The impact of ejaculatory abstinence on semen analysis parameters: a systematic review

Does shorter ejaculatory abstinence improve intra uterine insemination outcomes in couples with unexplained infertility? A cohort study

OBJECTIVE

To assess the impact of duration of ejaculatory abstinence on live birth rates in Intrauterine Insemination (IUI) cycles.

STUDY DESIGN

Retrospective cohort study at a university-level tertiary care centre from January 2019 to June 2023. A total of 573 cycles in 463 couples with unexplained infertility were included in the study. We had three cohorts based on the duration of ejaculatory abstinence: Group I - ≤ 2 days, Group II - 3-7 days, and Group III - > 7 days. The primary outcome assessed was the live birth rate per IUI cycle. Secondary outcomes included pregnancy rate per cycle, clinical pregnancy rate per cycle, and miscarriage rate per clinical pregnancy.

RESULTS

The live birth rate per cycle was 9.6 % in Group 1, 9.3 % in Group 2, and 18.8 % in Group 3, and there was no statistically significant difference among the three cohorts (p = 0.230). The clinical pregnancy rate per IUI cycle was 11.7 %, 12.0 % & 18.8 % in groups 1, 2 & 3, respectively, which was comparable among the groups (p = 0.474). Logistic regression analysis done after adjusting for potential confounders showed no significant association of ejaculatory abstinence with live birth {adjusted odds ratio (aOR) for group1: 0.93 (95 % CI 0.50 - 1.73, p = 0.827), for group 3: 2.58 (95 % CI 0.90 - 7.36 p = 0.076)} with group 2 as the reference.

CONCLUSION

For couples with unexplained infertility undergoing IUI, a shorter ejaculatory abstinence period of ≤ 2 days does not significantly enhance the live birth rates compared to standard or prolonged abstinence.

Correlation analysis of age, abstinence, and seasons with semen parameters in untreated male partners of infertile couples

Many studies reveal the presence of an effect of age, abstinence and seasons on semen parameters, but the number of patients enrolled is small and the presence of therapies unknown. We aimed to evaluate the correlation between abstinence days, age, season, and semen parameters (volume, concentration, progressive motility, total number of sperms, morphology) among men referred to our laboratory. We proceeded with a cross-sectional, observational, exploratory study in an Andrology laboratory. A population of 348 male partners of infertile couples who did not receive any treatment in the 3 months preceding semen analysis was selected. Sperm volume, concentration, total number, progressive motility and morphology of sperms were conducted strictly following the guidelines indicated in the last edition of WHO manual for semen analysis. Pearson's correlation analysis and Kendall's correlation analysis were applied. Sperm concentration, semen volume and sperm total number moderately increased as well as the abstinence, while progressive motility and morphology moderately decreased. Regarding the age, in the 20-35 age group there was a weak inverse association with concentration, total number, motility and morphology and a weak positive association with volume; in the 42-63 age group there was a moderate positive association between age and concentration, motility and morphology, but an inverse association with volume. No correlation emerged between seasonal variations and semen parameters. These results suggested the importance of correct information to patients for proper semen analysis for diagnostic and therapeutic purposes.

Ejaculatory abstinence and its impacts on within- and between-individual variations in semen parameters of 9,595 Vietnamese men

Background

Ejaculatory abstinence (EA) is the key to assessing the semen analysis. While its fundamental roles on all sperm and semen parameters have been studied for decades, there are still controversies about whether shortening or lengthening EA would be beneficial. Despite natural variations of human semen, most studies in this field investigate the influence of EA using between-individual approaches that cannot control intra-individual covariates. There is still little evidence on how deviation in EA between two samplings affects variations in semen parameters. This study aimed to revisit the relationship between EA and semen parameters, especially in the within-individual analysis and in terms of two-time EA deviations.

Methods

A cross-sectional study was conducted on 11,297 conventional semen examinations from 9,595 men who presented for reproductive health check-ups between May 2017 and December 2022, aiming to assess between-individual variation. Among them, 1,702 men doing semen analysis twice within 1 month were selected to investigate the role of two-time EA deviation further.

Results

EA positively correlated with the semen volume, sperm concentration, and total motile sperm count (TMSC), consistent in both between- and within-individual analyses. However, according to the linear regression model, there were no clear peaks in the above parameters following EA elongation. Sperm concentration and TMSC from the two samplings differed when the two-time EA deviation was no more than 1 day. On the other hand, the proportion of total motility tends to increase with lengthening the EA (β=0.16, P<0.01) in between-individual but not in within-individual analysis. Moreover, this study showed no correlation between the straight-line velocity (VSL) and EA. Variations in semen parameters would be reduced when the EA deviation between two samplings was decreased.

Conclusions

This study reaffirms the importance of EA in sperm quantity. EA should be maintained consistently or deviate by no more than 1 day to minimize variations between the two samples.

The effect of consecutive ejaculation on the sperm parameters in the oligo-astheno-teratozoospermia (OAT) men

Recently, the World Health Organization recommendation for abstinence time for semen analysis has been challenged in some studies and many of them have supported the advantages of a second short abstinence ejaculation. More evidence is needed to approve this for clinical use. This study aimed to compare the average routine abstinence time (2-7 days) with the short time (1-2 h) on sperm quality based on functional parameters in a population of oligo-astheno-teratozoospermia (OAT) men. The semen samples were retrieved from 50 men with OAT two times: one standard 2-7 days (long ejaculation) and short duration trimming (1-2 hours later the first ejaculation). All semen parameters as well as sperm DNA integrity were compared between groups. Results showed that mean sperm concentration (10.40 vs. 8.76), total sperm count (28.53 vs. 12.24) and mean semen volume (2.69 vs. 1.40) were higher in the first ejaculation (2-7 days of abstinence), while progressive motility (20.52 vs. 13.32), non-progressive motility (53.46 vs. 48.86), morphology (2.46 vs. 1.46) and viability (83.90 vs. 77.96) were significantly higher in the second ejaculation (P < 0.05). The second sample also showed lower immotile (26.82 vs. 38.02) and DNA fragmentation (19.5 vs. 26.96) (P < 0.05). Taking all data into account, an additional short abstinence period (AP) may be a simple and helpful strategy to obtain better sperm quality in couples with male infertility causes, especially in OAT patients. The recommended current guidelines regarding the AP may need to be revisited in severe male factors.

Association of abstinence time with semen quality in men who undergoing fertility evaluation: a cross-sectional study from 3052 participants

Objective

Abstinence time has been associated with semen quality, but the results remain controversial.

Methods

This study recruited 3052 men undergoing fertility evaluation. Abstinence time (AT) was categorized as short (0-1 day), WHO-recommended (2-7 days) and long (>7 days). Semen parameters including volume, sperm concentration, progressive motility, total motility, total motility sperm count (TMSC), morphology and DNA fragmentation index were assessed for their association with AT.

Results

Short AT was significantly associated with lower semen volume (P< 0.001), sperm concentration (P= 0.01) and TMSC (P< 0.001), while long AT was significantly associated with higher sperm concentration (P= 0.006), reduced progressive motility (P= 0.005) and total motility (P= 0.02), and higher DFI (P< 0.001). Restricted cubic spline models demonstrated a non-linear relationship between AT and the risk of low semen volume (Pnon-linear < 0.001), sperm concentration (Pnon-linear = 0.039) and TMSC (Pnon-linear < 0.001).

Conclusions

Our findings suggest both short and long AT were significantly associated with lower sperm quality, which indicated the importance of maintaining a recommended AT (2-7days) for semen analysis. Additionally, short abstinence periods may be recommended to maintain optimal sperm DNA integrity.

Sperm DNA Fragmentation and Fertility

Elevated levels of sperm deoxyribonucleic acid (DNA) fragmentation (SDF) have been associated with several adverse reproductive outcomes, including: lower natural and assisted reproductive technology (ART) pregnancy rates, abnormal embryo development, and recurrent pregnancy loss. However, due to conflicting study results, limited high-level evidence, multiple clinically available assays, and variable standard reference ranges, precisely how SDF testing should be applied to the evaluation and treatment of infertile men remains controversial. To better understand SDF and its role in clinical practice, this chapter aims to: (1) review the literature that has made SDF such a controversial topic, (2) discuss newly published evidence contributing to this complex discussion, and (3) outline the most recent practice guidelines currently available.

Enhancing Sperm Quality Through Consecutive Ejaculation After Short Abstinence in Men with Low Semen Parameters Undergoing ICSI

Background

Longer abstinence time is believed to be associated with the production of reactive oxygen species (ROS), which in excessive amounts may be detrimental to the sperm. To enhance sperm quality, multiple research studies have proposed reducing the duration of abstinence by encouraging consecutive ejaculations. This approach has been shown to improve sperm motility and morphology, which are associated with better ICSI and IUI outcomes. The purpose of the current study was to evaluate sperm quality and fertilization rate, cleavage rate, as well as embryo quality in severe oligoasthenozoospermic men using the consecutive ejaculate collected within an hour of abstinence.

