The impact of different WHO reference criteria for semen analysis in clinical practice: who will benefit from the new 2021 thresholds for normal semen parameters?

One out of two idiopathic infertile men has pathologic sperm DNA fragmentation values: Potential implications for clinical practice

OBJECTIVES

To investigate the distribution of sperm DNA fragmentation (SDF) values and their association with clinical and seminal parameters in idiopathic infertile men.

DESIGN, PATIENTS, MEASUREMENTS

Data from 3224 primary infertile men (belonging to couples having failed to conceive a pregnancy within 12 months) who underwent a thorough diagnostic work-up were analysed. A SDF value ≥ 30% (according to Sperm Chromatin Structure Assay) was considered pathologic. We excluded: (1) men with genetic abnormalities; (2) men with history of cryptorchidism; (3) men with biochemical hypogonadism; (4) men with clinical varicocele; and (5) men with other possible known aetiological factors. Descriptive statistics and logistic regression analyses were used to describe the whole cohort.

RESULTS

Of all, 792 (23%) men with at least one abnormal WHO semen parameter but without any identified aetiologic factor for infertility, were considered as idiopathic infertile men. Of 792, 418 (52.7%) men had SDF ≥30%. Men with pathologic SDF were older (p = .02), had higher Follicle-stimulating hormone (FSH) (p = .04) but lower total testosterone (p = .03) values than those with SDF <30%. The homoeostatic model assessment index for insulin resistance (HOMA-IR) was higher in men with SDF ≥30% (p = .01). Idiopathic infertile men with SDF ≥30% presented with lower sperm concentration (p < .001) and lower progressive sperm motility (p < .01) than those with SDF < 30%. Logistic regression analysis revealed that older age (OR: 1.1, p = .02) and higher HOMA-IR score (OR: 1.8, p = .03) were associated with SDF ≥ 30%, after accounting for FSH and sperm concentration values.

CONCLUSIONS

Approximately half of infertile men categorized as idiopathic had pathologic SDF values. Idiopathic infertile men with pathologic SDF showed worse clinical, hormonal and semen parameters than those with normal SDF values. These results suggest that including SDF testing could be clinically relevant over the real-life management work-up of infertile men.

Contemporary Diagnostic Work-Up for Male Infertility: Emphasizing Comprehensive Baseline Assessment

Infertility is a prevalent issue affecting many couples during their reproductive years, with a significant number facing challenges in conceiving despite regular unprotected intercourse. Male factor infertility (MFI) contributes significantly to these cases, with a significant proportion of men lacking an identifiable etiology. As such, a thorough assessment of MFI has become increasingly vital for personalized management. This position paper from the Andrology team at IRCCS Ospedale San Raffaele emphasizes a comprehensive and individualized approach to MFI work-up, addressing the evolving challenges encountered in clinical practice. Our approach involves a thorough diagnostic work-up to identify the underlying causes of MFI, integrating insights from extensive literature review and our proprietary data. Our data demonstrates that an extensive diagnostic assessment allows us to identify at least one underlying cause of MFI in most infertile men. However, challenges persist in diagnosing less severe phenotypes with unclear etiology. We discuss the importance of individualized MFI work-up and its implications for developing rational therapeutic protocols. Lastly, this paper highlights the necessity for a personalized diagnostic assessment, addressing the daily clinical challenges and emphasizing tailored approaches to try to improve outcomes among couples seeking first medical help for infertility.

The Effects of Varicocelectomy on Sperm DNA Fragmentation and Conventional Semen Parameters in Men with Severe Oligoasthenoteratozoospermia: A Prospective Study

BACKGROUND

The dilation and torsion of testicular veins in the plexus pampiniformis causes Varicocele, which is a surgically repairable cause of male infertility. This study assessed the impact of varicocelectomy on semen characteristics, total motile sperm count (TMSC) and sperm DNA integrity in patients with severe oligoasthenoteratozoospermia (OAT).

