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

Mitochondrial activator BGP-15 protects sperm quality against oxidative damage and improves embryo developmental competence

OBJECTIVE

To study the efficacy of mitochondrial activator BGP-15 to preserve sperm quality and competence against cellular damage.

DESIGN

Spermatozoa from mice or humans were treated in vitro with BGP-15, and sperm quality markers were assessed. Spermatozoa from young (8-12 weeks old) or reproductively old (>14 months old) mice were treated with BGP-15 for 1 hour and assessed for sperm quality and preimplantation embryo development after in vitro fertilization. The safety of BGP-15 on offspring outcomes was assessed through embryo transfers. In parallel studies, spermatozoa from healthy (not infertile) men were incubated in hydrogen peroxide, to induce oxidative stress, plus increasing doses of BGP-15, and sperm quality was evaluated. Spermatozoa from patients undergoing assisted reproductive technology (ART) treatment were incubated in the optimized dose of BGP-15 for 30 minutes, and sperm quality was assessed.

SUBJECTS AND ANIMALS

C57BL/6 mice (N = 4-15 per group) for sperm quality and embryo development. CBAF1 mice (n = 6 per group) produced embryos for transfer. Human spermatozoa were from men with no infertility diagnosis (n = 14-20) or men undergoing ART (n = 33) at a local fertility clinic.

EXPOSURE

Mouse spermatozoa were treated with 10-μM BGP-15. Human spermatozoa were treated with BGP-15 at doses from 1 to 100 μM.

MAIN OUTCOME MEASURES

Sperm quality measures (mouse and human) included motility, mitochondrial membrane potential (JC-1 dye), deoxyribonucleic acid (DNA) fragmentation ("HALO" assay), and DNA oxidation (8-oxoguanine immunodetection). Mouse embryo and offspring measures included on-time development after in vitro fertilization, morphokinetic analysis, and blastocyst inner cell mass and trophectoderm cell number, and growth and development from birth to 21 days postnatally.

RESULTS

BGP-15 increased sperm motility and mitochondrial membrane potential and decreased DNA oxidation in old mice. BGP-15 improved on-time development of 2-cell and blastocyst embryos and increased the inner cell mass blastomere number. Embryos from BGP-15-treated mouse spermatozoa produced normal offspring. In human spermatozoa subjected to in vitro oxidative stress, BGP-15 increased motility by 45% and prevented DNA fragmentation (by 45%) and oxidative damage (by 60%). In spermatozoa from men attending a fertility clinic, BGP-15 increased motility by 12% and reduced both DNA oxidation and fragmentation by >20%.

CONCLUSION

BGP-15 protects sperm against cellular damage and has the potential to improve ART outcomes.

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.

Influence of two collection frequency intervals on sperm quality of standard and miniature bull Terriers during short breeding periods: A clinical field study

Background and Aims

The quality of canine sperm can be influenced by many factors, such as breed, body weight, age, ejaculatory frequency, nutrition, and environment. In the UK, it is common practice for standard Bull Terriers (SBT) and miniature Bull Terriers (MBT) to require male donors during a short breeding period. The aim of this study was to evaluate the effect of semen collection frequency on ejaculate volume and nine sperm parameters in SBT and MBT males, considering age and body condition score (BCS).

Materials and Methods

Ejaculates from six adult SBTs and four MBTs were collected 5 times at two consecutive intervals (Time Series [TS]1, 24 h vs. TS2, 48 h), 1 week apart. Ejaculate volume, concentration, total output, viability (live sperm), subjective total motility, vigor, and total morphological defects, including head, midpiece, and tail defects of sperm, were evaluated. A multivariable mixed linear model for repeated measures was used to analyze the effects of semen collection frequency, age, breed, and BCS on ejaculate volume and sperm parameters.

Results

Semen collection frequency, age, and, to a lesser extent, breed, and BCS significantly affected sperm parameters. Semen collection frequency affected all sperm parameters (p < 0.05) but not ejaculate volume (p > 0.05). Total sperm output, sperm vigor, total motility, and tail defects decreased (p < 0.05) at the end of TS1. However, sperm parameters remained relatively constant (p > 0.05) in TS2 between semen collection sessions. Overall, poorer sperm parameters were observed in older dogs (aged 5-8 years) than in younger dogs (aged 4 years). MBT produced less (p < 0.001) ejaculate volume (3.2 ± 0.2 mL vs. 4.3 ± 0.2 mL: Least Squares Mean ± Standard Error of Mean), lower total sperm output (221.8 ± 19.2 × 106 vs. 348.6 ± 19.2 × 106) and lower total morphological defects (25.0 ± 1.1% vs. 31.3 ± 0.9%), and a higher percentage of live sperm (77.0 ± 1.4% vs. 71.7 ± 1.1%) than SBT. In addition, a BCS of 4 positively influenced (p < 0.05) viability, vigor, and total sperm motility.