Methods

A prospective study was conducted at Halim Fertility Center from August 2020-April 2022, involving male partners undergoing ICSI treatment who presented with severe oligoasthenozoospermia on their previous semen analysis. The non-parametric Mann-Whitney and Wilcoxon tests were used to analyze the parameters of the groups, including characteristics of the study participants, oocytes and sperm samples, as well as the ICSI outcomes, using a significance level of 5%.

Results

A statistically significant improvement in the sperm total motility was recorded in the consecutive ejaculate compared to the first (31.53±11.73% vs. 22.52±8.85%; p<0.001). Both fertilization and cleavage rates were higher in the consecutive ejaculate group, although they were not statistically significant (61.41±28.04% vs. 55.45±31.76%; p=0.081 and 88.10±28.63% vs. 81.07±36.34%; p=0.262).

Conclusion

Consecutive ejaculates collected within an hour of the first may enhance sperm total motility, fertility, and cleavage rates in male partners with low sperm count and quality undergoing ICSI treatment.

Impact of Shorter Abstinence Periods on Semen Parameters: A Systematic Review and Meta-Analysis

PURPOSE

The success of assisted reproductive technology (ART) relies heavily on semen parameters, and it is influenced by the length of the abstinence period. The World Health Organization (WHO) recommends a 2- to 7-day abstinence period. Even so, efficacy is still suboptimal. Thus, this study aims to determine whether shorter abstinence periods (<2 days) can improve semen parameters.

MATERIALS AND METHODS

This study is a systematic review and meta-analysis. A literature search was performed across five databases: PubMed, Embase, ProQuest, Scopus, and Wiley Online Library using the PICO format. Retrieved articles were assessed according to eligibility criteria and the PRISMA flow diagram. Those eligible for quantitative analysis were assessed using forest plots. Risks of bias were tested using the Newcastle-Ottawa Scale.

RESULTS

A total of 22 studies and 31,640 samples were included. Studies showed that short abstinence periods significantly reduced semen volume (mean difference [MD] -0.83, p<0.01), sperm concentration (MD -8.39, p<0.01), and DNA fragmentation (MD -3.82, p<0.01). No differences in sperm morphology were identified. Meanwhile, the overall effect for total (MD 2.30, p<0.05) and progressive motile sperm (MD 2.18, p<0.01) was significantly increased. Subgroup analysis on oligospermia patients revealed a significant increase in normal sperm morphology (MD 1.64, p<0.01) along with reduced DNA fragmentation (MD -3.30, p<0.05). However, no significant changes were seen among other sperm parameters.

CONCLUSIONS

In conclusion, our findings suggest a shorter abstinence period could be beneficial due to its effect on sperm motility and DNA fragmentation. Additionally, oligospermia patients will benefit from improved sperm morphology. These findings can provide insight for future guidelines to promote a shorter abstinence period for improving ART outcomes.

Optimized sperm selection: a highly efficient device for the isolation of progressive motile sperm with low DNA fragmentation index

PURPOSE

To identify the sperm preparation procedure that selects the best sperm population for medically assisted reproduction.

METHODS

Prospective observational study comparing the effect of four different sperm selection procedures on various semen parameters. Unused raw semen after routine diagnostic analysis was split in four fractions and processed by four different methods: (1) density gradient centrifugation (DGC), (2) sperm wash (SW), (3) DGC followed by magnetic activated cell sorting (MACS), and (4) using a sperm separation device (SSD). Each fraction was analyzed for progressive motility, morphology, acrosome index (AI), and DNA fragmentation index (DFI).

RESULTS

With DGC as standard of care in intraclass correlation coefficient analysis, only SSD was in strong disagreement regarding progressive motility and DFI [0.26, 95%CI (- 0.2, 0.58), and 0.17, 95%CI (- 0.19, 0.45), respectively]. When controlling for abstinence duration, DFI was significantly lower after both MACS and SSD compared to DGC [- 0.27%, 95%CI (- 0.47, - 0.06), p = 0.01, and - 0.6%, 95%CI (- 0.80, - 0.41), p < 0.001, respectively]. Further comparisons between SSD and MACS indicate significantly less apoptotic cells [Median (IQR) 4 (5), 95%CI (4.1, - 6.8) vs Median (IQR) 5 (8), 95%CI (4.9, - 9.2), p < 0.001, respectively] and dead cells [Median (IQR) 9.5 (23.3), 95%CI (13.2, - 22.4) vs Median (IQR) 22 (28), 95%CI (23.1, - 36.8), p < 0.001, respectively] in the SSD group.

CONCLUSION

The selection of a population of highly motile spermatozoa with less damaged DNA from unprocessed semen is ideally performed with SSD. Question remains whether this method improves the embryological outcomes in the IVF laboratory.

Abstinence for sperm sample collection and ART outcome: an unsubstantiated myth

PURPOSE OF REVIEW

Semen analysis is a basic component of male evaluation. Reproductive centers typically instruct men to provide a semen specimen based on recommendations from WHO Standard for semen examination. Evidence that these recommendations optimize sperm reproductive capacity is lacking. Existing data to optimize sperm quality with shorter abstinence were reviewed.

RECENT FINDINGS

Several recent studies have reviewed the effects of shorter ejaculatory abstinence of semen quality and assisted reproductive technology (ART) outcomes. Shorter abstinence was defined as 1 h-1 day in one review, and <4 h in the other systematic meta-analysis and review.

SUMMARY

Prior instructions for male patients have not been designed to optimize fertility potential for semen analyses. Optimal sperm quality is obtained by instructing men to have a short abstinence (certainly <1 day, and preferably <4 h) for semen specimens used for in vitro fertilization (assisted reproduction).

Effects of long and short ejaculatory abstinence on sperm parameters: a meta-analysis of randomized-controlled trials

Purpose

This study aimed to investigate the effects of ejaculatory abstinence on sperm parameters.

Methods

This analysis was registered in PROSPERO (CRD42023472124). We performed a search on PubMed using the following text terms: (("sperm parameters" OR "sperm analysis" [Mesh]) AND ("sperm DNA fragmentation" OR "DNA fragmentation" [Mesh]) AND ("sexual abstinence" [Mesh] OR "abstinence")) and an advanced search in Scopus using the terms ("sperm parameters" OR "sperm parameters" OR "DNA fragmentation") AND ("abstinence"). The sperm parameters that were investigated were sperm volume, total sperm motility, progressive sperm motility, sperm concentration, sperm morphology, and sperm DNA fragmentation (SDF). A two-day cut-off as a "short" or "long" abstinence period has been defined.

Results

Thirteen studies published between 2013 and 2022 were included in this meta-analysis. A total of 2,315 patients, ranging from 6 to 836 from each cohort, were enrolled in the study. We showed that longer abstinence time was associated with greater sperm concentration (mean difference [MD]: 8.19; p <0.01), sperm volume (MD: 0.96; p <0.01), and higher SDF (MD: 3.46; p <0.01), but lower progressive sperm motility (MD: -1.83; p <0.01). Otherwise, no statistically significant difference was observed in patients with longer vs. shorter abstinence times regarding total sperm motility (MD: -1.83; p = 0.06). Meta-regression analysis showed that days of abstinence were positively and linearly related to sperm concentration (slope: 3.74; p <0.01) and SDF (slope: 0.65; p = 0.044).

Conclusions

According to our data, short ejaculatory abstinence is associated with better sperm quality. Indeed, a higher percentage of progressive sperm motility and lower levels of SDF have been reported in a short abstinence cohort. In contrast, the long abstinence group reported a higher sperm concentration.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023472124.

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.

Oxidative Stress and Acrosomal Status of Human Spermatozoa Subjected to Hydrophobic Carbon Soot Treatments

The fourth industrial revolution extensively reshapes the reality we are living in by blurring the boundaries of physical, digital and biological worlds. A good example is the previously unthinkable incursion of nanoscale waste materials, such as soot, into the technologies for assisted reproduction. Although the rapeseed oil soot may efficiently enhance the progressive motility of human spermatozoa, it is yet unknown whether this material induces undesirable oxidative stress and premature acrosome reaction, endangering the sperm-oocyte fusion and blastocyst formation. In an attempt to clarify this issue, we reveal that the three-hour incubation of human semen mixed with three main types of soot does not cause oxidative stress and spontaneous acrosome reaction of the sperm. These unique findings are attributed to synchronous elimination and stabilization of the oxidants via hydrogen bonding to the acidic groups of the soot (i.e., C=O and/or C-O-C) and electron donation by its basic chemical sites (i.e., C-OH and/or COOH). Moreover, the soot nanoparticles are electrostatically attracted by discrete positively charged areas on the sperm head, increasing its negative charge and in some cases interfering the acrosome reaction. Such novel mechanistic insights emphasize the credibility of rapeseed oil soot to confidently shift from the purely diagnostic and therapeutic phases in reproductive medicine to research dealing with the effect of carbon nanomaterials on the embryo development and implantation.