MATERIALS AND METHODS

In this prospective study, semen samples of 360 men with severe OAT who underwent varicocelectomy according to World Health Organization (WHO) criteria 2021 were studied (pre-operatively and at 6, 12, and 18 months post-operatively).

RESULTS

The average age of our patients was 38.5 years. The mean spermatozoa concentration was found to be 1.60 ± 0.83 million/ml pre-operatively, while the mean post-operative concentration was 5.17 ± 1.23 million/ml at 6 months, 8.32 ± 0.98 million/ml at 12 months, and 13.51 ± 1.48 million/ml at 18 months (P<0.0001). The mean percentage of A+B motile spermatozoa was 2.92 ± 1.17% pre-operatively, 6.10 ± 1.51% at six months, 9.58 ± 1.49% at 12 months and 13.92 ± 1.88% at 18 months postoperatively (P<0.0001). The mean Modified David's morphology score was 3.80 ± 1.43% pre-operatively, 5.95 ± 1.23% at 6 months, 7.94 ± 1.18% at 12 months, and 10.82 ± 1.91% at 18 months post-operatively (P<0.0001). The mean of total motile sperm count (TMSC) was statistically improved after varicocelectomy (P<0.001). The mean of DNA fragmentation index (DFI) of the spermatozoa was 31.40 ± 0.52% pre-operatively, and post-operatively at 28.20 ± 0.32% at 6 months, 25.90 ± 0.31% at 12 months and 20.50 ± 0.40% at 18 months (P<0.001).

CONCLUSION

Varicocelectomy was associated with significant improvement of sperm parameters and DNA fragmentation resulting in significant improvement of spermatogenesis quality. We believe that universalization in the routinely used sperm dispersion chromatin (SDC) test could be beneficial in the treatment of infertility.

Low Birth Weight is Associated with Sperm DNA Fragmentation and Assisted Reproductive Technology Outcomes in Primary Infertile Men: Results of a Cross-Sectional Study

PURPOSE

To assess the relationship between clinical and semen characteristics and assisted reproductive technology (ART) outcomes with different birth weight (BW) categories in a cohort of infertile men.

MATERIALS AND METHODS

Data from 1,063 infertile men were analyzed. Patients with BW ≤2,500, 2,500-4,000, and ≥4,000 g were considered as having low BW (LBW), normal BW (NBW), and high BW (HBW), respectively. Testicular volume (TV) was assessed with a Prader orchidometer. Serum hormones were measured in all cases. Semen analyses were categorized based on 2021 World Health Organization reference criteria. Sperm DNA fragmentation (SDF) was tested in every patient and considered pathological for SDF >30%. ART outcomes were available for 282 (26.5%) patients. Descriptive statistics and logistic regression analyses detailed the association between semen parameters and clinical characteristics and the defined BW categories.

RESULTS

Of all, LBW, NBW, and HBW categories were found in 79 (7.5%), 807 (76.0%), and 177 (16.5%) men, respectively. LBW men had smaller TV, presented higher follicle-stimulating hormone (FSH) but lower total testosterone levels compared to other groups (all p<0.01). Sperm progressive motility (p=0.01) and normal morphology (p<0.01) were lower and SDF values were higher (all p<0.01) in LBW compared to other groups. ART pregnancy outcomes were lower in LBW compared to both NBW and HBW categories (26.1% vs. 34.5% vs. 34.5%, p=0.01). At multivariable logistic regression analysis, LBW was associated with SDF >30% (odd ratio [OR] 3.7; p<0.001), after accounting for age, Charlson Comorbidity Index (CCI), FSH, and TV. Similarly, LBW (OR 2.2; p<0.001), SDF >30% (OR 2.9; p<0.001) and partner's age (OR 1.3; p=0.001) were associated with negative ART outcomes, after accounting for the same predictors.

CONCLUSIONS

LBW was associated with impaired clinical and semen characteristics in infertile men compared to both NBW and HBW. SDF and ART outcomes were significantly worse in the LBW group.

