosterone levels were negatively associated with ISA (OR 0.88, p = 0.03).

CONCLUSIONS

Men with ≤ 1 M/ml, especially those with low testosterone levels, have a dramatically increased chance of becoming azoospermic with time. Therefore, sperm banking should be recommended in these cases. Men with a sperm concentration above 1 M/ml have low chances of becoming azoospermic, even after 3 or more years.

Australasian recurrent pregnancy loss clinical management guideline 2024, part II

Part II of the Australasian guideline for the investigation and management of recurrent pregnancy loss (RPL) provides evidence-based guidance on the management of RPL provided. The implications of inherited and acquired thrombophilia with respect to RPL and suggestions for clinical management are provided. Autoimmune factors, including human leukocyte antigen, cytokines, antinuclear antibodies and coeliac antibodies, and guidance for management are discussed. Infective, inflammatory and endometrial causes of RPL are discussed in detail. Environmental and lifestyle factors, male factor and unexplained causes are outlined. Levels of evidence and grades of consensus are provided for all evidence-based statements.

Impact of coenzyme Q10 as an adjuvant therapy to letrozole on spermiogram results and sex hormone levels in Iraqi men with infertility; randomized open label comparative study

Background: Worldwide, infertility affects about 15% of reproductive-age couples. In many cases, infertility can't be treated, however new treatment options with promising value have been involved in recent clinical trials. The aim of this clinical trial was to evaluate the impacts of adding coenzyme Q10 (CoQ10) to letrozole on the results of spermiogram and sex hormone tests in men diagnosed with idiopathic oligoasthenoteratozoospermia (iOAT) syndrome, which is a type of male defective spermatogenesis of unknown etiology. Methods: This randomized, open-label, parallel two-arm interventional study included 67 adult male patients aged 18-60 years with a confirmed diagnosis of iOAT syndrome recruited from The High Institute for Infertility Diagnosis & Assisted Reproduction Technologies/Nahrain University. Patients were randomly separated into two groups, Group A included 29 patients treated with letrozole 2.5 mg tablet orally twice a week, Group B included 38 patients treated with a combination of letrozole 2.5 mg tablet orally twice a week plus CoQ10 400 mg per day. Both groups completed treatment for three months. Semen samples, serum follicle-stimulating hormone (FSH), estradiol (E 2), and testosterone (T) were analyzed at day one, and at the end of month one, two and three. Results: Both groups showed that sperm concentration, normal morphology, total sperm count and motility, serum testosterone and FSH levels, and T/E 2 ratio were significantly increased, while estradiol levels significantly decreased after three months of treatment. Seminal fluid volume changed significantly in group A only. In comparing between the two groups, all measured parameters, apart from sperm motility and FSH level, demonstrated a significant difference after three months of treatment, while sperm volume reached significant value after only two months of therapy. Conclusions: CoQ10 as adjuvant treatment to letrozole effectively improved most of the tested sperm parameters in Iraqi men with iOAT. Registration: ClinicalTrials.gov ( NCT05847257, May 6, 2023).

Factors influencing natural fecundity in fertile couples: a survey of puerperae and their partners

RESEARCH QUESTION

What is the fecundity rate among fertile couples, and which factors influence it?

DESIGN

Retrospective study of all puerperae attending Cruces University Hospital Human Reproduction Unit over 9 months. An anonymous questionnaire was circulated to all patients, and 2510 valid completed questionnaires were collected. The main inclusion criterion was natural conception resulting in delivery. Pregnancies resulting from ART and contraceptive method failure were excluded. Investigated parameters were time to pregnancy, age and smoking (in women and men), previous pregnancies and intercourse frequency. A mathematical formula was developed to predict the per-month fecundity rate (PMFR).

RESULTS

The cumulative fecundity rate was 29.08%, 54.26%, 68.61%, 89.88%, 96.95% and 98.63% (at 1, 3, 6, 12, 24 and 36 months); between 12 and 36 months, the average PMFR ranged from 8.53-7.48%. Only 1.68% of pregnancies occurred between 24 and 36 months, and only 1.37% thereafter. The best fecundity markers were obtained in the group who had sexual intercourse seven to eight times a week. Women and men younger than 25 years had lower fecundity markers than those aged between 25 and 40 years.

CONCLUSIONS

Fertile couples have a non-negligible per-month fecundity rate between 12 and 36 months, which should be considered when planning fertility studies. The lower fecundity rate observed in women and men aged younger than 25 years deserves more study. Coital frequencies of more than two or three times a week did not affect the fecundity rate and was better with frequencies of seven to eight times a week.

Genetically predicted asthma and the risk of abnormal spermatozoa

Background

Several previous animal and human studies have found a strong association between asthma and spermatozoa quality, but whether these associations are causal or due to bias remains to be elucidated.

Methods

We performed a two-sample Mendelian randomization (MR) analysis to assess the causal effect of genetically predicted asthma on the risk of abnormal spermatozoa. Asthma, childhood-onset asthma (COA), and adult-onset asthma (AOA) (sample sizes ranging from 327,670 to 408,442) were included as the exposures. Genetic information for abnormal spermatozoa was obtained from a genome-wide association study (GWAS) comprising 209,921 participants. In univariable MR (UVMR) analysis, the inverse variance weighted (IVW) method was conducted as the primary method, with the MR Egger and weighted median used as supplementary methods for causal inference. Sensitivity analyses, including the Cochran Q test, Egger intercept test, MR-PRESSO, and leave-one-out analysis, were performed to verify the robustness of the MR results. Multivariable MR (MVMR) was conducted to evaluate the direct causal effects of asthma on abnormal spermatozoa risk.

Results

UVMR detected causal associations between genetically predicted asthma and an increased risk of abnormal spermatozoa (OR: 1.270, 95% CI: 1.045-1.545, p = 0.017). Moreover, we found that AOA (OR: 1.46, 95% CI: 1.051, 2.018, p = 0.024) has positive causal effects on the risk of abnormal spermatozoa rather than COA (p = 0.558). Sensitivity analysis found little evidence of bias in the current study (p > 0.05). MVMR further confirmed that asthma directly affected the risk of abnormal spermatozoa.

Conclusion

Our MR study suggested that genetically predicted asthma could be associated with an increased risk of abnormal spermatozoa, and similar results were obtained in AOA. Further studies are warranted to explain the underlying mechanisms of this association and may provide new avenues for prevention and treatment.

A metabolomic perspective on the mechanisms by which environmental pollutants and lifestyle lead to male infertility

The incidence of male infertility (MI) is rising annually. According to epidemiological studies, environmental pollution (e.g., organic, inorganic, and air pollutants), occupational exposure (e.g., high temperature, organic solvents, and pesticides), and poor lifestyle (e.g., diet, sleep, smoking, alcohol consumption, and exercise) are important non-genetic causative factors of MI. Due to multiple and complex causative factors, the dose-effect relationship, and the uncertainty of pathogenicity, the pathogenesis of MI is far from fully clarified. Recent data show that the pathogenesis of MI can be monitored by the metabolites in serum, seminal plasma, urine, testicular tissue, sperm, and other biological samples. It is considered that these metabolites are closely related to MI phenotypes and can directly reflect the individual pathological and physiological conditions. Therefore, qualitative and quantitative analysis of the metabolome, the related metabolic pathways, and the identification of biomarkers will help to explore the MI-related metabolic problems and provide valuable insights into its pathogenic mechanisms. Here, we summarized new findings in MI metabolomics biomarkers research and their abnormal metabolic pathways triggered by the presented non-genetic risk factors, providing a metabolic landscape of semen and seminal plasma in general MI patients. Then, we compared the similarities and differences in semen and seminal plasma biomarkers between MI patients exposed to environmental and poor lifestyle factors and MI patients in general, and summarized some common biomarkers. We provide a better understanding of the biological underpinnings of MI pathogenesis, which might offer novel diagnostic, prognostic, and precise treatment approaches to MI.

Intra-individual changes in sperm parameters and total motile count with time among infertile men

BACKGROUND

Paternal age association with sperm parameters has been previously studied, demonstrating a decrease in semen volume, sperm motility, and sperm morphology, but not in sperm concentration. However, scarce data exists on the individual intra-personal changes in semen parameters with time.