Effect of ejaculatory abstinence period on fertilization and clinical outcomes in ICSI cycles: a retrospective analysis

RESEARCH QUESTION

Does ejaculatory abstinence impact fertilization outcomes in intracytoplasmic sperm injection (ICSI) cycles in infertile couples?

DESIGN

This single-centre retrospective observational study included 6919 ICSI cycles from 2013 to 2022. The primary outcome was the assessment of oocyte fertilization, measured in terms of the rate of formation of two-pronuclear (2PN), 3PN and 1PN zygotes. Secondary outcomes were blastulation, cumulative positive β-human chorionic gonadotrophin test and clinical pregnancy rates. Relationships between ejaculatory abstinence and fertilization outcomes, and ejaculatory abstinence and clinical outcomes were evaluated with multivariable analysis, including possible confounders.

RESULTS

A positive association was observed between ejaculatory abstinence and semen sample volume (P < 0.001), sperm concentration (P < 0.001) and total motile sperm count (P < 0.001). No association was found between the 1PN zygote rate and ejaculatory abstinence (P = 0.97). Conversely, for each additional day of ejaculatory abstinence, the likelihood of obtaining 2PN zygotes from all inseminated oocytes decreased by 3% [adjusted odds ratio (aOR) 0.97, 95% CI 0.94-0.99], whilst the likelihood of obtaining 3PN zygotes from all inseminated oocytes increased significantly by 14% (aOR 1.14, 95% CI 1.07-1.22). No significant associations were found between ejaculatory abstinence and blastulation, cumulative pregnancy or miscarriage rates.

CONCLUSIONS

A longer ejaculatory abstinence period significantly decreases the rate of 2PN zygotes, and increases the rate of 3PN zygotes without directly affect blastulation and pregnancy rates.

Gonadotropin axis and semen quality in young Swiss men after cannabis consumption: Effect of chronicity and modulation by cannabidiol

BACKGROUND

While cannabis is the most widely used recreational drug in the world, the effects of phytocannabinoids on semen parameters and reproductive hormones remain controversial. Cannabinoid receptors are activated by these compounds at each level of the hypothalamus-pituitary-gonadotropic axis.

OBJECTIVES

To assess the impact of the consumption of Δ-9-tetrahydrocannabinol and cannabidiol on semen parameters, as well as on male reproductive hormone and endocannabinoid levels, in a cohort of young Swiss men.

MATERIALS AND METHODS

The individuals in a Swiss cohort were divided according to their cannabis consumption. In the cannabis user group, we determined the delay between the last intake of cannabis and sample collection, the chronicity of use and the presence of cannabidiol in the consumed product. Urinary Δ-9-tetrahydrocannabinol metabolites were quantified via gas chromatography-mass spectrometry. Blood phytocannabinoids, endocannabinoids and male steroids were determined via liquid chromatography-mass spectrometry/mass spectrometry, and other hypothalamus-pituitary-gonadotropic axis hormones were determined via immunoassays. Semen parameters such as sperm concentration and motility were recorded using computer-assisted sperm analysis.

RESULTS

Anandamide, N-palmitoyl ethanolamide, androgens, estradiol and sex hormone binding globulin levels were all higher in cannabis users, particularly in chronic, recent and cannabidiol-positive consumers. Gonadotropin levels were not significantly different in these user subpopulations, whereas prolactin and albumin concentrations were lower. In addition, cannabis users had a more basic semen pH and a higher percentage of spermatozoa with progressive motility. However, the two latter observations seem to be related to a shorter period of sexual abstinence in this group rather than to the use of cannabis.

CONCLUSIONS

Because both cannabidiol and Δ-9-tetrahydrocannabinol are frequently used by men of reproductive age, it is highly relevant to elucidate the potential effects they may have on human reproductive health. This study demonstrates that the mode of cannabis consumption must be considered when evaluating the effect of cannabis on semen quality.

Collecting semen samples at home for fertility assessment: time for a new standard?

BACKGROUND

In fertility clinics the standard approach to semen collection involves a private room close to the laboratory to avoid fluctuations in temperature and to control the time between collection and processing. There are still no firm conclusions whether collecting semen at home has any influence on sperm quality and reproductive competence. The purpose of this study was to assess whether the site of semen collection affects semen parameters.

METHODS

This retrospective cohort study performed at a tertiary level public fertility center included 8634 semen samples from 5880 men undergoing fertility assessment from 2015 to 2021. The impact of sample collection site was evaluated using a generalized linear mixed model. A subgroup analysis comparing clinic to home collection within the same patient was performed on 1260 samples from 428 men by paired t-test or Wilcoxon Signed Rank Test.

RESULTS

Samples collected at home (N.=3240) had significantly higher semen volume, sperm concentration and total sperm count respect to samples collected at clinic (N.=5530) (median (range): 2.9 (0.0-13.9) mL versus 2.9 (0.0-11.5) mL, P=0.016; 24.0 (0.0-252.0) million/mL versus 18.0 (0.0-390.0), P<0.0001; 64.6 (0.0-946.0) million versus 49.3 (0.0-1045.0), P<0.0001, respectively). There was no difference in abstinence period and sperm motility. Paired comparisons of semen characteristics in 428 patients with home-collected (N.=583) and clinic-collected (N.=677) samples confirmed a no negative effect on volume and total sperm count.

CONCLUSIONS

Our data provide evidence for a not disadvantage with collection at home.

Global trends in semen quality of young men: a systematic review and regression analysis

PURPOSE

Many studies have reported declines in semen quality mainly focused on total sperm counts (TSC) and sperm concentration (SC), ignoring the importance of progressive motile sperm (PR), total motile sperm (TM), and normal morphological sperm (NM). Therefore, we performed a comprehensive meta-analysis to explore the trend in semen quality of young men.

METHODS

We searched 3 English databases and 4 Chinese databases from January 1980 to August 2022. Random-effect meta-analyses and weighted linear regression models were conducted to perform the trend in semen quality.

RESULTS

Finally, 162 eligible studies including 264,665 men from 28 countries were got between 1978 and 2021. Significant decreases were observed in TSC (- 3.06 million/year, 95% CI - 3.28 to - 2.84), SC (- 0.47 million/ml/year, 95% CI - 0.51 to - 0.43), and PR (- 0.15%/year, 95% CI - 0.20 to - 0.09), and there was an upward trend in TM (0.28%/year, 95% CI 0.24 to 0.32). The results of meta-regression analyses indicated that age, continent, income, WHO criteria, and abstinence time significantly impacted on TSC, SC, PR, and TM. Positive regression coefficients were observed in some categories suggesting that outcomes might not be declining and even increasing in these subgroups.

CONCLUSIONS

Downward trends in semen quality among global young men were observed in our study, including TSC, SC, and PR. But TM did not appear to be trending down or even to be leveling off. More studies are needed to focus on the causes of the declines.

The Influence of Male Ejaculatory Abstinence Time on Pregnancy Rate, Live Birth Rate and DNA Fragmentation: A Systematic Review

Variation in ejaculatory abstinence time and its influence on semen quality and clinical reproductive outcomes is a growing concern among clinicians and researchers. The WHO (World Health Organization) recommends 2–7 days of abstinence time prior to semen collection for diagnostic purposes; however, the evidence that such an abstinence period leads to better pregnancy outcomes remains unclear. The aim of this systematic review is to evaluate short and long ejaculatory abstinence time in association with pregnancy rate, live birth rate and DNA fragmentation, in order to make a recommendation on an ideal timeframe for ejaculatory abstinence. This review is conducted according to the PRISMA guidelines and registered in PROSPERO (CRD42022379039). The electronic databases PubMed, Embase and Cochrane were searched for eligible studies. The Scottish Intercollegiate Guidelines Network was used for the assessment of the risk of bias across the included studies. Twenty-four studies were included in this systematic review. The included studies confirm that a shorter abstinence time is associated with improved pregnancy rates and live birth rates following assisted reproductive technology compared with longer ejaculatory abstinence times at different cut-off points. Similarly, a lower DNA fragmentation index was reported in semen analyses collected from short abstinence times compared with long abstinence times. However, due to the heterogeneity of the included studies, it is not possible to extract an ideal time of ejaculatory abstinence, but all outcomes improved with shorter ejaculatory abstinence times. This systematic review confirms that short ejaculatory abstinence times, less than those recommended by the WHO for diagnostic purposes, are associated with higher pregnancy and live birth rates and improved DNA fragmentation, when compared to long ejaculatory abstinence times.

Ejaculation: the Process and Characteristics From Start to Finish

Purpose of Review

Semen analysis serves as the initial step in the evaluation of male infertility. However, given the difficulty in interpreting abnormal findings, physicians and patients often struggle with understanding the results. In this review, we aim to review the normal physiology of ejaculation and create an accessible resource for interpreting abnormal semen volume, viscosity, liquefaction, pH, appearance, and color.