Conclusion

Despite differences in age, breed, and BCS, better sperm parameter values were observed in all semen collection sessions. However, intensive semen collection (TS1) appears to be less effective in maintaining good sperm quality. For breeding or artificial insemination purposes, a 48-h interval between collection sessions is recommended for both breeds. The results of this study could be used to further optimize assisted reproductive technologies in both breeds.

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.

Effects of a short abstinence period on sperm quality in oligozoospermic men

OBJECTIVE

The aim of this study was to compare semen parameters and sperm DNA fragmentation (SDF) and explore the relationship between semen parameters and SDF between 2 and 7 days of abstinence and a short abstinence period (within 4 hours) in oligozoospermic infertile patients.

METHODS

Two semen samples were collected from infertile oligozoospermic men (n=34) after an abstinence period of 2 to 7 days and within 4 hours, respectively. Sperm parameters were compared between the two abstinence duration groups, including semen volume, sperm concentration, total sperm count, sperm motility, total motile sperm count (TMSC), morphology, and SDF.

RESULTS

The semen volume, concentration, and total sperm count were significantly decreased after 4 hours of abstinence than after 2 to 7 days of abstinence, with median differences of 1.2 mL (p<0.001), 2×106/mL (p=0.011), and 9.6×106/ejaculation (p<0.001), respectively. TMSC was significantly lower after a short abstinence, with a median difference of 4.24×106/ejaculate (p<0.001). However, there were no significance differences in the percentage of motility, the SDF, and the percentage of sperm with normal morphology. Interestingly, volume, concentration, total sperm count, sperm motility, and SDF, but not TMSC, exhibited significant linear correlations between the two abstinence groups in univariate regression analysis, except for TMSC.

CONCLUSION

In oligozoospermic men, the volume, concentration, and total sperm count were significantly lower after a short abstinence period, but without adverse effects on sperm motility and SDF.

Effect of vitamin D metabolites and gene expression of vitamin D receptor, and 1-alpha-hydroxylase related to the sperm quality

The incidence of male fertility disorders has increased greatly due to various genetic and lifestyle factors. Recently, it has been hypothesized that vitamin D may be involved with idiopathic infertility. The goal of the study was to determine the effect and relationship between blood vitamin D metabolites, intracellular sperm vitamin D levels, and gene expression of 1-α-hydroxylase and VDR, with regard to semen quality. Seventy volunteers aged 25-45 were involved in the study. According to spermogram analysis, participants were stratified into normozoospermic control group, non-normozoospermic target group, and oligoasthenoteratozoospermic group. Vitamin D metabolites (total 25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol) in blood and spermatozoa were determined by ELISA. Free and bioavailable 25-hydroxycholecalciferol were calculated using the Vermeulen equation. mRNA expression of VDR and 1-α hydroxylase was evaluated by qPCR. Free and bioavailable 25-hydroxycholecalciferol were significantly higher in the control group compared to the target group and compared to the oligoasthenoteratozoospermic group . Intracellular sperm 1,25-dihydroxycholecalciferol was higher in the control group compared to the target group. The mRNA levels of 1- α-hydroxylase were significantly higher in the control samples, while VDR expression was significantly higher in the target group. Significant positive correlations were established between free and bioavailable 25-hydroxycholecalciferol with sperm motility and morphology. Vitamin D metabolites in blood and intracellular sperm 1,25-dihydroxycholecalciferol seem to exert beneficial effects on sperm motility and morphology. Regarding sperm quality, these effects are more pronounced in the free and bioavailable 25OHD compared to the total 25OHD in blood. Higher expression of 1-α-hydroxylase likely leads to higher intracellular levels of 1,25-dihydroxycholecalciferol, which could contribute to sperm motility and morphology. Higher VDR expression may be a compensatory mechanism related to lower intracellular sperm 1,25-dihydroxycholecalciferol.

Understanding the impact of varicocele on sperm capacitation

OBJECTIVE

To study the relationship between the seminal sample quality of men with varicocele and sperm capacitation.

DESIGN

Cross-sectional observational study.

SETTING

Academic hospital.

PATIENT(S)

Seventy-six men (19 control and 57 with varicocele) were analyzed.

INTERVENTION(S)

Semen samples were submitted to a discontinuous density gradient for sperm selection. Sperm capacitation was induced using a human tubal fluid medium supplemented with bovine serum albumin.

MAIN OUTCOME MEASURE(S)

After capacitation induction, the sperm were assessed by capacitation state, computer-assisted sperm motility, mitochondrial activity, membrane integrity, acrosome reaction, and intracellular oxidative stress.