Kidney function impairment in men with primary infertility: A case-control analysis

BACKGROUND

Infertile men have a worse overall health status than their fertile counterparts.

OBJECTIVE

We aimed to (1) compare kidney function in men presenting for primary couple's infertility with that of fertile men and (2) assess kidney function impairment toward sperm quality in infertile men.

MATERIALS AND METHODS

In this case-control study, 387 consecutive white-European infertile men were matched by age with 134 same-ethnicity fertile men. Complete clinical and laboratory data were available for each patient. The Chronic Kidney Disease Epidemiology Collaboration function was used for estimated glomerular filtration rate calculation. Kidney functional impairment was defined as an estimated glomerular filtration rate <90 mL/min per 1.73 m2 , according to the Kidney Disease Improving Global Outcomes criteria. Multivariable logistic regression analysis was used to (1) assess the association between kidney function impairment and infertility status and (2) investigate the association between kidney function and semen analysis abnormalities in infertile men.

RESULTS

After matching, 34 (8.8%) infertile men depicted at least a mild unknown impairment of kidney function compared to only four (3%) fertile men, with four (3%) of the infertile presenting with an overt kidney function impairment (estimated glomerular filtration rate <60 mL/min per 1.73 m2 ). There were no differences in terms of age, body mass index and rate of comorbidities between the two groups (all p > 0.05). After adjusting for major confounders, infertility status was associated with a higher risk of reduced estimated glomerular filtration rate (odds ratio 3.20; 95% confidence interval 1.21-5.2; p = 0.002). Conversely, estimated glomerular filtration rate was not associated with sperm abnormalities in infertile men.

CONCLUSIONS

Mild kidney function impairment was found in 9% of asymptomatic and unaware men presenting for primary couple's infertility investigation. This novel finding corroborates growing data on a significant association of male infertility with a poorer overall male health status and the need for tailored preventive strategies.

Next-generation sequencing analysis of semen microbiome taxonomy in men with nonobstructive azoospermia vs. fertile controls: a pilot study

OBJECTIVES

To study how the semen microbiome profile in men with nonobstructive azoospermia (NOA) differs from that of fertile controls (FCs).

DESIGN

Using quantitative polymerase chain reaction and 16S ribosomal RNA, we sequenced semen samples from men with NOA (follicle-stimulating hormone >10 IU/mL, testis volume <10 mL) and FCs and performed a comprehensive taxonomic microbiome analysis.

SETTING

All patients were identified during evaluation at the outpatient male andrology clinic at the University of Miami.

PATIENTS

In total, 33 adult men, including 14 diagnosed with NOA and 19 with proven paternity undergoing vasectomy, were enrolled.

MAIN OUTCOME MEASURES

Bacterial species in the semen microbiome were identified.

RESULTS

Alpha-diversity was similar between the groups, suggesting similar diversity within samples, whereas beta-diversity was different, suggesting differences in taxa between samples. In the NOA men, the phyla Proteobacteria and Firmicutes were underrepresented, and Actinobacteriota were overrepresented compared with FC men. At the genus level, Enterococcus was the most common amplicon sequence variant in both groups, whereas 5 genera differed significantly between the groups, including Escherichia and Shigella, Sneathia, and Raoutella.

CONCLUSION

Our study showed significant differences in the seminal microbiome between men with NOA and fertile men. These results suggest a loss of functional symbiosis may be associated with NOA. Further research into the characterization and clinical utility of the semen microbiome and its causal role in male infertility is necessary.