Recent Findings

Emerging evidence has revealed that men with genitourinary tract infections have a greater number of seminal leukocytes, which may result in clumping of motile sperm and altered morphology. Hence, these patients may have abnormal sperm parameters secondary to their health status. Recent findings have further characterized the semen liquefaction process, suggesting that increased levels of semenogelin and decreased levels of proteases and plasminogen activators (e.g., urokinase and chymotrypsin) may be associated with the failure of semen to convert to a watery consistency.

Summary

This article creates a resource which may be referenced when abnormalities in semen analysis are encountered. We offer a comprehensive overview of normal ejaculation physiology and abnormal variants in male ejaculate volume-including aspermia, anejaculation, retrograde ejaculation, and hypo- and hyperspermia-and their potential etiologies. Additionally, we discuss several processes (infection, inflammation, and dysfunction of male sex glands) which may affect semen viscosity, liquefaction, and pH. Finally, our discussion of the potential colors of male ejaculate is meant to reduce the anxiety of both patient and provider. Through a better understanding of the process and varying characteristics of ejaculation, physicians may adequately counsel their patients on abnormal findings and concerns regarding infertility.

Lifestyle-, environmental-, and additional health factors associated with an increased sperm DNA fragmentation: a systematic review and meta-analysis

INTRODUCTION

Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an evidence-based test for fertility evaluations depicting fertility more clearly than standard semen parameters. Therefore, we aimed to summarize the potential prognostic factors of a higher SDF.

METHODS

We conducted a systematic search in three medical databases and included studies investigating any risk factors for SDF values. We calculated mean differences (MD) in SDF with 95% confidence interval (CI) for exposed and non-exposed individuals.

RESULTS

We included 190 studies in our analysis. In the group of associated health conditions, varicocele (MD = 13.62%, CI: 9.39-17.84) and impaired glucose tolerance (MD = 13.75%, CI: 6.99-20.51) had the most significant increase in SDF. Among malignancies, testicular tumors had the highest impact, with a maximum of MD = 11.3% (CI: 7.84-14.76). Among infections, the overall effects of both Chlamydia and HPV were negligible. Of lifestyle factors, smoking had the most disruptive effect on SDF - an increase of 9.19% (CI: 4.33-14.06). Different periods of sexual abstinence did not show significant variations in SDF values. Age seemed to have a more drastic effect on SDF from age 50 onwards, with a mean difference of 12.58% (CI: 7.31-17.86). Pollution also had a detrimental effect - 9.68% (CI: 6.85-12.52).

CONCLUSION

Of the above risk factors, varicocele, impaired glucose tolerance, testicular tumors, smoking, pollution, and paternal age of over 50 were associated with the highest SDF.

TRIAL REGISTRATION

CRD42021282533.

Sperm DNA Damage and Its Relevance in Fertility Treatment: A Review of Recent Literature and Current Practice Guidelines

Sperm deoxyribonucleic acid (DNA) damage has recently emerged as one of the most controversial topics in male reproductive medicine. While level I evidence indicates that abnormal sperm DNA damage has substantial adverse effects on reproductive outcomes (including chance of pregnancy and risk of miscarriage), there is limited consensus on how sperm DNA fragmentation (SDF) testing should be performed and/or interpreted in clinical practice. In this article, we review: (1) how SDF is assessed, (2) cumulative evidence regarding its impact on reproductive outcomes, (3) methods for mitigating high SDF, and (4) the most recent practice guidelines available for clinicians regarding the use and interpretation of SDF testing.

Optimizing outcomes for men with severe infertility

PURPOSE OF REVIEW

To evaluate recent evidence related to optimizing outcomes for men with severe infertility, including effect of ejaculatory abstinence interval on semen parameters and assisted reproductive technology (ART) outcomes, and impact of cryopreservation on surgically retrieved testicular sperm obtained from men with nonobstructive azoospermia (also referred to as azoospermia due to spermatogenic dysfunction).

RECENT FINDINGS

Recent evidence strongly suggests that a short abstinence interval improves sperm motility and ART outcomes. Similarly, recent studies have concluded that using fresh vs. frozen testicular sperm results in higher live birth rates.

SUMMARY

Although the World Health Organization currently recommends a 2- to 7-day ejaculatory abstinence period, this interval is based more on the need to standardize semen parameters than clinical outcomes. In fact, recent evidence suggests that shorter abstinence consistently improves sperm motility and ART outcomes for infertile men. Similarly, recent studies have reported an improvement in live birth rates with fresh (vs. frozen) testicular sperm, though their retrospective design and lack of intention to treat analyses makes it difficult to draw strong conclusions. Although additional, well designed studies are needed, providers may be able to leverage these techniques in their practice to improve outcomes for some infertile men.

Decline of Sperm Quality over the Last Two Decades in the South of Europe: A Retrospective Study in Infertile Patients

Semen quality has a direct relation to male fertility. Whether sperm variables in humans have decreased over the last years is still uncertain, with some studies showing a decline and others reporting no changes. In this regard, previous research has suggested that lifestyle and environmental conditions may contribute to this variability, calling for regional studies. The present work is a retrospective, unicentric study that includes semen samples analyzed between 1997 and 2017 at the Parc Taulí Hospital (Barcelona metropolitan area). First, a multivariate analysis including the age as a confounding factor showed a statistically significant decrease in semen volume, pH, progressive motility, morphology and total motile sperm over time. Contrarily, no significant variation in sperm count or concentration was observed. Mean reductions per year were -0.02 mL for volume, -0.57% for progressively motile sperm and -0.72% for sperm with normal morphology. Interestingly, the average annual temperature registered by the Spanish Meteorology Agency negatively correlated to sperm morphology and sperm count (Rs = -0.642; p = 0.002 and Rs = -0.435; p = 0.049, respectively). In conclusion, the present study based on infertile patients from the Barcelona area found a decline in sperm motility and morphology, without effects on sperm count. Changes in temperature appeared to be associated to this decline, but further studies are needed to address the mechanisms linked to the observed variations.

Lifestyle, Insulin Resistance and Semen Quality as Co-Dependent Factors of Male Infertility

Infertility is a problem that affects millions of couples around the world. It is known as a disease of couples, not individuals, which makes diagnosis difficult and treatment unclear. Male infertility can have many causes, from mechanical ones to abnormal spermatogenesis or spermiogenesis. Semen quality is determined by a number of factors, including those dependent on men themselves, with the number of infertile men growing every year. These include, e.g., diet, physical activity, sleep quality, stress, among many others. As these factors co-exist with insulin resistance, which is a disease closely related to lifestyle, it has been singled out in the study due to its role in affecting semen quality. In order to examine connections between lifestyle, insulin resistance, and semen quality, a review of literature published from 1989 to 2020 in the following databases PubMed/Medline, EMBASE (Elsevier), Scopus, Web of Science, and Google Scholar was performed. Hence, semen quality, environment, and insulin resistance are interrelated, thus it is difficult to indicate which aspect is the cause and which is the effect in a particular relationship and the nature of possible correlations. Since the influence of lifestyle on semen quality has been extensively studied, it is recommended that more thorough research be done on the relationship between insulin resistance and semen quality, comparing the semen quality of men with and without insulin resistance.

The Impact of a Very Short Abstinence Period on Conventional Sperm Parameters and Sperm DNA Fragmentation: A Systematic Review and Meta-Analysis

PURPOSE

In recent years, a growing number of studies have supported the beneficial effects of a very short abstinence period on sperm parameters, especially in patients with oligoasthenozoospermia. However, the results are controversial and no consensus exists regarding whether to request a second semen collection in clinical practice. Therefore, this systematic review and meta-analysis aimed to evaluate the influence of a very short abstinence period (within 4 h) on conventional sperm parameters and sperm DNA fragmentation (SDF) rate.

MATERIALS AND METHODS

The literature search was performed using Scopus and PubMed databases. The meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) guidelines. All eligible studies were selected according to the Population, Intervention, Comparison/Comparator, Outcomes, and Study design (PICOS) model. The quality of evidence of the included studies was analyzed through the Cambridge Quality Checklists. The standardized mean difference (SMD) was used to analyze the outcomes. Cochran-Q and I² statistics were used to evaluate statistical heterogeneity.

RESULTS

We assessed for eligibility 1334 abstracts, and 19 studies were finally included. All 19 articles evaluated the effects of a very short abstinence period on sperm parameters and, among these, 5 articles also evaluated the effects on SDF rate. The quantitative analysis showed a significant reduction in semen volume after a very short abstinence period in both normozoospermic men and patients with oligozoospermia, asthenozoospermia, and/or teratozoospermia (OAT) patients. We found a statistically significant increase in sperm concentration and total and progressive motility in the second ejaculation of patients with OAT. In contrast, the SDF rate decreased significantly in the second ejaculate of OAT patients.

CONCLUSIONS

This is the first systematic review and meta-analysis investigating the impact of a very short abstinence period on sperm parameters and SDF rate. The results suggest that collecting a second consecutive ejaculation after a very short time from the first could represent a simple and useful strategy for obtaining better-quality spermatozoa, especially in patients with abnormal sperm parameters.