RESULT(S)

The capacitation period increased sperm motility, showing an increase in the average path velocity and a decrease in the straightness compared with sperm before capacitation (paired analysis). After capacitation, the rate of capacitated sperm, motility, and mitochondrial activity showed differences between groups (control and varicocele). The varicocele group showed lower mitochondrial activity and capacitation than the control group. On the other hand, no significant differences were observed in the other variables evaluated.

CONCLUSION(S)

Varicocele men showed less viable sperm and mitochondrial activity than control men after capacitation sperm. The induction of capacitation altered motility by increasing path velocity and decreasing straightness in all of the studied groups, evidencing the occurrence of hyperactivation.

Trends in sperm quality by computer-assisted sperm analysis of 49,189 men during 2015-2021 in a fertility center from China

Background

Sperm quality, including semen volume, sperm count, concentration, and total and progressive motility (collectively, "semen parameters"), has declined in the recent decades. Computer-assisted sperm analysis (CASA) provides sperm kinematic parameters, and the temporal trends of which remain unclear. Our objective is to examine the temporal trend of both semen parameters and kinematic parameters in Shanghai, China, in the recent years.

Methods

This retrospective study analyzed semen parameters and kinematic parameters of 49,819 men attending our reproductive center by using CASA during 2015-2021. The total sample was divided into two groups: samples that surpassed the WHO guideline (2010) low reference limits ("above reference limit" group, ARL; n = 24,575) and samples that did not ("below reference limit" group, BRL; n = 24,614). One-way analysis of variance, Kruskal-Wallis test, independent samples t-test, and covariance analysis were used to assess the differences among groups. Year, age, and abstinence time were included in the multiple linear regression model of the ARL group to adjust the confounders and depict the trends in sperm quality.

Results

Among all the total sample and the ARL and BRL groups, the age of subjects increased in recent years. Semen volume and sperm count showed declined tendency with years in the total sample, the ARL and BRL groups, and the subgroup of age or abstinence time, whereas sperm velocities showed increased tendency with years on the contrary. The multiple linear regression model of the ARL group, adjusting for age and abstinence time, confirmed these trends. Semen volume (β1= -0.162; CI: -0.172, -0.152), sperm count (β1= -9.97; CI: -10.813, -9.128), sperm concentration (β1 = -0.535; CI: -0.772, -0.299), motility (β1 = -1.751; CI: -1.830, -1.672), and progressive motility (β1 = -1.12; CI: -0.201, -0.145) decreased with year, whereas curvilinear line velocity (VCL) (β1 = 3.058; CI: 2.912, 3.203), straight line velocity (VSL) (β1 = 2.075; CI: 1.990, 2.161), and average path velocity (VAP) (β1 = 2.305; CI: 2.224, 2.386) increased over time (all p < 0.001). In addition, VCL, VSL, and VAP significantly declined with age and abstinence time.

Conclusion

The semen parameters declined, whereas the kinematic parameters increased over the recent years. We propose that, although sperm count and motility declined over time, sperm motion velocity increased, suggesting a possible compensatory mechanism of male fertility.

Ejaculatory Abstinence Affects the Sperm Quality in Normozoospermic Men-How Does the Seminal Bacteriome Respond?

This study was designed to describe bacterial profiles of ejaculates collected following a long and short ejaculatory abstinence set in the context of changes in the conventional, oxidative, and immunological characteristics of semen. Two specimens were collected in succession from normozoospermic men (n = 51) following 2 days and 2 h, respectively. Semen samples were processed and analyzed according to the World Health Organization (WHO) 2021 guidelines. Afterwards, sperm DNA fragmentation, mitochondrial function, levels of reactive oxygen species (ROS), total antioxidant capacity, and oxidative damage to sperm lipids and proteins were evaluated in each specimen. Selected cytokine levels were quantified using the ELISA method. Bacterial identification by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry revealed that samples collected following two days of abstinence presented with a higher bacterial load and diversity, and a greater prevalence of potentially uropathogenic bacteria including Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. Only staphylococci and Escherichia coli remained present in specimens obtained after 2 h of abstinence. Whilst all samples accomplished the criteria set by WHO, a significantly higher motility (p < 0.05), membrane integrity (p < 0.05), mitochondrial membrane potential (p < 0.05), and DNA integrity (p < 0.0001) were detected following 2 h of ejaculatory abstinence. On the other hand, significantly higher ROS levels (p < 0.001), protein oxidation (p < 0.001), and lipid peroxidation (p < 0.01) accompanied by significantly higher concentrations of tumor necrosis factor alpha (p < 0.05), interleukin-6 (p < 0.01), and interferon gamma (p < 0.05) were observed in specimens collected after two days of abstinence. It may be summarized that shorter ejaculatory abstinence does not compromise sperm quality in normozoospermic men, while it contributes to a decreased occurrence of bacteria in semen which is accompanied by a lower probability of damage to spermatozoa by ROS or pro-inflammatory cytokines.