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate the changes in semen parameters and total motile count of infertile men over time.

MATERIALS AND METHODS

In this retrospective cohort study, infertile men without known risk factors for sperm quality deterioration and at least two semen analyses done > 3 months apart, between 2005 and 2021, were evaluated. Allocation to groups was according to time between first and last semen analyses - 3-12 months, 1-3 years, 3-5 years, and > 5 years. Basic characteristics and first and last semen analyses were compared. The primary outcome was the change in sperm parameters and the secondary outcome was the occurrence of a total motile count < 5 million in men with an initial total motile count > 10 million.

RESULTS

A total of 2018 men were included in the study. The median age at first semen analyses was 36.2 (interquartile range: 32.8-40.1) years and the median time between semen analyses was 323 days (range 90-5810 days). The overall trend demonstrated an increase in concentration in the 3-12 months and the 1-3 years groups, whereas volume, motility, and morphology remained similar in these time groups. Semen analyses done more than 5 years apart showed decreased volume (p < 0.05), motility (p < 0.05) morphology (p < 0.05), and steady sperm concentration. Significant declines in TMCs were found over time (p < 0.001), with 18% and 22% of infertile men with an initial total motile count > 10 million dropping to < 5 million after 3 and 5 years, respectively. The factors independently predictive of total motile count < 5 M in the last semen analyses in men with an initial total motile count of > 10 M in a multivariate logistic regression model were baseline volume (odds ratio 0.80, p = 0.03), baseline total motile count (odds ratio 0.98, p = 0.01) and time between semen analyses - 3-5 years (odds ratio 3.79, p < 0.001) and > 5 years (odds ratio 3.49, p = 0.04) DISCUSSION: Our study demonstrates, at the individual level, that while improvement in sperm concentration is observed in the first year and between 1 and 3 years, possibly due to fertility treatments, fertility-related counseling, and lifestyle changes, semen parameters decline with time over 3 years in individuals. Of significance, close to 22% of men with an initial total motile count > 10 million (a range where spontaneous pregnancy is attainable) declined to < 5 million (a range usually indicating a need for in-vitro fertilization/intracytoplasmic sperm injection) over 5 years. This data could contribute to individualized family planning for infertile men regarding the mode and timing of conception and the need for sperm banking, in order to minimize the need for future fertility treatments.

Influence of substance use on male reproductive health and offspring outcomes

The prevalence of substance use globally is rising and is highest among men of reproductive age. In Africa, and South and Central America, cannabis use disorder is most prevalent and in Eastern and South-Eastern Europe, Central America, Canada and the USA, opioid use disorder predominates. Substance use might be contributing to the ongoing global decline in male fertility, and emerging evidence has linked paternal substance use with short-term and long-term adverse effects on offspring development and outcomes. This trend is concerning given that substance use is increasing, including during the COVID-19 pandemic. Preclinical studies have shown that male preconception substance use can influence offspring brain development and neurobehaviour through epigenetic mechanisms. Additionally, human studies investigating paternal health behaviours during the prenatal period suggest that paternal tobacco, opioid, cannabis and alcohol use is associated with reduced offspring mental health, in particular hyperactivity and attention-deficit hyperactivity disorder. The potential effects of paternal substance use are areas in which to focus public health efforts and health-care provider counselling of couples or individuals interested in conceiving.

In-Vitro Effects of Perfluorooctanoic Acid on Human Sperm Function: What Are the Clinical Consequences?

Background: Lifestyle and environmental pollution harm male fertility. Perfluoroalkyl substances (PFAS) are bio-accumulates in the environment as well as in several human tissues, and one of the most common PFAS is perfluorooctanoic acid (PFOA). Therefore, this study aimed to evaluate the in vitro effects of PFOA with hydrophobic and waterproofing properties on motility and bio-functional sperm parameters. Methods: To accomplish this, 50 healthy men with normozoospermia and not exposed to high doses of PFAS were enrolled. Their spermatozoa were incubated for 3 h with increasing concentrations of PFOA (0, 0.01, 0.1, and 1 mM) to evaluate its effects. In particular, we evaluated the effects of PFOA on total and progressive sperm motility and, by flow cytometry, on the following bio-functional sperm parameters: degree of chromatin compactness, viability, early and late apoptosis, mitochondrial membrane potential, the degree of lipoperoxidation, and concentrations of mitochondrial superoxide anion. Results: The results showed that PFOA decreased both total and progressive sperm motility, impaired chromatin compactness, and increased sperm lipid peroxidation and mitochondrial superoxide anion levels. Conclusions: This study showed that PFOA alters several sperm parameters and thus it may play a negative role in male fertility.

Tobacco or marijuana use and infertility: a committee opinion

In the United States, approximately 21% of adults report some form of tobacco use, although 18% report marijuana use. Although the negative impact of tobacco use in pregnancy is well documented, the impact of tobacco and marijuana on fertility and reproduction is less clear. This committee opinion reviews the potential deleterious effects of tobacco, nicotine, and marijuana use on conception, ovarian follicular dynamics, sperm parameters, gamete mutations, early pregnancy, and assisted reproductive technology outcomes. It also reviews the current status of tobacco smoking cessation strategies. This document replaces the 2018 American Society for Reproductive Medicine Practice Committee document entitled Smoking and Infertility: a committee opinion (Fertil Steril 2018).

Fabrication strategies for chiral self-assembly surface

Chiral self-assembly is the spontaneous organization of individual building blocks from chiral (bio)molecules to macroscopic objects into ordered superstructures. Chiral self-assembly is ubiquitous in nature, such as DNA and proteins, which formed the foundation of biological structures. In addition to chiral (bio) molecules, chiral ordered superstructures constructed by self-assembly have also attracted much attention. Chiral self-assembly usually refers to the process of forming chiral aggregates in an ordered arrangement under various non-covalent bonding such as H-bond, π-π interactions, van der Waals forces (dipole-dipole, electrostatic effects, etc.), and hydrophobic interactions. Chiral assembly involves the spontaneous process, which followed the minimum energy rule. It is essentially an intermolecular interaction force. Self-assembled chiral materials based on chiral recognition in electrochemistry, chiral catalysis, optical sensing, chiral separation, etc. have a broad application potential with the research development of chiral materials in recent years.

Cross sectional study on exposure to BPA and its analogues and semen parameters in Czech men

Exposure to bisphenols has been found to have adverse effects on male reproductive function in animals. Human exposure to bisphenols is widespread. Bisphenol A (BPA) and its analogues, including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF) are utilized in various consumer products such as food contact materials and dental resins. The effects of these compounds on male fertility and spermatogenesis are unclear and findings from human studies are inconsistent. In this cross-sectional study, we evaluated the influence of BPA, BPS, BPF, BPAF (BPs) measured in semen on number of spermatozoa, total motility, progressive motility, morphology, and DNA fragmentation. We also examined the association of bisphenols (BPs) exposure with patients' occupation. A total of 358 patients aged 17-62 years with BMI 18-42 were included in the study from 2019 to 2021. BPs were extracted using solvent extraction followed by preconcentration step and determined by high-performance liquid chromatography and tandem mass spectrometry (LC/MSMS). Bisphenols were detected in 343 from 349 analysed samples (98.3% of all the samples). In 6 samples, the concentration of all BPs was under the limit of detection and in 20 samples under the limit of quantification. We did not find a statistically significant relationship between occupation and BPs. However, we observed significant correlations between the concentration of BPA and a lower motility and normal morphology. For BPS, a significant correlation with a lower ejaculate volume and a lower total sperm count was found. BPF and BPAF were detected only in 14.3% and 23.9% of samples, respectively. For BPF and BPAF, no significant correlations with spermiogram parameters were observed. Our results show that BPs are widespread in the male population (more than 90% of analysed samples), independently of an occupation and in case of BPA and BPS having a negative impact on spermiogram parameters.