Effects of virtual reality erotica on ejaculate quality of sperm donors: a balanced and randomized controlled cross-over within-subjects trial

BACKGROUND

Previous research has shown that the type and duration of erotic material that men have access to during masturbation can influence semen parameters. To our knowledge, the use of virtual reality (VR) headsets to present erotica has not previously been studied. We reasoned that, because VR can provide a more immersive experience to the user, semen parameters of masturbatory ejaculates may be altered.

METHODS

This study had a balanced and randomized controlled cross-over within-subjects design. 504 ejaculates were collected from 63 sperm donors at 4 locations in Denmark. During masturbation each donor was instructed to observe erotic material either on a touch screen monitor or using a VR headset. The order of each pair of within-subject treatments was randomized by the throw of a dice. Anonymized data were analysed with linear mixed and piecewise structural equation models.

RESULTS

Both abstinence period and VR-use influenced the total number of motile spermatozoa ejaculated. For short abstinence periods, VR-use increased the number of motile sperm in the ejaculate. However, the difference between VR and non-VR ejaculates decreased as abstinence period increased such that there was no difference at the mean abstinence period of 58 h. For longer abstinence periods, total motile sperm counts were lower, on average, when men used VR compared to those that did not.

CONCLUSION

The use of VR headsets to view erotica had a strong positive effect on the number of motile sperm in an ejaculate when the donor's abstinence time was short (< 24 h). VR-use could improve the ejaculate quality of men who are asked to provide samples after a short period of abstinence, such as men in infertile partnerships producing samples for ART or cancer patients depositing sperm before treatment.

TRIAL REGISTRATION

Trial retrospectively registered on 13 July 2022 at ClinicalTrials.gov. Identifier: NCT05457764.

The impact of male factors and their correct and early diagnosis in the infertile couple's pathway: 2021 perspectives

PURPOSE

The current clinical practice in reproductive medicine should pose the couple at the centre of the diagnostic-therapeutic management of infertility and requires intense collaboration between the andrologist, the gynaecologist and the embryologist. The andrologist, in particular, to adequately support the infertile couple, must undertake important biological, psychological, economical and ethical task. Thus, this paper aims to provide a comprehensive overview of the multifaceted role of the andrologist in the study of male factor infertility.

METHODS

A comprehensive Medline, Embase and Cochrane search was performed including publications between 1969 and 2021.

RESULTS

Available evidence indicates that a careful medical history and physical examination, followed by semen analysis, always represent the basic starting points of the diagnostic work up in male partner of an infertile couple. Regarding treatment, gonadotropins are an effective treatment in case of hypogonadotropic hypogonadism and FSH may be used in men with idiopathic infertility, while evidence supporting other hormonal and nonhormonal treatments is either limited or conflicting. In the future, pharmacogenomics of FSHR and FSHB as well as innovative compounds may be considered to develop new therapeutic strategies in the management of infertility.

CONCLUSION

To provide a high-level of care, the andrologist must face several critical diagnostical and therapeutical steps. Even though ART may be the final and decisive stage of this decisional network, neglecting to treat the male partner may ultimately increase the risks of negative outcome, as well as costs and psychological burden for the couple itself.

Preliminary prediction of semen quality based on modifiable lifestyle factors by using the XGBoost algorithm

Introduction

Semen quality has decreased gradually in recent years, and lifestyle changes are among the primary causes for this issue. Thus far, the specific lifestyle factors affecting semen quality remain to be elucidated.

Materials and methods

In this study, data on the following factors were collected from 5,109 men examined at our reproductive medicine center: 10 lifestyle factors that potentially affect semen quality (smoking status, alcohol consumption, staying up late, sleeplessness, consumption of pungent food, intensity of sports activity, sedentary lifestyle, working in hot conditions, sauna use in the last 3 months, and exposure to radioactivity); general factors including age, abstinence period, and season of semen examination; and comprehensive semen parameters [semen volume, sperm concentration, progressive and total sperm motility, sperm morphology, and DNA fragmentation index (DFI)]. Then, machine learning with the XGBoost algorithm was applied to establish a primary prediction model by using the collected data. Furthermore, the accuracy of the model was verified via multiple logistic regression following k-fold cross-validation analyses.

Results

The results indicated that for semen volume, sperm concentration, progressive and total sperm motility, and DFI, the area under the curve (AUC) values ranged from 0.648 to 0.697, while the AUC for sperm morphology was only 0.506. Among the 13 factors, smoking status was the major factor affecting semen volume, sperm concentration, and progressive and total sperm motility. Age was the most important factor affecting DFI. Logistic combined with cross-validation analysis revealed similar results. Furthermore, it showed that heavy smoking (>20 cigarettes/day) had an overall negative effect on semen volume and sperm concentration and progressive and total sperm motility (OR = 4.69, 6.97, 11.16, and 10.35, respectively), while age of >35 years was associated with increased DFI (OR = 5.47).

Conclusion

The preliminary lifestyle-based model developed for semen quality prediction by using the XGBoost algorithm showed potential for clinical application and further optimization with larger training datasets.

Influence of ejaculatory abstinence period on semen quality of 5165 normozoospermic and oligozoospermic Nigerian men: A retrospective study

BACKGROUND AND AIMS

Several studies have shown that the length of ejaculatory abstinence alters sperm quality. However, the available data are conflicting and none seems to exist in a Nigerian population. The present study aims to compare the semen quality in normozoospermic and oligozoospermic semen samples of a homogenous Nigerian population, following varying ejaculatory abstinence days (EAD); less than 2, 2-3, and 3-7 days.

METHODS

The present retrospective study included 5165 semen samples collected over 5 years, from April 2015 to April 2020.

RESULTS

In normozoospermic samples, sperm count and total sperm count were significantly higher in prolonged EAD. In oligozoospermic patients, semen volume significantly increased with prolonged EAD, while sperm count, total sperm count, and progressive motility were significantly reduced with prolonged EAD. In addition, EAD and sperm volume positively correlated in oligozoospermic patients.

CONCLUSION

Our findings indicate that EAD affects sperm quality in both normozoospermic and oligozoospermic men with varying impacts. Prolonged EAD increased sperm count and total sperm count in normozoospermic patients, while EAD increased semen volume but reduced sperm count, total sperm count, and progressive motility in oligozoospermic patients.

Metabolomics of Human Semen: A Review of Different Analytical Methods to Unravel Biomarkers for Male Fertility Disorders

Background: Human life without sperm is not possible. Therefore, it is alarming that the fertilizing ability of human spermatozoa is continuously decreasing. The reasons for that are widely unknown, but there is hope that metabolomics-based investigations may be able to contribute to overcoming this problem. This review summarizes the attempts made so far. Methods: We will discuss liquid chromatography–mass spectrometry (LC-MS), gas chromatography (GC), infrared (IR) and Raman as well as nuclear magnetic resonance (NMR) spectroscopy. Almost all available studies apply one of these methods. Results: Depending on the methodology used, different compounds can be detected, which is (in combination with sophisticated methods of bioinformatics) helpful to estimate the state of the sperm. Often, but not in all cases, there is a correlation with clinical parameters such as the sperm mobility. Conclusions: LC-MS detects the highest number of metabolites and can be considered as the method of choice. Unfortunately, the reproducibility of some studies is poor, and, thus, further improvements of the study designs are needed to overcome this problem. Additionally, a stronger focus on the biochemical consequences of the altered metabolite concentrations is also required.

Sperm characteristics in normal and abnormal ejaculates are differently influenced by length of ejaculatory abstinence

BACKGROUND

No association between the length of ejaculatory abstinence (LEA) and semen characteristics has been confirmed. A short LEA has been linked to improved sperm characteristics and a higher pregnancy rate, but its negative influence on sperm chromatin maturity and longevity may adversely affect reproductive outcomes.

OBJECTIVES

We sought to determine the influence of LEA on: (i) semen parameters in normozoospermic and abnormal ejaculates; and (ii) the outcomes of sperm-preparation methods in a large number of sub-fertile men undergoing infertility workups.

MATERIALS AND METHODS

This retrospective registry-based cohort study analyzed the data of 10,674 ejaculates from 7,972 sub-fertile men, who were then segregated into normozoospermic, oligozoospermic, asthenozoospermic, and oligo-asthenozoospermic cohorts. Variations in semen characteristics and post-wash outcomes were studied between 4 LEA intervals across 0-15 days.

RESULTS

An age-adjusted analysis of covariance (ANCOVA) model linked significant increases in ejaculate volume, sperm concentration (except in the oligozoospermic cohort), and total sperm number to an increased LEA (p < 0.05). LEA was negatively associated with motility (except in the asthenozoospermic cohort) and vitality (p < 0.05). Large-headed spermatozoa were less common with an increased LEA only in the oligoasthenozoopermic cohort (p < 0.05). In the normozoospermic cohort, a longer LEA led to fewer sperm with amorphous heads but more sperm with tapered heads and cytoplasmic droplets (p < 0.05). LEA extension resulted in greater sperm DNA fragmentation in the abnormal cohort (p < 0.01). The post-wash sperm concentration and total motile sperm count were significantly improved with a longer LEA in the normozoopsermic cohort (p < 0.05).