Paternal Age Matters: Association with Sperm Criteria's- Spermatozoa DNA Integrity and Methylation Profile

Advanced age has been reported to negatively affect sperm parameters and spermatozoa DNA integrity. A decline in sperm criteria was also associated with altered epigenetic marks such as DNA methylation with a potential downstream impact on in vitro fertilization success and clinical outcomes. The aim of the present retrospective study was to clarify the association between advanced paternal age (APA) and sperm parameters, DNA integrity and DNA methylation profile. A total of 671 patients consulting for infertility underwent sperm analysis, sperm DNA integrity assessment and methylation level measurement. The principal finding was that individuals over 40 years of age exhibit a significant increase in DNA fragmentation levels compared to the younger group (15% versus 9%, respectively, p = 0.04). However, there was no significant difference in DNA decondensation and sperm parameters in association with APA. In addition, a drop in the global methylation level was also found in men over 40 years (6% in the young group versus 2% in the old group, p = 0.03). As a conclusion, men over 40 years are at higher risk of elevated sperm DNA fragmentation and lower methylation level. Based on these observations, it is recommended that the assessment of sperm DNA fragmentation should be taken into consideration particularly after the age of 40. Our findings support the idea that paternal age is a crucial factor that should not be neglected during fertility evaluation and treatment since it is associated with epigenetics changes in sperm. Although the underlying mechanism remains to be clarified, we believe that environmental and professional exposure factors are likely involved in the process.

Efficacy of Clomiphene Citrate Versus Enclomiphene Citrate for Male Infertility Treatment: A Retrospective Study

Introduction Infertility and hypogonadism in males can greatly affect their reproductive health and overall well-being. Since exogenous testosterone administration for hypogonadism management may disrupt the normal hormonal cascade necessary for spermatogenesis, clomiphene citrate (CC) and enclomiphene citrate (EC) are medications often used to manage hypogonadism and male infertility. This study aims to directly compare the effects of CC and EC on serum testosterone levels and semen parameters in men to determine which medication may have an advantage in managing these conditions. Materials and methods We retrospectively analyzed ≥18-year-old men presenting with primary infertility, abnormal semen parameters, or hypogonadism who received CC or EC monotherapy for at least three months between January 2021 and December 2022. We compared baseline and follow-up hormone levels, semen parameters, and demographics. Variables were compared using paired and unpaired t-tests. Significance was assessed at p<0.05. Results A total of 46 men received EC and 32 men received CC. The median age was 42 (IQR: 34-47.75) years in men who received EC and 41 (IQR: 36-44) years in men who received CC (p=0.450). The two treatment groups exhibited a significant increase in serum total testosterone, while only EC had a statistically significant increase in FSH and LH. Semen volume and concentration did not significantly change with either treatment. Sperm motility increased in both groups, but total motile sperm count (TMSC) only significantly increased in men who received EC.  Conclusions Our study found that EC and CC are effective treatments in increasing total testosterone without negatively affecting spermatogenesis. EC demonstrated to be more effective in raising gonadotropin levels and TMSC.

Effect of pesticide exposure on human sperm characteristics, genome integrity, and methylation profile analysis

According to the United Nations' Food and Agriculture Organization, the quantities of pesticide used around the world have increased regularly since the 1990s. Given that pesticides may be classified as carcinogenic, mutagenic, neurotoxic, or toxic for reproduction, some have endocrine-disrupting properties that might be associated with a decline in sperm parameters in general and sperm DNA integrity in particular. These days, a sperm analysis is not enough to determine the etiology of male infertility. Genome integrity analysis is a key step in clarifying a large proportion of cases of male infertility. The objective of the present retrospective study was to assess the impact of self-reported pesticide exposure on sperm parameters and sperm DNA integrity in men consulting for infertility. In a retrospective study, a population of 671 men living in the Picardy region of France were assessed in a conventional sperm parameter analysis, Shorr staining, a DNA fragmentation assay (terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling), and chromatin decondensation with aniline blue staining. The exposed and the non-exposed groups did not differ significantly in some of the conventional sperm parameters (including volume, sperm count, and percent typical forms). However, vitality, progressive motility, and non-progressive motility were significantly lower in the exposed group. Levels of DNA fragmentation and chromatin decondensation were moderately higher in the exposed group.