Exploration of Lactiplantibacillus plantarum P101 ameliorated the alcohol-induced testicular dysfunction based on metabolome analysis

The decline in male sperm quality caused by multiple factors has become a widespread concern. Alcohol excessive consumption is one of the factors that induce testicular dysfunction. Testicular dysfunction caused by alcohol abuse is related to oxidative stress and inflammation. Probiotics can ameliorate alcohol-induced testicular dysfunction. However, the specific mechanism is not explicit. This study aimed to elucidate the underlying mechanism by which Lactiplantibacillus plantarum P101 ameliorates the alcohol-induced testicular dysfunction. The model of alcohol-induced testicular dysfunction in C57B/6 male mice was established according to the National Institute on Alcohol Abuse and Alcoholism, and Lactiplantibacillus plantarum P101 supplementation was orally administered to mice during the experiment. The results showed that Lactiplantibacillus plantarum P101 promoted androgen production, reduced testis inflammation, and improved testis antioxidant capacity, thereby improving sperm quality and sperm motility and ultimately ameliorating alcohol-induced testicular disorder. Three key metabolite pathways and six key metabolites were identified by metabolome analysis.

Mediation of association between semen microcystin exposure and semen quality by sex hormones in Chinese men

Numerous studies have shown microcystins (MCs) inducing male reproductive toxicity, but the underlying mechanisms in humans are unclear. Therefore, this study aimed to evaluate the mediating role of serum sex hormones in the association between MC exposure and semen quality. In this study, we measured the levels of semen MCs and serum sex hormones in Chinese men [sample 1 (n = 649); sample 2 (n = 924)]. The results showed that there was a non-significant dose-dependent relationship between semen MCs and semen volume reduction (p for trend = 0.079) in sample 1, and semen MCs were significantly negatively associated with total motility, progressive motility, curvilinear velocity, mean angular displacement and acrosome integrity (p < 0.05) in sample 2. We also found that semen MCs were significantly positively associated with serum follicle stimulating hormone (FSH) (β = 0.151; 95% CI: 0.065, 0.236), but negatively associated with serum inhibin B (INHB) (β = -0.605; 95% CI: -0.944, -0.265), and these linear associations were confirmed in restricted cubic spline (RCS) models (all pnon-linearity > 0.1). Furthermore, mediation analysis revealed that serum INHB mediated 19.86% of the adverse effect of MC exposure on acrosome integrity. In conclusion, this study reveals the mediating roles of serum sex hormones in the relationship between MC exposure and decreased semen quality in men.

Association between diurnal temperature range and sperm quality: Evidence from a prospective cohort in Central China

Inter-day temperature variability has been reported to be associated with sperm quality in a city-level exposure assessment study. However, studies exploring the impact of temperature variability within a single day on sperm quality at individual level are still lacking. The present study aims to bridge this research gap by analyzing the linear and non-linear associations between diurnal temperature range (DTR) exposure and sperm quality, utilizing data from the Anhui Prospective Assisted Reproduction Cohort. The study included 15,112 males (totaling 28,267 tests) and assessed individual exposure to various environmental factors (residential greenness, ambient particulate matter, sulfur dioxide, relative humidity, ambient temperature, and DTR) during the 0-90 day period before semen analysis. A combination of a linear mixed model, natural cubic splines, and subgroup analysis was employed. Significant "U"-shaped non-linear associations were observed between DTR exposure and total motility, sperm concentration, sperm count, total motile sperm count, and progressive motile sperm count. Lower DTR levels negatively impacted these parameters, whereas higher DTR levels showed a positive effect. Notably, these associations were more pronounced at ambient temperatures below 16.5 °C, while absent in warmer conditions. Sperm quality demonstrates increased sensitivity to DTR exposure in cooler environments. Therefore, implementing effective individual temperature management strategies is crucial for mitigating decreased sperm quality associated with DTR exposure, highlighting the potential benefits of government policies aimed at achieving carbon neutrality to enhance overall sperm quality in the general population.

Associations of exposure to ambient fine particulate matter constituents from different pollution sources with semen quality: Evidence from a prospective cohort

The association between ambient fine particulate matter (PM2.5) exposure and semen quality remains inconclusive, possibly due to variations in pollution sources and PM2.5 compositions. Studies investigating the constituents of PM2.5 have been hindered by small sample sizes, and research exploring the relationships between PM2.5 pollution sources and semen quality is lacking. To address this gap, we conducted a comprehensive study based on the Anhui prospective assisted reproduction cohort to evaluate the associations between semen quality and the constituents and pollution sources of PM2.5. This study included 9013 semen samples from 4417 males in the urban districts of Hefei. The median concentrations of PM2.5 constituents, including eight metals and four water-soluble ions (WSIs), were measured for seven days per month at two monitoring stations during the 0-90-day exposure window. A linear mixed-effects model, weighted quantile sum regression, and positive matrix factorisation were used to evaluate the associations of the constituents and pollution sources of PM2.5 with semen quality. The results showed that exposure to PM2.5-bound metals (antimony, arsenic, cadmium, lead, and thallium) and WSIs (sulphate and chloride) were negatively associated with semen quality parameters. Moreover, mixtures of PM2.5-bound metals and WSIs were negatively associated with semen quality. Additionally, PM2.5 derived from traffic emissions was negatively associated with semen quality. In summary, our study revealed that ambient PM2.5 and its constituents, especially metals, were negatively associated with semen quality. Antimony, lead, and thallium emerged as the primary contributors to toxicity, and PM2.5 from traffic emissions was associated with decreased semen quality. These findings have important public health implications for the management of PM2.5 pollution in the context of male reproductive health.

Decrease in Sperm Parameters in the 21st Century: Obesity, Lifestyle, or Environmental Factors? An Updated Narrative Review

Semen quality represents a compelling factor for fertility, and delineating the normal values has proven difficult. In the last four decades, several authors have reported a noticeable decline in sperm parameters. Also, studies investigating 'time to pregnancy' have shown that fecundity begins to be reduced when sperm numbers decrease below 30 million, even though according to the 6th edition of the WHO manual, the normal value is currently 16 million/mL or 39 million per ejaculate. There exists sufficient data to suggest a decline in sperm counts over time, even though the clear reason for this adverse trend is not well established, but some associations have been hypothesised, such as maternal smoking during pregnancy. Additional potential factors have yet to be fully illustrated but involve poor diet, increased obesity, and exposure to environmental toxins. Moreover, the change in environmental conditions and more common exposure to endocrine-disrupting chemicals (EDCs), such as pesticides and herbicides, as well as bisphenol A, phthalates, polychlorinated biphenyls, and heavy metals, starting from prenatal life and continuing into adulthood, may exhibit probable features explaining the reduction in sperm parameters. Therefore, the main goal of this narrative review is to furnish an overview of the possible effects of exposure to EDCs on testicular function and spermatogenesis and, also, to summarise the evidence regarding a decrease in sperm quality and examine its potential consequences.

Temporal Trends in Semen Quality, Hormone Levels, and Substance Use Among Infertile Men in Pre- and Post-Cannabis Legalization Eras in Canada

Background: The Cannabis Act (Bill C-45) was enacted in 2018, to legalize and regulate the use, production, and sale of nonmedical cannabis in Canada. While public health and safety implications of cannabis legalization have yet to be elucidated, the wide availability of cannabis necessitates health care providers to be knowledgeable about therapeutic potential and side effects of use. This study aimed to examine the temporal trends over two decades and the impact of the Cannabis Act in Canada, implemented in October 2018, on substance use, semen parameters, and testosterone levels of infertile men. Methods: We conducted a retrospective cohort study from a prospectively maintained database of a single infertility clinic. Demographic, fertility, and substance use history were correlated with semen and hormone assessments. Temporal trends in cannabis use and semen quality between 2001 and 2021 were investigated and compared between pre-cannabis legalization eras (PRCL) and post-cannabis legalization eras (POCL). Results: Our cohort included 11,630 patients (9411 PRCL and 2230 POCL). Cannabis use increased by 8.4% per year (p<0.001), while alcohol and tobacco consumption declined (0.8% and 1.5% per year, p<0.05 and p=0.004, respectively). Similar trends were noticed in the POCL, with higher rates of cannabis use (22.4% vs. 12.9%, p<0.001) and decreased tobacco and alcohol intake (15.2% vs. 17.7%, p=0.005 and 50.5% vs. 55.2%, p<0.001, respectively) compared to the PRCL group. Semen concentration was lower in the POCL group (24.8±44.8 vs. 28.7±48.3 million/mL, p=0.03). Testosterone did not differ between the cohorts. Comparison between cannabis users (n=1715) and nonusers (n=9924) demonstrated a slight increase in sperm motility (25.9%±15.3% vs. 23.9%±15.0%, p=0.002) and decreased sperm concentration among users (27.6±53.5 vs. 23.9±15.0 million/mL, p=0.03). Conclusion: A nearly 10% rise in cannabis use in the POCL era was observed among men being investigated for infertility. Our data suggest cannabis use may be associated with an increase in testosterone, slightly improved sperm motility, and decreased sperm concentration.