DISCUSSION AND CONCLUSION

Considering the findings in this study and existing literature, a generalized recommendation for long LEA has no clinical value. The LEA should be individualized based on the ejaculate profile and the need for specific clinical intervention. This article is protected by copyright. All rights reserved.

Associations between Meat and Vegetable Intake, Cooking Methods, and Asthenozoospermia: A Hospital-Based Case–Control Study in China

Background: The role of meat and vegetable intake in the development of asthenozoospermia has been controversial, and the role of cooking methods for meat and vegetables in the association has yet to be determined. The present study aimed to illuminate the relationship between the consumption and cooking methods of meat and vegetables and the risk of asthenozoospermia. Methods: In this hospital-based case–control study, we enrolled 552 patients with asthenozoospermia and 585 healthy controls. Dietary information was assessed using a validated self-administered food frequency questionnaire. Asthenozoospermia was diagnosed according to the fifth edition of the WHO laboratory manual for the examination and processing of human semen. Results: Participants in the highest tertile of total meat and unprocessed meat intake had a 44% and 39% lower risk of asthenozoospermia than those in the lowest tertile (OR = 0.56, 95% CI: 0.37, 0.87 and OR = 0.61, 95% CI: 0.40, 0.93), respectively. Participants with the highest processed meat consumption showed higher risk (OR = 1.44, 95% CI: 1.01, 2.06). Raw vegetable consumption was negatively associated with the risk of asthenozoospermia (OR = 0.67, 95% CI: 0.45, 0.98). The stir-frying cooking method for meat was associated with increased risk of asthenozoospermia (OR = 1.58, 95% CI: 1.02, 2.46). Conclusions: Intake of total meat, unprocessed meat, and raw vegetable may reduce asthenozoospermia risk, while higher consumption of processed meat may increase the risk. Cooking methods may play a role in these associations. These findings need to be confirmed in large and prospective cohort studies.

Management of male factor infertility: position statement from the Italian Society of Andrology and Sexual Medicine (SIAMS) : Endorsing Organization: Italian Society of Embryology, Reproduction, and Research (SIERR)

PURPOSE

Infertility affects 15-20% of couples and male factors are present in about half of the cases. For many aspects related to the diagnostic and therapeutic approach of male factor infertility, there is no general consensus, and the clinical approach is not uniform.

METHODS

In the present document by the Italian Society of Andrology and Sexual Medicine (SIAMS), endorsed by the Italian Society of Embryology, Reproduction, and Research (SIERR), we propose evidence-based recommendations for the diagnosis, treatment, and management of male factor infertility to improve patient and couple care.

RESULTS

Components of the initial evaluation should include at minimum medical history, physical examination, and semen analysis. Semen microbiological examination, endocrine assessment, and imaging are suggested in most men and recommended when specific risk factors for infertility exist or first-step analyses showed abnormalities. Full examination including genetic tests, testicular cytology/histology, or additional tests on sperm is clinically oriented and based on the results of previous investigations. For treatment purposes, the identification of the specific cause and the pathogenetic mechanism is advisable. At least, distinguishing pre-testicular, testicular, and post-testicular forms is essential. Treatment should be couple-oriented, including lifestyle modifications, etiologic therapies, empirical treatments, and ART on the basis of best evidence and with a gradual approach.

CONCLUSION

These Guidelines are based on two principal aspects: they are couple-oriented and place high value in assessing, preventing, and treating risk factors for infertility. These Guidelines also highlighted that male infertility and in particular testicular function might be a mirror of general health of a man.

Sperm Vitality and Necrozoospermia: Diagnosis, Management, and Results of a Global Survey of Clinical Practice

Sperm vitality testing is a basic semen examination that has been described in the World Health Organization (WHO) Laboratory Manual for the Examination and Processing of Human Semen from its primary edition, 40 years ago. Several methods can be used to test sperm vitality, such as the eosin-nigrosin (E-N) stain or the hypoosmotic swelling (HOS) test. In the 6th (2021) edition of the WHO Laboratory Manual, sperm vitality assessment is mainly recommended if the total motility is less than 40%. Hence, a motile spermatozoon is considered alive, however, in certain conditions an immotile spermatozoon can also be alive. Therefore, the differentiation between asthenozoospermia (pathological decrease in sperm motility) and necrozoospermia (pathological decrease in sperm vitality) is important in directing further investigation and management of infertile patients. The causes leading to necrozoospermia are diverse and can either be local or general, testicular or extra-testicular. The andrological management of necrozoospermia depends on its etiology. However, there is no standardized treatment available presently and practice varies among clinicians. In this study, we report the results of a global survey to understand current practices regarding the physician order of sperm vitality tests as well as the management practices for necrozoospermia. Laboratory and clinical scenarios are presented to guide the reader in the management of necrozoospermia with the overall objective of establishing a benchmark ranging from the diagnosis of necrozoospermia by sperm vitality testing to its clinical management.

Assessment of hormonal status in male infertility. An update

BACKGROUND AND AIMS

The prevalence and incidence of infertility are increasing worldwide; they are associated with a significant economic and social impact. Infertility is defined as the inability to achieve pregnancy after 12 months or more of regular unprotected sex. In recent times, the male factor has gained importance and currently it contributes to approximately 50% of infertility cases. Multiple etiologies are stated, such as metabolic, anatomical, genetic or even idiopathic causes; however, the main cause is semen abnormalities. The aim of this manuscript is to provide a complete review of hormonal assessment of male infertility, as well as to review the physiology and pathophysiology related to the male gonadal axis.

METHODS

This study is a narrative abstract carried out on basis of systematic bibliographic review, using articles indexed in PubMed/Medline, Scopus, Embase and Scielo, which were published during the last 20 years.

RESULTS

The cornerstone of the evaluation of the hormonal status is semen analysis. Clinicians must rule out hypogonadism in those patients who present oligospermia and azoospermia, by determining levels of testosterone and gonadotropins, which provide the functionality status of the hypothalamic-pituitary-testicular axis. Evaluation of the adrenal, thyroid, and lactotroph axis are indicated in those patients with central hypogonadism.

CONCLUSIONS

Despite advances in the diagnosis of male infertility, some causes are not fully understood, therefore, it is crucial to perform a timely hormonal evaluation of the male factor in infertile couples, in order to provide adequate treatment and improve fertility rates.

Does a Very Short Length of Abstinence Improve Assisted Reproductive Technique Outcomes in Infertile Patients with Severe Oligo-Asthenozoospermia?

In recent years, a growing number of studies seem to support the beneficial effects of a very short abstinence period on sperm parameters, especially in patients with oligo-asthenozoospermia (OA). On this basis, the aim of this study was to evaluate the effects of a short period of abstinence (1 h) on intracytoplasmic sperm injection (ICSI) outcomes in infertile patients with severe OA. We performed a retrospective study on 313 ICSI cycles in which couples were divided into two different groups based on sperm parameters of the male partners. Group 1 included normozoospermic men or male partners with a mild OA (n = 223). Group 2 included male partners with severe OA (n = 90). They were asked to provide a second consecutive ejaculation after 1 h from the first one. The best ejaculate was used to perform ICSI. We found a significant increase of total (p < 0.001) and progressive motility (p < 0.001) in the second ejaculate of patients of Group 2 compared with those of the first one. Spermatozoa of the second ejaculate were chosen for ICSI for all patients in Group 2. We found statistically significant improvement of clinical pregnancy rate (p = 0.001) and embryo quality (p = 0.003) in couples in Group 2 compared to those of Group 1. No statistically significant difference was found in fertilization, implantation, live birth delivery, and miscarriage rates between the two groups. Therefore, a second semen sample collected after a very short time-interval in patients with severe OA allowed us to obtain significantly higher clinical pregnancy rate with improved embryo quality compared to normozoospermic men or patients with mild OA. Fertilization, implantation, live birth delivery, and miscarriage rates were similar between the two groups. The present study shows that a second consecutive ejaculate could represent a simple strategy to obtain better sperm parameters and assisted reproductive technology (ART) outcomes in infertile patients with mild-severe OA.

Is Ejaculation Frequency in Men Related to General and Mental Health? Looking Back and Looking Forward

Despite its relevance for human sexuality, literature on potential effects of ejaculation frequency and masturbation on general and mental health outcomes is sparse. Reasons for this knowledge gap include a general lack of interest, but also methodological challenges and still existing superstition. This paper reconciles literature from various fields to extract relevant information on how ejaculation frequency effects general and mental health outcomes. Culture-bound syndromes have been reported in countries still strictly tabooing or condemning masturbation. Masturbatory guilt describes a phenomenon in individuals experiencing a discrepancy between moral standards and own behavior with respect to masturbation. Abstinence is one aspect under study in the area of fertility treatment. Specific time frames and their respective implications on quality of sperm remain inconclusive. Limited temporal resolution capacities hamper the precise study of brain structures directly activated during ejaculation. The relation between ejaculation frequency and hormonal influences remains poorly understood. Future research that specifically addresses ejaculation frequency and potential mental and general health outcomes is needed. In contrast to extracting knowledge as a byproduct from other studies with a different focus, this enables sound study designs and could provide evidence-based results which could then be further discussed and interpreted.