Initial Andrological Evaluation of the Infertile Male

Evaluation of a man presenting for couple infertility starts with obtaining a thorough medical history, and the couple's reproductive and sexual history. Semen analysis, according to World Health Organization recommendations, is the cornerstone of male partner evaluation. A comprehensive physical examination is essential for every male partner, with adequate assessment of the development of secondary sexual characteristics. However, more complex testing than semen analysis (eg, sperm DNA fragmentation index) may be required in selected cases. For men with oligozoospermia or azoospermia, a hormonal evaluation should be performed, including at least total testosterone, follicle stimulating hormone, and luteinising hormone. Genetic testing should be offered to azoospermic men and those with severe oligozoospermia. Ultrasound of the genitourinary tract can provide additional information in select cases. PATIENT SUMMARY: A complete medical history, physical examination, and semen analysis are essential components of the initial evaluation of men being assessed for infertility. The evaluation must proceed in parallel for male and female partners to optimise management for infertile couples.

The Effect of Varicocele Treatment on Fertility in Adults: A Systematic Review and Meta-analysis of Published Prospective Trials

CONTEXT

The benefits and harms of varicocele treatment versus observation in adult infertile males are still controversial.

OBJECTIVE

To systematically pool the evidence on outcomes of varicocele treatment (any surgical or radiological) versus observation in adult infertile men.

EVIDENCE ACQUISITION

A systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Only prospective randomized and nonrandomized studies were included until November 2021. The primary outcome was pregnancy rate; the secondary outcomes were improvements in sperm concentration, normal morphology, and progressive sperm motility after treatment compared to baseline. Men ≥18 yr of age with any-grade varicoceles were included.

EVIDENCE SYNTHESIS

Of 557 articles identified, 12 were eligible for inclusion, involving 1357 patients. Varicoceles were treated surgically in ten and radiologically in four studies. Varicocele treatment improved pregnancy rates (odds ratio 1.29; 95% confidence interval [CI] 1.00-1.65; p = 0.048) and sperm concentration (mean difference 12.34 million/ml, 95% CI 3.49-21.18; p = 0.006) compared with observation. Proportions of spermatozoa with normal morphology and progressive motility were not statistically different from those with observation. However, considering treatment arm only, sperm concentration, progressive motility, and normal sperm morphology were improved compared with baseline. A subgroup analysis showed that the benefit of varicocele treatment is evident in men with an abnormal semen analysis. The main limitation is represented by the heterogeneity of the included studies, mostly in terms of study population, fertility of the partner, outcome evaluation, lack of long-term outcomes, and intermediate/high risk of bias.

CONCLUSIONS

Treatment of any-grade varicoceles may improve pregnancy rates and sperm concentration in adult infertile men, while benefits in sperm motility and normal morphology are less clear.

PATIENT SUMMARY

In this systematic review and meta-analysis of all published prospective trials on varicocele treatment, significant evidence emerged on its benefit in terms of improved pregnancy rates and sperm concentration, while benefits in sperm motility and morphology are less clear.

Pilot Study: Next-generation Sequencing of the Semen Microbiome in Vasectomized Versus Nonvasectomized Men

BACKGROUND

Approximately half a million vasectomies are performed every year in the USA. There is a paucity of literature on the impact of male sterilization on the semen microbiome and whether it prompts microbiota dysbiosis.

OBJECTIVE

To investigate if vasectomy induces changes in the seminal microbiome via comparison of semen samples from men before and after vasectomy, and if the seminal microbiome profiles for vasectomized men follow a particular pattern with respect to diversity and abundance.

DESIGN, SETTING, AND PARTICIPANTS

From July 2021 to February 2022, we prospectively collected and analyzed semen samples from 58 men at one outpatient clinic. Eighteen men provided a semen sample before and 3 mo after vasectomy. We also collected semen samples from 22 fertile nonvasectomized men and from a further 18 vasectomized men at 3 mo after vasectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Semen microbiome α-diversity, beta-diversity, and relative abundance were compared initially between paired and then between unpaired vasectomized and nonvasectomized samples. Analysis of variance (ANOVA), permutational multivariate ANOVA, and analysis of the composition of microbiomes with bias correction were used to assess differences.