Temporal Trends of Semen Quality and Fertility Rates Over the Course of a Decade: Data From King County, Washington

OBJECTIVE

There has been a widely reported decline in both semen quality and fertility rate, however to date these studies have not looked at a decline of both in the same time period within the same geographical area. The objective of this study was to determine if there existed a temporal trend in both semen parameters and fertility rates for the same geographic area (King County, WA) over time.

MATERIALS AND METHODS

Semen parameters from sperm donors at Seattle sperm bank were obtained from 2008 to 2021. Sperm donations occurred in King County, WA. Donors were from within 50 miles of the donation site. Fertility rates were calculated for King County, WA using census data from SEER to find number of women aged 15-49 and the number of births were found using CDC Wonder data from 2006 to 2017.

RESULTS

There were a total of 76,622 sperm donor semen analyses from King County, WA included in our study from 2008 to 2021. The fertility rate for King County, WA was calculated from 2006 to 2017. From 2008 to 2021, there was a statistically significant decline in semen quality over time for both sperm count (P < .01), total motile sperm count (P < .01), sperm concentration (P < .01), and progressive motility (P < .01). Additionally, from 2006 to 2017 there was a statistically significant decline in fertility rate (P < .01).

CONCLUSION

We report a statistically significant decline in sperm parameters among donors and a corresponding decline in fertility rates from the same geographic area that warrants further investigation given the serious societal and economic impacts a shrinking population presents. While certainly not the sole contributing factor, declining sperm parameters likely need to be accounted for when accounting for declining fertility rates.

Effect of Male Cigarette Smoking on In Vitro Fertilization (IVF) Outcomes and Embryo Morphokinetic Parameters

This retrospective cohort study examines the association between male smoking status and embryo development in vitro. The study included non-smoking women aged under 40 years who underwent in vitro fertilization (IVF) at Yanaihara Women's Clinic from May 2019 to May 2022, and they were divided into two groups according to the husband's smoking status. The effect of male smoking status on IVF outcomes was compared retrospectively based on embryonic development using a time-lapse incubator. A total of 184 patients were included; 272 oocytes of 45 female non-smokers were cultured with the sperm of male smokers, and 816 oocytes of 139 female non-smokers were cultured with the sperm of male non-smokers. No significant differences were observed between male smokers and non-smokers groups with regard to fertilization and the top-quality embryo on day 3 and day 5 (p > 0.05). The male smoker group's embryos reached the early cleavage-stage parameters (time of pronuclei appearance to the five-cell stage) significantly earlier than the male non-smoker group's embryos (p < 0.05). However, no significant differences were observed between the two groups in other parameters of top-quality blastocysts (p > 0.05). It was concluded that male smoking has some differences on the timing of early embryonic events on time-lapse examination.

Sperm morphology: Evaluating its clinical relevance in contemporary fertility practice

Background

The World Health Organization (WHO) recommends reporting sperm morphology in a standard semen analysis. However, the clinical utility and prognostic value of morphology is often debated.

Methods

We reviewed and summarized studies that assessed both the benefits and limitations of sperm morphology in the context of natural fertility, assisted reproductive technologies, and recurrent pregnancy loss. We additionally describe possible environmental and anatomical etiologies of teratozoospermia.

Results

Sperm morphology evaluation has continuously evolved since the release of the first WHO manual in 1980. Initially, several large studies reported significant inverse associations between fertility outcomes and teratozoospermia. Most recent studies, however, fail to show an association between sperm morphology and natural or assisted fertility outcomes.

Conclusion

Sperm morphology analysis may have limited diagnostic and prognostic value. Providers should be aware of these limitations when counseling or managing infertile patients.

Implications of Exposure to Air Pollution on Male Reproduction: The Role of Oxidative Stress

Air pollution, either from indoor (household) or outdoor (ambient) sources, occurs when there is presence of respirable particles in the form of chemical, physical, or biological agents that modify the natural features of the atmosphere or environment. Today, almost 2.4 billion people are exposed to hazardous levels of indoor pollution, while 99% of the global population breathes air pollutants that exceed the World Health Organization guideline limits. It is not surprising that air pollution is the world's leading environmental cause of diseases and contributes greatly to the global burden of diseases. Upon entry, air pollutants can cause an increase in reactive oxygen species (ROS) production by undergoing oxidation to generate quinones, which further act as oxidizing agents to yield more ROS. Excessive production of ROS can cause oxidative stress, induce lipid peroxidation, enhance the binding of polycyclic aromatic hydrocarbons (PAHs) to their receptors, or bind to PAH to cause DNA strand breaks. The continuous and prolonged exposure to air pollutants is associated with the development or exacerbation of pathologies such as acute or chronic respiratory and cardiovascular diseases, neurodegenerative and skin diseases, and even reduced fertility potential. Males and females contribute to infertility equally, and exposure to air pollutants can negatively affect reproduction. In this review, emphasis will be placed on the implications of exposure to air pollutants on male fertility potential, bringing to light its effects on semen parameters (basic and advanced) and male sexual health. This study will also touch on the clinical implications of air pollution on male reproduction while highlighting the role of oxidative stress.

Effect of smoking on methylation and semen parameters

One type of epigenetic modification is genomic DNA methylation, which is induced by smoking, and both are associated with male infertility. In this study, the relationship between smoking and CHD5 gene methylation and semen parameters in infertile men was determined. After the MS-PCR of blood in 224 samples, 103 infertile patients (62 smokers and 41 non-smokers) and 121 fertile men, methylation level changes between groups and the effect of methylation and smoking on infertility and semen parameters in infertile men were determined. The results showed that there is a significant difference in the methylation status (MM, MU, UU) of the CHD5 gene between the patient and the control group, and this correlation also exists for the semen parameters (p < .001). The average semen parameters in smokers decreased significantly compared to non-smokers and sperm concentration was (32.21 ± 5.27 vs. 55.27 ± 3.38), respectively. MM methylation status was higher in smokers (22.5%) compared to non-smokers (14.6%). Smoking components affect the methylation pattern of CHD5 gene, and smokers had higher methylation levels and lower semen parameters than non-smokers, which can be biomarkers for evaluating semen quality and infertility risk factors. Understanding the epigenetic effects of smoking on male infertility can be very useful for predicting negative consequences of smoking and providing therapeutic solutions.

Effect of obstructive sleep apnea on semen quality

BACKGROUND

Obstructive sleep apnea (OSA) has several notable complications such as hypertension and diabetes. Studies have also shown that OSA is associated with erectile dysfunction and reduced androgen levels. However, the effect of OSA on semen quality remains poorly studied.

METHODS

Men attending a tertiary reproductive center for semen analysis were tested with a portable sleep breathing monitor. Patients were divided into four groups based on their apnea hypopnea index: none, mild, moderate, and severe obstructive sleep apnea. Differences between groups were assessed using χ2, and associations were tested with multiple regression analysis.

RESULTS

We included a total of 175 male subjects with a mean age of 32.2 ± 3.6 years. There were significant differences between groups in progressive sperm motility (%) (43 ± 16, 42 ± 17, 36 ± 18, 29 ± 18, respectively; p = 0.002), total motility (%) (59 ± 19, 59 ± 20, 49 ± 21, 42 ± 20, respectively; p = 0.010), and vitality (%) (80 ± 10, 81 ± 11, 79 ± 8, 72 ± 19, respectively; p = 0.039). Asthenospermia (progressive motility < 35%) was significantly more common in subjects with OSA (χ2 = 5.195, p = 0.023). In multiple regression models, after adjusting for age and body mass index, apnea hypopnea index remained negatively and significantly associated with progressive motility, total motility, and vitality.