The Effect of Male Sexual Abstinence Periods on the Clinical Outcomes of Fresh Embryo Transfer Cycles Following Assisted Reproductive Technology: A Meta-Analysis

A sexual abstinence period (SAP) lasting for 2–7 days is recommended before undertaking semen analyses. However, there is no consensus regarding the length of the SAP for couples using assisted reproductive technology (ART). Therefore, a meta-analysis was performed to compare the effect of short SAPs (less than 4 days) and long SAPs (4–7 days) on the clinical outcomes of fresh embryo transfer cycles after ART. A total of four studies were included in the meta-analysis. Although the fertilization rate in short SAP couples was higher than that in long SAP couples, a pooled analysis demonstrated that it was not statistically significant (p = .09). The implantation rate was, however, significantly higher in short SAP couples (p = .0001). The pooled analysis revealed that the pregnancy rate was significantly higher in short SAP couples than that in long SAP couples. The overall odds ratio (OR) for the pregnancy rate was 1.44 (p = .0006). No significant difference in miscarriage rates between the short and long SAP couples was found (p = .88). The meta-analysis indicates that a shorter abstinence period could result in higher implantation and pregnancy rates for patients undertaking ART treatments.

Evaluation of testicular spermatogenic function by ultrasound elastography in patients with varicocele-associated infertility

OBJECTIVE

To investigate the application of ultrasound elastography and color Doppler ultrasound in the evaluation of testicular spermatogenic function in patients with varicocele (VC) associated infertility.

METHODS

A total of 196 patients with VC-associated infertility treated in our hospital from January 2018 to January 2020 were included as the research subjects (VC group), and were classified into VC I group (66 cases), VC II group (60 cases), and VC III group (70 cases) according to the diameter of spermatic vein and the degree of reflux under ultrasound. 50 age-matched healthy subjects were included as the control group. Color ultrasound, ultrasound elastography and semen examination were performed on all patients.

RESULTS

Compared with control group, a lower left testicular volume in VC group and a lower right testicular volume in VC III group were observed, and the left testicular volume was inversely proportional to VC grade (all P<0.05). Statistically significant differences in sperm viability, sperm density, peak systolic velocity (PSV), and MEAN values were determined among the 4 groups by one-way ANOVA, and between two groups by the independent-samples t test (all P<0.05). Pearson correlation analysis revealed that sperm viability and sperm density had no correlation with PSV, resistive index (RI) and pulsatility index (PI) of the left testicular artery in VC group, but were negatively correlated with the MEAN values of the testis.

CONCLUSION

Ultrasound elastography can predict the semen quality in patients with VC-associated infertility.

CLINICAL TRIAL REGISTRATION

This study was registered with the registration No. ChiCTR2010189 (URL: http://www.chictr.org.cn/showproj.aspx?proj=2018XE057-3).

The Effect of Ejaculatory Abstinence Interval on Sperm Parameters and Clinical Outcome of ART. A Systematic Review of the Literature

Since the publication of the first edition of the WHO (World Health Organization) Laboratory Manual for the examination of Human Semen in 1980, the reference values of sperm parameters have been updated on four occasions. Currently and globally, most of the laboratories analyzing semen samples use the latest, 5th edition of the manual that recommends ejaculatory abstinence from two to seven days before producing the sample for examination. While this standardized interval of time facilitates the interpretation of the results and research, no solid evidence exists to support the WHO-recommended abstinence time for a semen analysis in order to optimize clinical outcomes after assisted reproduction. Most of the studies refer to different clinical outcomes, different groups of patients and different editions of the WHO Laboratory Manual, including heterogeneous intervals of abstinence or sperm parameters. The aim of the current systematic review was to evaluate available evidence correlating ejaculatory abstinence time with clinical outcomes and sperm parameters analyzed according to the last edition of the World Health Organization Laboratory Manual reference values in different male populations. The results from the included studies indicate that WHO abstinence recommendations may need revision, given that a shorter ejaculatory abstinence interval appears to be associated with improved sperm parameters, such as sperm DNA fragmentation, progressive motility or morphology, while evidence suggests a potential increase in embryo euploidy rates and pregnancy outcomes.

Temporal trends in semen concentration and count among 327 373 Chinese healthy men from 1981 to 2019: a systematic review

STUDY QUESTION

Are there temporal trends of sperm concentration (SC) and total sperm count (TSC) in Chinese healthy males from 1981 to 2019?

SUMMARY ANSWER

Our result indicated a temporal decrease in SC and TSC among 327 373 healthy Chinese men in the recent four decades.

WHAT IS KNOWN ALREADY

A review of 61 papers reported a temporal decline in SC and TSC from 1938 to 1990. This trend was later confirmed by a systematic review of 185 published papers from 1981 to 2013. However, the majority of the included individuals were from western countries. In China, whether SC and TSC have declined remains controversial.

STUDY DESIGN, SIZE, DURATION

This systematic review of published articles used data extracted from Pubmed, Science Direct, Embase, China-National-Knowledge-Infrastructure (CNKI) and Wanfang Data to assess changes in SC and TSC in China from 1981 to 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 111 studies including 327 373 individuals who provided semen samples from 1981 to 2019 were extracted for the present analysis. Study selection and data extraction were performed by two independent researchers. The trends in SC and TSC were analysed using liner-regression and meta-regression before and after adjusting for potential covariates. Moreover, subgroups, categorised based on geographic region, fertility status or recruitment source, were also analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

SC declined significantly (slope liner-regression = -0.748 million/ml/year; P = 0.005; slope meta-regression = -0.824 million/ml/year; P < 0.001) between 1981 and 2019 in China. Trends for TSC was similar to that for SC (slope liner-regression = -2.073 million/year; P = 0.032; slope meta-regression = -2.188 million/year; P = 0.003). In subgroup meta-regression analyses, males with definite fertility had continuous declines in SC (slope northern group=-2.268, P = 0.009; slope southern group=-1.014, P = 0.009) and TSC (slope northern group=-9.675, P = 0.010; slope southern group=-3.215, P = 0.042). However, in the unselected group, where fertility status was unknown, the obvious downward trend in SC was only seen in males from Northern regions (slope = -0.836, P = 0.003). Another subgroup analysis demonstrated that obvious decreases in SC (slope = -1.432, P < 0.001) and TSC (slope=-4.315, P = 0.001) were only seen in volunteer groups but not in pre-pregnancy examination groups and other recruitment groups. The results changed minimally in multiple sensitivity analyses.

LIMITATIONS, REASONS FOR CAUTION

The validity of the meta-analysis results was limited mainly by the quality of the included studies. Additionally, our study spanned many decades and the recommended criteria for some semen parameter assessments have significantly changed, which may bring about some unavoidable bias. Moreover, the data remain insufficient especially in some provinces of China.

WIDER IMPLICATIONS OF THE FINDINGS

The present study is the first study to report significant decreases in SC and TSC in 327 373 healthy Chinese men between 1981 and 2019, indicating a serious reproductive health warning. Further studies on the causes of the declines are urgently needed.

STUDY FUNDING/COMPETING INTEREST(S)

D.Z. is supported by the National Natural Science Funding of China, Natural Science Funding of Shaanxi Province, Science Funding of Health Department, Shaanxi Province, Fundamental Research Funds for the Central University and the Project of Independent Innovative Experiment for Postgraduates in Medicine in Xi'an Jiaotong University. The authors have no conflicts of interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Short Ejaculatory Abstinence in Normozoospermic Men is Associated with Higher Clinical Pregnancy Rates in Sub-fertile Couples Undergoing Intra-Cytoplasmic Sperm Injection in Assisted Reproductive Technology: A Retrospective Analysis of 1691 Cycles

BACKGROUND

The current WHO abstinence recommendations are ideal only for clinical diagnosis, as in recent years a negative correlation of abstinence duration with good embryo development and clinical pregnancy rate has been seen.

AIM

The aim of the study was to evaluate the impact of variation in abstinence period on fertilization, embryo development potential, pregnancy, and miscarriage rate in sub-fertile couples undergoing assisted reproductive technology (ART) treatment.

SETTING AND DESIGN

A prospective analysis was conducted at a tertiary (level 3) infertility care clinic.

MATERIALS AND METHODS

The study included analysis of 1691 cycles for the patient undergoing ART procedures between September 2017 and August 2019. The influence of ejaculatory abstinence (EA) was investigated based on variation in abstinence length with four groups: Group I - 1 day; Group II - 2-5 days; Group III - 6-7 days; and Group IV - EA length of ≥8 days.

STATISTICAL ANALYSIS

Analysis of variance and Chi-square test were used to calculate P value.