RESULTS AND LIMITATIONS

In both paired and unpaired sets of samples, a decreasing trend for α-diversity in semen after vasectomy was observed. Shannon diversity, the relative abundance of species with an abundance >2%, and composition were not significantly changed. Sphingomonas, Brevundimonas, and Paracoccus abundance decreased after vasectomy, while Corynebacterium abundance increased. The results may be limited by the sample size and lack of demographic heterogeneity.

CONCLUSIONS

Vasectomy is followed by a decrease in α-diversity and changes in the relative abundance of bacterial species in the semen microbiome. Further investigation is necessary to understand the clinical significance of these changes after vasectomy.

PATIENT SUMMARY

We evaluated changes in the bacteria species in semen after vasectomy. We found that vasectomy decreased the richness and evenness of bacteria species in semen, but the overall bacterial community remained similar. Further studies are needed to assess the implications of changes in semen bacteria after vasectomy.

Clinically Meaningful Improvements in Sperm DNA Fragmentation Severity in Infertile Men Treated with Superoxide Dismutase Supplementation: A Single-Center Experience

Background. Antioxidants are commonly used for the treatment of idiopathic male infertility. Previous studies have shown that antioxidants are able to improve sperm quality, but little is known about their impact on sperm DNA fragmentation (SDF). Preliminary findings showed that superoxide-dismutase (SOD)-based antioxidant plus hydroxytyrosol and carnosol (FertiPlus® SOD) therapy was associated with SDF improvement in a small cohort of infertile men. Therefore, we aimed to assess rates of and predictors of semen parameters and SDF improvements in infertile men treated with FertiPlus® SOD therapy (SOD+) or with other antioxidants without SOD (SOD−) in the real-life setting. Methods. Data from 60 consecutive infertile men with baseline SDF ≥ 30% and treated with SOD+ or SOD− for at least three months were analyzed. Clinical parameters and serum hormones were collected. Sperm parameters and SDF were requested at baseline and after SOD+ or SOD− treatment. Clinically meaningful SDF change after treatment was defined as SDF improvement >20% compared to baseline. Propensity score matching was performed to adjust for baseline differences between groups. Descriptive statistics were used to compare clinical and hormonal characteristics between SOD+ and SOD− groups. Semen characteristics were compared before and after treatment. Logistic regression models investigated the association between clinical variables and SDF improvement. Results. Groups were similar in terms of clinical, serum hormones and semen parameters at baseline after matching. Compared to baseline, sperm progressive motility (17 (10−36)% vs. 27 (12−41)%) and normal morphology (2 (1−6)% vs. 4 (2−6)%) significantly improved after SOD+ treatment (all p < 0.01), but not after SOD−. SDF values significantly improved after treatment in both groups, compared to the baseline evaluation (all p < 0.01). However, SDF values were lower after SOD+ than SOD− treatment (30 (22−36)% vs. 37 (31−42)%, p = 0.01). Similarly, a clinically meaningful improvement in SDF at follow-up was more frequently found after SOD+ than SOD− treatment (76.7% vs. 20.0%, p = 0.001). Multivariable logistic regression analysis showed that SOD+ treatment (OR 5.4, p < 0.001) was an independent predictor of clinically meaningful SDF improvement, after accounting for age and baseline FSH values. Conclusions. This cross-sectional study showed that, in a cohort of primary infertile men with SDF ≥ 30%, SOD-based treatment was significantly effective in improving SDF compared to antioxidants without SOD. Approximately 80% of men treated with SOD+ achieved clinically meaningful improvement in SDF after three months of treatment. Sperm progressive motility and normal morphology also improved after SOD+ therapy but not after SOD−. These results suggest that SOD+ treatment could be considered an effective option for the management of idiopathic infertile men with elevated SDF.