CONCLUSIONS

OSA is an independent risk factor for sperm motility and vitality, and further investigation is now needed to determine if continuous positive pressure ventilation or other therapies can improve semen quality in these patients.

Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats

Environmental hazards are an increasing concern due to the rapid pace of industrialization. Among these hazards, noise and carbon monoxide (CO) are common risk factors and have been shown to cause serious health problems. However, existing studies focused on the individual effects of noise and CO exposure and the combined effects of these two factors remain poorly understood. Our study aimed to examine the combined effects of noise and CO exposure on testicular function by constructing individual and combined exposure models. Our findings indicated that combined exposure to noise and CO was associated with a higher risk of testicular damage and male reproductive damage when compared to exposure alone. This was evidenced by poorer semen quality and more severe pathological damage to the testis. This combined exposure led to higher levels of oxidative stress and apoptosis in the testes, with bioinformatics analyses suggesting the signaling pathways involved in these responses. Specifically, activation of the P53 signaling pathway was found to contribute to the testicular damage caused by the combined exposure. Encouragingly, pterostilbene (PTE), a novel phytochemical, alleviated combined exposure-induced testicular damage by reducing oxidative stress and germ cell apoptosis. Overall, we identified joint reproductive toxicity resulting from the exposure to noise and CO, and found that PTE is a promising potential treatment for injuries caused by these factors. The cover image is based on the Research Article Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats by Yingqing Li et al., https://doi.org/10.1002/tox.23927.

Deafening Silence of Male Infertility

Think about 6 loved ones of reproductive age in your life. Now imagine that 1 of these 6 individuals is suffering from infertility. Perhaps they feel alone and isolated, unable to discuss their heartbreak with their closest friends, family, and support network. Suffering in silence. In this editorial, we discuss the infertility journey through the lens of the patients, the providers, and the scientists who struggle with infertility each and every day. Our goal is to open a dialogue surrounding infertility, with an emphasis on dismantling the longstanding societal barriers to acknowledging male infertility as a disease. Through education, communication, compassion, and advocacy, together we can all begin to break the deafening silence of male infertility.

Male Factor Infertility: What Every OB/GYN Should Know

Male factor infertility plays a role in approximately 30% of infertility cases. Various causes of male factor infertility exist including congenital, acquired, idiopathic, or environmental factors. Identifying the underlying etiology of male factor infertility is a key step toward providing appropriate counseling, effective treatment options, and improving outcomes for couples with infertility. Although the recent advances and developments in assisted reproductive technology have undoubtedly improved fertility outcomes, clinicians must understand the scope of reproductive urologists in the evaluation and treatment of male infertility to provide comprehensive counseling, appropriate referral, comprehensive evaluation, and correct surgical sperm retrieval techniques when needed.

Association between self-reported mobile phone use and the semen quality of young men

OBJECTIVES

To investigate the association between mobile phone exposure and semen parameters.

DESIGN

A nationwide cross-sectional study.

SETTING

Andrology laboratories in close proximity to 6 army recruitment centers.

PATIENTS

In total, 2886 men from the general Swiss population, 18-22 years old, were recruited between 2005 and 2018 during military conscription.

INTERVENTION

Participants delivered a semen sample and completed a questionnaire on health and lifestyle, including the number of hours they spent using their mobile phones and where they placed them when not in use.

MAIN OUTCOME MEASURES

Using logistic and multiple linear regression models, adjusted odds ratios and β coefficients were determined, respectively. The association between mobile phone exposure and semen parameters such as volume, sperm concentration, total sperm count (TSC), motility, and morphology was then evaluated.

RESULTS

A total of 2759 men answered the question concerning their mobile phone use, and 2764 gave details on the position of their mobile phone when not in use. In the adjusted linear model, a higher frequency of mobile phone use (>20 times per day) was associated with a lower sperm concentration (adjusted β: -0.152; 95% confidence interval: -0.316; 0.011) and a lower TSC (adjusted β: -0.271; 95% confidence interval: -0.515; -0.027). In the adjusted logistic regression model, this translates to a 30% and 21% increased risk for sperm concentration and TSC to be below the World Health Organization reference values for fertile men, respectively. This inverse association was found to be more pronounced in the first study period (2005-2007) and gradually decreased with time (2008-2011 and 2012-2018). No consistent associations were observed between mobile phone use and sperm motility or sperm morphology. Keeping a mobile phone in the pants pocket was not found to be associated with lower semen parameters.

CONCLUSION

This large population-based study suggests that higher mobile phone use is associated with lower sperm concentration and TSC. The observed time trend of decreasing association is in line with the transition to new technologies and the corresponding decrease in mobile phone output power. Prospective studies with improved exposure assessment are needed to confirm whether the observed associations are causal.

Association of diet and lifestyle factors with semen quality in male partners of Chinese couples preparing for pregnancy

BACKGROUND

Semen quality significantly influences conception, and its preservation is crucial for couples seeking pregnancy. We investigated dietary and lifestyle risk factors impacting semen quality.

METHODS

A total of 466 males from the Guangzhou Women and Children's Medical Center's pre-pregnancy consultation clinic were recruited between January 2021 and March 2023 for inclusion. Semen analysis was performed, and diet and lifestyle data were gathered via questionnaire. Logistic regression was utilized to examine the link between diet, lifestyle variables, and semen quality.

RESULTS

Smoking worsened progressive sperm motility (38.0% vs. 36.0%, t = 2.262; P = 0.049). Alcohol consumption impaired progressive motility (40.5 ± 17.8% vs. 34.7 ± 16.1%, t = 3.396; P < 0.001) and total motility (56.0% vs. 64.0%; P = 0.001). Using plastic beverage bottles for oil or seasonings lowered sperm concentrations (40.4% vs. 59.0% vs. 65.5%; P = 0.032). A sweet diet correlated with higher total sperm motility (55.0% vs. 60.0%, 62.0% vs. 63.2%; P = 0.017). Higher milk product intake improved sperm concentration (41.6106 vs. 63.7106 vs. 66.1*106; P = 0.021) and motility (54.5% vs. 56.0% vs. 63.0%; P = 0.033). More frequent egg consumption increased semen volume (3.1 mL vs. 3.8 mL vs. 4.0 mL; P = 0.038). Roughage intake enhanced sperm concentration (160.8106 vs. 224.6106; P = 0.027), and adequate sleep improved progressive sperm motility rate (35.4% ± 18.2% vs. 40.2 ± 16.3%, F = 3.747; P = 0.024) and total motility (52.7% vs. 61.5%; P = 0.013). The regression model showed that using plastic containers for condiments was a protective factor for semen volume (OR: 0.12; CI 0.03-0.55; P = 0.006), sperm concentration (OR: 0.001, CI 0.00-0.30; P = 0.012), and count (OR: 0.12, CI 0.03-0.48; P = 0.003). Milk and egg consumption were also protective for semen volume (OR: 0.18, CI 0.06-0.51; P = 0.001 and OR: 0.11, CI 0.03-0.55; P = 0.006, respectively), while sufficient sleep benefitted total sperm motility (OR: 0.47, CI 0.24-0.95; P = 0.034).

CONCLUSIONS

Smoking and drinking, type of condiment container, diet preference, sleep duration, and milk, roughage, and egg consumption may reduce semen quality.

Determining the content and needs assessment a mobile-based self-care program in infertile men

BACKGROUND

Infertility is a public health problem in the world, using new technology, such as mobile phones, is increasing in the field of health. This study aimed to determine the Necessity of self-care training contents by performing a needs analysis among men with infertility problems to design a mobile phone-based application.

METHODS

Followed by reviewing the related literature, a questionnaire including 40 educational items and seven software features was designed in three general sections and distributed among 30 specialists in nutrition (n = 18) and infertility (n = 12). The validity of the questionnaire was confirmed by a panel of experts in nutrition, infertility, and medical informatics. The questionnaire's reliability was also corroborated by Cronbach's alpha of 86.4.

RESULTS

All items related to the software features and most items in the questionnaire were deemed necessary by participants. However, the items: "Occupation and history of chronic diseases" in the demographic information section and "Effects of infertility and food allergy" in the educational section were not confirmed.