RESULTS

In our primary outcome, we have seen a strong positive correlation of abstinence duration with semen volume, total sperm count, total motile count, and difference between each group was significant. Secondary outcomes showed a significantly higher implantation rate, biochemical pregnancy rate was observed in Group I (1 day) per embryo transfer as compared to longer abstinence groups. This resulted in significantly higher clinical pregnancy rates in Group I 30.0% vs. 25.4% in comparison to longer abstinence groups.

CONCLUSIONS

Our study has shown duration of abstinence is negatively correlated with positive β-human chorionic gonadotropin rate, clinical pregnancy rate, and implantation rate. Lower miscarriage rate was also observed with shorter abstinence duration.

Two subsequent seminal productions: A good strategy to treat very severe oligoasthenoteratozoospermic infertile couples

BACKGROUND

Sexual abstinence is considered one of the several factors that influence sperm quality. Recent studies show that a shortening of the abstinence period could be beneficial mostly in oligoasthenoteratozoospermic (OAT) patients.

OBJECTIVE

Retrospective study to verify the efficacy of a second semen sample after a short abstinence to treat severe OAT infertile patients.

MATERIALS AND METHODS

127 couples treated between May 2014 and May 2018 were divided into two groups. Study Group 1 (75 cycles): severe OAT characteristics: count <0.2 × 10⁶ /mL no progressive motility; count ≥0.2 × 10⁶ /mL and no total or progressive motility; 0% normal morphology; a second semen sample was requested after abstinence of 2 h. Control Group 0 (52 cycles): normozoospermic or mild OAT; only one sample was requested. Intracytoplasmic sperm injection was utilized in all cases.

RESULTS

All semen parameters were significantly different between Group 0 vs both samples of Group 1 (p < 0.001), excluding volume between Group 0 and 1st sample of Group 1 (p = 0.682). The comparison between 1st and 2nd samples from Group 1 showed significant differences in volume, total and progressive motility and morphology (p < 0.001, p < 0.001, p < 0.020) but not in total sperm count (p = 0.970). Fertilization, pregnancy rate/transfer, implantation and miscarriage rates were 85.9% and 61.1% (p < 0.001), 30.6% and 35.8% (p = 0.700), 17.5% and 24.0 (p = 0.292), 20.0% and 25.0% (p = 0.017) in Group 0 and Group 1 respectively.

DISCUSSION AND CONCLUSION

The results show that a short abstinence in severe OAT patients allows us to obtain spermatozoa with better motility. The request for a second semen sample in couples with extreme semen parameters is a valid and simple strategy that helps to achieve the same probability of pregnancy compared to a Control Group. Furthermore, it allows us to utilize fresh spermatozoa avoiding the need to resort to cryopreserved reserves or testicular surgery.

Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations

We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations. Of these, 13 recommendations concern technical aspects of sperm DNA fragmentation testing, including pre-analytical information, clinical thresholds and interpretation of results. The remaining 28 recommendations relate to indications for sperm DNA fragmentation testing and clinical management. Clinical scenarios like varicocele, unexplained infertility, idiopathic infertility, recurrent pregnancy loss, intrauterine insemination, in vitro fertilisation/intracytoplasmic sperm injection, fertility counselling for men with infertility risk factors and sperm cryopreservation have been contemplated. The bulk evidence supporting the recommendations has increased in recent years, but it is still of moderate to low quality. This guideline provides clinicians with advice on best practices in sperm DNA fragmentation testing. Also, recommendations are provided on possible management strategies to overcome infertility related to sperm DNA fragmentation, based on the best available evidence. Lastly, we identified gaps in knowledge and opportunities for research and elaborated a list of recommendations to stimulate further investigation.

One day is better than four days of ejaculatory abstinence for sperm function

According to the World Health Organization guidelines, ejaculatory abstinence (EA) of 2–7 days is recommended for semen analysis. This study aimed to determine how seminal quality may be affected by two EA periods from the same man. Seminal samples from 65 men were evaluated by conventional semen analysis and qualitative characteristics after 1 and 4 days of EA (two samples/man). The semen was qualitatively analyzed by examining oxidative activity (intracellular and seminal plasma), sperm function (acrosome integrity, mitochondrial activity, and nuclear DNA integrity), and epididymal function. As expected, samples collected after 1 day of EA showed a decrease in volume and sperm total number compared to samples collected after 4 days of EA. The sperm motility of the samples collected after 1 day of EA was better compared to samples collected after 4 days of EA. Oxidative activity measured was lower after 1 day of EA compared with those measured after 4 days of EA. With regards to sperm function, samples collected after 1 day of EA showed an increase in acrosome integrity, mitochondrial activity, and nuclear DNA integrity compared with samples collected after 4 days of EA. Epididymal function showed no difference between the two-time points. Although samples collected after 4 days of EA showed better results for sperm quantity, samples collected after 1 day of EA showed better qualitative results, including motility, oxidative activity, and sperm function. Thus, it can be concluded that sperm storage at the epididymal tail may make spermatozoa more susceptible to oxidative damage.

Collecting semen samples at home for IVF/ICSI does not negatively affect the outcome of the fresh cycle

Research question

Does the site of semen collection influence IVF/intracytoplasmic sperm injection (ICSI) cycle outcome?

Design

Retrospective study performed at the University Medical Centre Ljubljana, including all stimulated and modified natural IVF/ICSI cycles (with at least one oocyte retrieved) performed in 2019 with fresh ejaculated semen samples. IVF/ICSI cycle outcomes, in terms of oocytes, embryos and pregnancy rates according to site of semen sample collection (at home or at clinic) were evaluated.

Results

Samples collected at clinic had significantly lower sperm concentration (median [interquartile range, IQR], 50 [20–100] million/ml versus 70 [30–100] million/ml, adjusted odds ratio [OR] 0.001, 95% confidence interval [CI] 1.574  ×  10^–6 to 0.196, P = 0.012) and motility (60 [50–70]% versus 70 [50–70]%, adjusted OR 0.034, 95% CI 0.002 to 0.563, P = 0.018, adjusted for age). There was no difference in total sperm count, semen volume or sperm morphology, or women's age (36 [32–39] versus 36 [33–39] years) and men's age (37 [34–41] versus 38 [34–42] years), between semen samples collected at clinic versus at home. When all IVF/ICSI cycles were analysed together using generalized estimating equation analysis, no significant difference in cycle outcomes attributed to site of semen sample collection was observed. There were also no significant differences in cycle outcomes when only first cycles were analysed.

Conclusions

Collecting semen samples at home has a positive effect on sperm quality (sperm concentration and motility were higher), but no significant differences in cycle outcomes are observed when these samples are used in IVF/ICSI cycles. Therefore, it is suggested that collecting semen samples at home for IVF/ICSI procedures is safe and has no negative effect on treatment outcomes.

Effect of ejaculatory abstinence period on sperm DNA fragmentation and pregnancy outcome of intrauterine insemination cycles: A prospective randomized study

PURPOSE

To evaluate the effect of the ejaculatory abstinence period on sperm DNA fragmentation and pregnancy rates in IUI cycles.

METHODS

One hundred and twenty couples with unexplained infertility were prospectively randomized into two groups on the second day of their cycle. In group A, patients had 1-day ejaculatory abstinence period; in group B patients had 3-day ejaculatory abstinence period. Each patient was stimulated with gonadotropins, and IUI was performed. The primary outcome measure was clinical pregnancy and sperm DNA fragmentation rate.

RESULTS

The pregnancy rate was 17.3% and 18.5% in group A and group B, respectively. No significant difference was found among the groups (p = 0.803). The sperm DNA fragmentation rate for group A (20.71 ± 11.01) and group B (23.78 ± 12.64) were almost similar (p = 0.187). The sperm DNA fragmentation rate was 24.89 ± 12.89 in pregnant couples and 21.71 ± 11.69 in non-pregnant couples (p = 0.288).

CONCLUSION

Even after a short abstinence period of 1 day, compared to the standard abstinence period of 3 days, pregnancy rates are similar among unexplained infertility couples undergoing ovarian stimulation and IUI.

CLINICALTRIALS

The study was registered at ClinicalTrials.gov with ID NCT04361292. Date of registration: 27 April 2020. The study was registered retrospectively.

Diagnostic value of routine semen analysis in clinical andrology

Infertility is a major health issue affecting over 48.5 million couples around the world, with the male factor accounting for about 50% of the cases. The conventional semen analysis recommended by the World Health Organization (WHO) is the cornerstone in the evaluation of male fertility status. It includes macroscopic and microscopic evaluation of the ejaculate, which reflects the production of spermatozoa in the testes, the patency of the duct system and the glandular secretory activity. Evaluation of seminal fructose, sperm vitality and leucocytes (Endtz test) are useful adjuncts to semen analysis that provide information on specific clinical conditions. Though several computer-assisted sperm analysis (CASA) systems have been developed, conventional methods for semen analysis are still widely accepted in clinical practice. This review summarises the conventional techniques used in routine semen analysis and their diagnostic value in clinical andrology.