CONCLUSION

The present findings could not only highlight the patients' roles in managing their disease but also increase the healthcare workers' awareness in designing the hospital information system.

Global, regional and national burden of male infertility in 204 countries and territories between 1990 and 2019: an analysis of global burden of disease study

BACKGROUND

Many countries and regions have experienced male fertility problems due to various influencing factors, especially in less developed countries. Unlike female infertility, male infertility receives insufficient attention. Understanding the changing patterns of male infertility in the world, different regions and different countries is crucial for assessing the global male fertility and reproductive health.

METHODS

We obtained data on prevalence, years of life lived with disability (YLD), age-standardized rates of prevalence (ASPR) and age-standardized YLD rate (ASYR) from the Global Burden of Disease Study 2019. We analyzed the burden of male infertility at all levels, including global, regional, national, age stratification and Socio-demographic Index (SDI).

RESULTS

In 2019, the global prevalence of male infertility was estimated to be 56,530.4 thousand (95% UI: 31,861.5-90,211.7), reflecting a substantial 76.9% increase since 1990. Furthermore, the global ASPR stood at 1,402.98 (95% UI: 792.24-2,242.45) per 100,000 population in 2019, representing a 19% increase compared to 1990. The regions with the highest ASPR and ASYR for male infertility in 2019 were Western Sub-Saharan Africa, Eastern Europe, and East Asia. Notably, the prevalence and YLD related to male infertility peaked in the 30-34 year age group worldwide. Additionally, the burden of male infertility in the High-middle SDI and Middle SDI regions exceeded the global average in terms of both ASPR and ASYR.

CONCLUSION

The global burden of male infertility has exhibited a steady increase from 1990 to 2019, as evidenced by the rising trends in ASPR and ASYR, particularly in the High-middle and Middle SDI regions. Notably, the burden of male infertility in these regions far exceeds the global average. Additionally, since 2010, there has been a notable upward trend in the burden of male infertility in Low and Middle-low SDI regions. Given these findings, it is imperative to prioritize efforts aimed at improving male fertility and reproductive health.

Unraveling the Impact of Sperm DNA Fragmentation on Reproductive Outcomes

In recent years, there has been a growing interest in identifying subcellular causes of male infertility, and sperm DNA fragmentation (SDF) research has been at the forefront of this focus. DNA damage can occur during spermatogenesis due to faulty chromatin compaction or excessive abortive apoptosis. It can also happen as sperm transit through the genital tract, often induced by oxidative stress. There are several methods for SDF testing, with the sperm chromatin structure assay, terminal deoxynucleotidyl transferase d-UTI nick end labeling (TUNEL) assay, comet assay, and sperm chromatin dispersion test being the most commonly used. Numerous studies strongly support the negative impact of SDF on male fertility potential. DNA damage has been linked to various morphological and functional sperm abnormalities, ultimately affecting natural conception and assisted reproductive technology outcomes. This evidence-based review aims to explore how SDF influences male reproduction and provide insights into available therapeutic options to minimize its detrimental impact.

Deteriorating Semen Quality: The Role of the Environment

Since the end of the last century, several reports have suggested that semen quality is declining, especially in Western countries. Furthermore, cross-sectional studies using similar protocols have suggested regional differences in semen quality of young and fertile men. Reasons for these regional differences and local adverse trends in semen quality are unknown, but environmental factors are suspected to have a role. Besides adulthood environmental exposures, those occurring during testicular development may also affect semen quality. Longitudinal follow-up studies and mixture risk analyses are needed to study the effect of fetal, childhood, and adult life environment on semen quality.

[Male infertility, environment and lifestyle]

BACKGROUND

Since the 1970s, there has been a quantitative and qualitative decline in sperm parameters. The main hypothesis to explain such a rapid evolution is the involvement of environmental and behavioral phenomena.

METHODS

A bibliographic search limited to English and French literature in men published before 7/2023 was carried out on the links between fertility and pollution, xenobiotics, tobacco, narcotics, cannabis, alcohol, weight, sport, sedentary lifestyle, sleep and anabolics.

RESULTS

Profound changes in lifestyle have occurred over the past 50 years: reduced sleep time, sedentary lifestyle, dietary changes, tobacco consumption, use of narcotics and anabolics. These changes have a proven impact on spermogram parameters, and should be corrected in an effort to optimize reproductive health. Other environmental parameters: pollution, exposure to heavy metals, exposure to xenobiotics, phthalates and pesticides… will be more difficult to exclude from patients' daily lives, but deserve to be taken more into account.

CONCLUSION

This review should help the urologist to assess and counsel patients in order to improve their reproductive health. These factors should be routinely investigated in infertile men.

Association between dietary total antioxidant capacity and semen quality among men attending an infertility clinic: a cross-sectional study

STUDY QUESTION

Is dietary non-enzymatic antioxidant capacity related to semen quality?

SUMMARY ANSWER

The only statistically significant association of semen quality parameters with dietary total antioxidant capacity (DTAC) detected was an inverse association between DTAC and ejaculate volume.

WHAT IS KNOWN ALREADY

Growing interest exists regarding the role of diet in influencing semen quality. While DTAC is linked to favorable health outcomes, its association with semen quality, especially among men attending infertility clinics, remains understudied.

STUDY DESIGN SIZE DURATION

This cross-sectional study was carried out between June and December of 2020. In total, 1715 participants were included in the final analysis.

PARTICIPANTS/MATERIALS SETTING METHODS

Men who attended an infertility clinic in China were enrolled. Experienced clinical technicians performed the semen analysis. The DTAC indices included the ferric-reducing ability of plasma, oxygen radical absorbance capacity, total reactive antioxidant potential, and Trolox equivalent antioxidant capacity. The quantile regression model was used for multivariate analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjustment for a variety of confounding variables, a significant inverse association was identified between DTAC and ejaculate volume (βcontinuous FRAP = -0.015, 95% CI = -0.023, -0.006, βT3 vs T1 = -0.193, 95% CI = -0.379, -0.006, Ptrend = 0.007; βcontinuous TRAP = -0.019, 95% CI = -0.041, 0.002, βT3 vs T1 = -0.291, 95% CI = -0.469, -0.112, Ptrend = 0.002). The majority of DTAC indices have no statistically significant association with semen quality parameters.

LIMITATIONS REASONS FOR CAUTION

We cannot infer causality because of the nature of the cross-sectional study design. The robustness of the conclusion may be compromised by the exactness of non-enzymatic antioxidant capacity estimation.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrated no association between DTAC indices and semen quality parameters among men attending an infertility clinic, except for ejaculate volume. Even though our findings are mostly non-significant, they contribute novel knowledge to the field of study while also laying the groundwork for future well-designed studies.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the JieBangGuaShuai Project of Liaoning Province [grant number 2021JH1/10400050], the Clinical Research Cultivation Project of Shengjing Hospital [grant number M1590], and the Outstanding Scientific Fund of Shengjing Hospital [grant number M1150]. The sponsors had no role in study design, or in the collection, analysis, and interpretation of data, or in the writing of the report, or in the decision to submit the article for publication. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Effects of cigarette smoking on semen quality, reproductive hormone levels, metabolic profile, zinc and sperm DNA fragmentation in men: results from a population-based study

Background

Cigarette smoking seems to have a negative impact on men's reproductive health, but our knowledge of its effects on the reproductive function of Russian men is still very limited. The purpose of this study was to evaluate the effect of cigarette smoking on semen quality, including sperm DNA fragmentation, hormonal, zinc and metabolic status in young men from the general multi-ethnic Russian population (n=1,222, median age 23 years) and to find out the ethno-specific effects of smoking by comparing male groups of different ethnicity.

Methods

Each participant filled out a standardized questionnaire, provided one blood and semen sample. Semen parameters, serum reproductive hormones, lipids, glucose, uric acid and seminal zinc were analyzed. Participants were classified as smokers (n=450) and non-smokers (n=772), and smokers were stratified into moderate (≤10 cigarettes/day) and heavy (>10 cigarettes/day) smokers.

Results

In the entire study population, heavy smokers were characterized by a decrease in semen volume, total sperm count, sperm concentration and motility, and an increase in sperm DNA fragmentation and teratozoospermia compared with non-smokers (p<0.05). There was also a reduction in the serum and seminal zinc level as well as an impairment in metabolic health in smokers compared with non-smokers (p<0.05). No significant differences between smokers and non-smokers were found for serum levels of LH, FSH, inhibin B, testosterone and estradiol. In the second part of our study, the most numerous ethnic groups of Slavs (n=654), Buryats (n=191), and Yakuts (n=125) were selected from the entire study population. Among three ethnic groups, the smoking intensity was higher in Slavs than in Buryats or Yakuts suggesting a greater tobacco addiction in Slavs than in Asians. A decrease in semen parameters and seminal zinc levels, and an increase in sperm DNA fragmentation and teratozoospermia was observed only in smoking Slavs (p<0.05); moderate decrease in testosterone and increase in triglyceride levels were revealed in smoking Yakuts (p<0.05), but no significant changes were detected in smoking Buryats.

Conclusion

We concluded that cigarette smoking has an ethno-specific effect on male reproductive function, probably due to the different activity of the seminal antioxidant system, which is yet to be elucidated.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

Smoking Induces a Decline in Semen Quality and the Activation of Stress Response Pathways in Sperm

Male infertility is a prevalent concern affecting couples worldwide. While genetic factors, hormonal imbalances, and reproductive system defects play significant roles, emerging evidence suggests that lifestyle choices also profoundly impact male fertility. This study aimed to explore the effects of several lifestyle factors, including tobacco and alcohol consumption, physical activity, and dietary habits, on semen quality parameters and molecular biomarkers. Thirty healthy male volunteers were recruited in the Urology service at Hospital Infante D. Pedro, Aveiro, Portugal. Participants completed lifestyle questionnaires and provided semen samples, which were analyzed according to the World Health Organization criteria by experienced technicians. We also analyzed the expression levels of antioxidant enzymes and heat-shock response-related proteins to explore the activation of signaling pathways involved in stress response within sperm cells. Our results revealed that tobacco consumption reduced semen volume and total sperm count. Although the changes in the percentage of total motility and normal morphology in the smokers' group did not reach statistical significance, a slight decrease was observed. Moreover, we identified for the first time a significant association between tobacco consumption and increased levels of heat shock protein 27 (HSP27) and phosphorylated HSP27 (p-HSP27) in sperm cells, indicating the potential detrimental effects of tobacco on the reproductive system. This study highlights that lifestyle factors reduce semen quality, possibly by inducing stress in sperm, raising awareness about the effects of these risk factors among populations at risk of male infertility.

Controversy and Consensus on the Management of Elevated Sperm DNA Fragmentation in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

PURPOSE

Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition.

MATERIALS AND METHODS

An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method.

RESULTS

A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4-6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated.

CONCLUSIONS

This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians.

Male infertility risk and gut microbiota: a Mendelian randomization study

Background

In recent decades, the decline of male sperm quality has become a worldwide phenomenon, with sperm quality of critical importance for the ability to conceive naturally. Recent studies suggest that male fertility function is closely linked to the gut microbiota, however, the cause-and-effect association between the gut microbiota and male infertility risk is currently unclear.

Methods

We performed one two-sample Mendelian randomization (MR) study, which uses summary data on human gut microbiota from the MiBioGen consortium as factors of exposure. FinnGen Consortium R8 data was used to obtain GWAS data for male infertility. To evaluate cause-and-effect associations linking gut microbiota and male infertility risk with multiple Mendelian randomization methods, we included inverse variance weighted (IVW), MR-Egger, and Maximum Likelihood (ML) Ratio. The heterogeneity of instrumental variables was evaluated through Cochran's Q, Rucker's Q, and leave-one-out analysis methods.

Results

We found a positive association between Allisonella, Anaerotruncus, Barnesiella, Intestinibacter, and Lactococcus with male infertility risk according to the MR analysis results. Bacteroides Romboutsia, Ruminococcaceae (NK4A2140group), and Ruminococcaceae (UCG011) play a protective function in male infertility pathogenesis.

Conclusion

It was found that gut microbiota and infertility are causally related in this study. In subsequent studies, there is a need to build a larger and more comprehensive GWAS database on male infertility, which will reveal the underlying mechanisms for gut microbiota and male infertility. There is a need for randomized controlled trials for validating the protective effect of the associated gut microbiota against male infertility risk, and for exploring the associated mechanisms.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Understanding the Male Perspective: Evaluating Quality of Life and Psychological Distress in Serbian Men Undergoing Infertility Treatment

The experience of an infertility diagnosis and treatment imposes a profound burden on affected individuals, encompassing not only physical and medical aspects but also a plethora of psychological, social, and emotional factors. By employing a multimodal assessment featuring validated self-report questionnaires, physical measurements, and clinical records, the present study aimed to explore the quality of life and psycho-emotional distress of men undergoing infertility treatment in Serbia, thereby addressing the dearth of research on the underrepresented male perspective in this domain. Findings revealed diverse semen abnormalities among participants (n = 96, average age 37.69 ± 5.72), with significant associations between longer treatment durations and reduced sperm motility. The observed rates of men surpassing predetermined DASS-42 questionnaire thresholds for depression, anxiety, and stress in the analyzed cohort were 13.54%, 11.46%, and 22.92%, respectively. Summary scores in conceptual areas comprised in the SF-36 questionnaire ranged from 49.00 ± 6.25 for the mental health dimension to 90.16 ± 17.75 obtained in the physical functioning subscale. Patients with a longer treatment duration demonstrated lower scores in the role emotional domain, indicative of a less favorable emotional state. Expectedly, inverse correlations were found between the SF-36 mental health score and DASS-42 subscales. By addressing the existing knowledge gap and highlighting the unique needs of infertile men, the finding of this study may contribute to a more inclusive and holistic approach to infertility research and management.

Trend of change of sperm count and concentration over the last two decades: A systematic review and meta-regression analysis

BACKGROUND

Since the 1970s, several studies found that sperm concentration (SC) and total sperm count (TSC) constantly worsened over time, mainly in high-income countries.

OBJECTIVES

To evaluate whether the decreasing trend in sperm count is continuing in Western European countries and USA, we performed a systematic review and meta-regression analysis.

MATERIALS AND METHODS

Embase and Pubmed/Medline were searched papers published in English in the 2000-2020 period limiting the search to data collected in the USA and Western European countries.

RESULTS

We identified 62 articles and pooled information on 24,196 men (range 10-2,523), collected from 1993 to 2018. Considering all the studies, random-effects meta-regression analyses showed no significant trend for SC (slope per year -0.07 mil/mL, p-value = 0.86). Negative trends of SC were detected in Scandinavian countries (slope per year -1.11 mil/mL, 95% CI: -2.40 to +0.19; p-value = 0.09), but the findings were statistically not significant. No significant trends of SC were detected in Central Europe (slope per year +0.23, 95% CI -2.51 to +2.96; p-value = 0.87), the USA (slope per year +1.08, 95% CI -0.42 to +2.57; p-value = 0.16), and Southern Europe (slope per year +0.19, 95% CI -0.99 to +1.37; p-value = 0.75). We have analyzed separately findings from studies including sperm donors, fertile men, young unselected men (unselected men, study mean age < 25 years) and unselected men (unselected men, study mean age ≥ 25 years). No significant trends of SC were observed among sperm donors (slope per year -2.80, 95% CI -6.76 to +1.17; p-value 0.16), unselected men (slope per year -0.23, 95% CI -1.58 to +1.12; p-value 0.73), young unselected men (slope per year -0.49, 95% CI -1.76 to +0.79; p-value 0.45), fertile men (slope per year +0.29, 95% CI -1.09 to +1.67; p-value 0.68).

DISCUSSION AND CONCLUSION

The results of this analysis show no significant trends in SC, in USA, and selected Western European countries.

Declined Live Birth Rate from in vitro Fertilization Fresh Cycles Performed During Chinese New Year Holiday Season

Purpose

This study aims to investigate the impact of the Chinese New Year (CNY) holiday season on the outcomes of In Vitro Fertilization (IVF) fresh embryo transfer cycles.

Participants and Methods

This retrospective study analyzed 4688 patients who received their first IVF fresh cycle attempt between January 2017 and October 2021. Of these, 4449 women underwent IVF during non-holiday seasons, while 239 women were treated during the CNY holiday season. The study included women who underwent IVF treatment during the specified time frame. The primary outcome was the live birth rate (LBR).

Results

The study found that the LBR of IVF performed during the CNY holiday season was 32.22%, which is significantly lower than that of the non-holiday season (43.38%, p<0.001). Multivariate logistic regression analysis showed that the CNY holiday season (OR=0.62, 95% CI 0.47-0.82, p=0.001) was an independent factor associated with the live birth rate. Propensity score matching (PSM) data analysis showed that the LBR in the CNY holiday season group was 31.78% compared to 42.64% in the non-holiday season group (p=0.005). Inverse probability of treatment weighting (IPTW) data also indicated that the CNY holiday season had a lower LBR than the non-holiday season (OR=0.64, 95% CI 0.47-0.87, p=0.005).

Conclusion

IVF performed during the CNY holiday season results in a lower live birth rate, potentially indicating that certain lifestyle adjustments during this period, such as unhealthy dietary, tobacco and alcohol usage, sleep disruption, and emotional stress experienced could have some influence on the outcomes.

The Impact of Heavy Smoking on Male Infertility and Its Correlation with the Expression Levels of the PTPRN2 and PGAM5 Genes

Smoking has been linked to male infertility by affecting the sperm epigenome and genome. In this study, we aimed to determine possible changes in the transcript levels of PGAM5 (the phosphoglycerate mutase family member 5), PTPRN2 (protein tyrosine phosphatase, N2-type receptor), and TYRO3 (tyrosine protein kinase receptor) in heavy smokers compared to non-smokers, and to investigate their association with the fundamental sperm parameters. In total, 118 sperm samples (63 heavy-smokers (G1) and 55 non-smokers (G2)) were included in this study. A semen analysis was performed according to the WHO guidelines. After a total RNA extraction, RT-PCR was used to quantify the transcript levels of the studied genes. In G1, a significant decrease in the standard semen parameters in comparison to the non-smokers was shown (p < 0.05). Moreover, PGAM5 and PTPRN2 were differentially expressed (p ≤ 0.03 and p ≤ 0.01, respectively) and downregulated in the spermatozoa of G1 compared to G2. In contrast, no difference was observed for TYRO3 (p ≤ 0.3). In G1, the mRNA expression level of the studied genes was correlated negatively with motility, sperm count, normal form, vitality, and sperm membrane integrity (p < 0.05). Therefore, smoking may affect gene expression and male fertility by altering the DNA methylation patterns in the genes associated with fertility and sperm quality, including PGAM5, PTPRN2, and TYRO3.

Beyond body mass index: a synthesis of lifestyle factors that may influence in vitro fertilisation outcomes

There are several lifestyle factors that are thought to potentially impact in vitro fertilisation outcomes, including body mass index, smoking, alcohol consumption, caffeine, dietary patterns and physical activity. Eligibility criteria for in vitro fertilisation in England often require individuals to be non-smokers, drug free and have a body mass index <30kg/m2. Some researchers have questioned the scientific and ethical basis for the use of body mass index thresholds in fertility treatment, citing evidence that other factors may have a greater effect on the chance of success of in vitro fertilisation. This article aims to briefly synthesise the current evidence on how other factors such as smoking, alcohol, recreational drugs, smoking, caffeine, dietary patterns and physical activity may impact in vitro fertilisation outcomes.

The Price of Human Evolution: Cancer-Testis Antigens, the Decline in Male Fertility and the Increase in Cancer

The increasing frequency of general and particularly male cancer coupled with the reduction in male fertility seen worldwide motivated us to seek a potential evolutionary link between these two phenomena, concerning the reproductive transcriptional modules observed in cancer and the expression of cancer-testis antigens (CTA). The phylostratigraphy analysis of the human genome allowed us to link the early evolutionary origin of cancer via the reproductive life cycles of the unicellulars and early multicellulars, potentially driving soma-germ transition, female meiosis, and the parthenogenesis of polyploid giant cancer cells (PGCCs), with the expansion of the CTA multi-families, very late during their evolution. CTA adaptation was aided by retrovirus domestication in the unstable genomes of mammals, for protecting male fertility in stress conditions, particularly that of humans, as compensation for the energy consumption of a large complex brain which also exploited retrotransposition. We found that the early and late evolutionary branches of human cancer are united by the immunity-proto-placental network, which evolved in the Cambrian and shares stress regulators with the finely-tuned sex determination system. We further propose that social stress and endocrine disruption caused by environmental pollution with organic materials, which alter sex determination in male foetuses and further spermatogenesis in adults, bias the development of PGCC-parthenogenetic cancer by default.

Male Infertility and the Risk of Developing Testicular Cancer: A Critical Contemporary Literature Review

Background and Objectives: The relationship between male infertility (MI) and testicular cancer (TC) is bilateral. On one hand, it is well-established that patients diagnosed with TC have a high risk of pre- and post-treatment infertility. On the other hand, the risk of developing TC in male infertile patients is not clearly defined. The objective of this review is to analyze the histopathological, etiological, and epidemiological associations between MI and the risk of developing testicular cancer. This review aims to provide further insights and offer a guide for assessing the risk factors for TC in infertile men. Materials and Methods: A comprehensive literature search was conducted to identify relevant studies discussing the relationship between MI and the risk of developing TC. Results: The incidence rates of germ cell neoplasia in situ (GCNIS) appear to be high in infertile men, particularly in those with low sperm counts. Most epidemiological studies have found a statistically significant risk of developing TC among infertile men compared to the general or fertile male populations. The concept of Testicular Dysgenesis Syndrome provides an explanatory model for the common etiology of MI, TC, cryptorchidism, and hypospadias. Clinical findings such as a history of cryptorchidism could increase the risk of developing TC in infertile men. Scrotal ultrasound evaluation for testis lesions and microlithiasis is important in infertile men. Sperm analysis parameters can be useful in assessing the risk of TC among infertile men. In the future, sperm and serum microRNAs (miRNAs) may be utilized for the non-invasive early diagnosis of TC and GCNIS in infertile men. Conclusions: MI is indeed a risk factor for developing testicular cancer, as demonstrated by various studies. All infertile men should undergo a risk assessment using clinical examination, ultrasound, and semen parameters to evaluate their risk of TC.

Controversy and Consensus on Indications for Sperm DNA Fragmentation Testing in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

PURPOSE

Sperm DNA fragmentation (SDF) testing was recently added to the sixth edition of the World Health Organization laboratory manual for the examination and processing of human semen. Many conditions and risk factors have been associated with elevated SDF; therefore, it is important to identify the population of infertile men who might benefit from this test. The purpose of this study was to investigate global practices related to indications for SDF testing, compare the relevant professional society guideline recommendations, and provide expert recommendations.

MATERIALS AND METHODS

Clinicians managing male infertility were invited to take part in a global online survey on SDF clinical practices. This was conducted following the CHERRIES checklist criteria. The responses were compared to professional society guideline recommendations related to SDF and the appropriate available evidence. Expert recommendations on indications for SDF testing were then formulated, and the Delphi method was used to reach consensus.

RESULTS

The survey was completed by 436 experts from 55 countries. Almost 75% of respondents test for SDF in all or some men with unexplained or idiopathic infertility, 39% order it routinely in the work-up of recurrent pregnancy loss (RPL), and 62.2% investigate SDF in smokers. While 47% of reproductive urologists test SDF to support the decision for varicocele repair surgery when conventional semen parameters are normal, significantly fewer general urologists (23%; p=0.008) do the same. Nearly 70% would assess SDF before assisted reproductive technologies (ART), either always or for certain conditions. Recurrent ART failure is a common indication for SDF testing. Very few society recommendations were found regarding SDF testing.

CONCLUSIONS

This article presents the largest global survey on the indications for SDF testing in infertile men, and demonstrates diverse practices. Furthermore, it highlights the paucity of professional society guideline recommendations. Expert recommendations are proposed to help guide clinicians.