Effect of chronic sleep deprivation on acrosomal integrity and functional parameters of murine sperm

OBJECTIVE

To evaluate the effect of chronic sleep deprivation on sperm function quality in mice.

DESIGN

Experimental study.

SETTING

Not applicable.

ANIMALS

Spermatozoa from twenty-four 10-week-old C57BL/6J male mice.

INTERVENTION(S)

The sleep deprivation group underwent gentle handling for 6 hours for 5 consecutive days. The mice in the sleep recovery group were allowed to sleep during the 24-hour period after the sleep deprivation protocol.

MAIN OUTCOME MEASURE(S)

After euthanasia, the spermatozoa were collected for analysis. Sperm motility was evaluated using computer-assisted sperm analyzer. Intracellular superoxide anion (O₂^-) activity, acrosome integrity, mitochondrial activity, and DNA fragmentation assays were conducted afterward.

RESULT(S)

Sleep deprivation and sleep recovery groups presented a lower percentage of spermatozoa with an intact acrosome, compared with the respective control groups. Regarding DNA fragmentation, a decreased proportion of spermatozoa with Comet I class intact DNA was observed in the sleep recovery group, compared with the recovery control group. Beat cross frequency was increased in the sleep recovery group.

CONCLUSION(S)

Sleep deprivation can reduce sperm quality, impairing acrosome integrity. Sleep recovery decreased DNA integrity and increased beat cross frequency.

Pre-but not post-meiotic senescence affects sperm quality and reproductive success in the North African houbara bustard

Age-dependent reduction in reproductive success can arise due to multiple factors including a deterioration of reproductive physiology. Senescing males have been shown to produce ejaculates with poor sperm quality, which impinges on male reproductive success. In addition to individual age, gamete age can also affect male reproductive success. Accordingly, variance in male reproductive success can be due to pre-meiotic (referring to individual age) and post-meiotic senescence (sperm age). Here, we tested whether male senescence and sperm cell aging have additive or interactive effects on male reproductive success in a bird with a promiscuous mating system, the North African houbara bustard. To assess the effect of pre-meiotic aging, we compared male reproductive success between two age classes (3-6- and 12–16-year-old). To infer the effect of post-meiotic aging, male ejaculates were collected at three-time intervals following a common initial collection (day 1, 5, and 10). Therefore, day 1 ejaculates are supposed to contain younger sperm than day 5 and 10 ejaculates. Following controlled artificial inseminations, reproductive success was assessed using three fitness-linked traits (hatching success, chick growth rate and survival). In addition to reproductive output, we also assessed whether pre- and post-meiotic aging affected a wide range of sperm and ejaculate traits. In agreement with previous reports, we found that males in the older age class produced less sperm with poorer motility compared to young individuals. However, contrary to the prediction, we found that ejaculates collected at day 5 and 10 tended to have better sperm traits such as motility and velocity. The results on sperm traits were generally mirrored in the effect on reproductive success since young males produced offspring that grew faster and had better survival during the first month of life, and eggs fertilized by sperm collected at day 5 had the highest hatching success. In any of the models, there was evidence for interactive effects of male and sperm age. Overall, these results confirm the role of pre-meiotic aging on male reproductive success. The lack of evidence for sperm aging could come from the experimental design but might also reflect the pattern of mating frequency in a species with a lek-based mating system.

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.

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.

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.

Oxidative Stress and Male Infertility: Evidence From a Research Perspective

Male fertility potential can be influenced by a variety of conditions that frequently coincide. Spermatozoa are particularly susceptible to oxidative damage due to their limited antioxidant capacity and cell membrane rich in polyunsaturated fatty acids (PUFAs). The role of oxidative stress (OS) in the etiology of male infertility has been the primary focus of our Stellenbosch University Reproductive Research Group (SURRG) over the last 10 years. This review aims to provide a novel insight into the impact of OS on spermatozoa and male reproductive function by reviewing the OS-related findings from a wide variety of studies conducted in our laboratory, along with those emerging from other investigators. We will provide a concise overview of the production of reactive oxygen species (ROS) and the development of OS in the male reproductive tract along with the physiological and pathological effects thereof on male reproductive functions. Recent advances in methods and techniques used for the assessment of OS will also be highlighted. We will furthermore consider the current evidence regarding the association between OS and ejaculatory abstinence period, as well as the potential mechanisms involved in the pathophysiology of various systemic diseases such as obesity, insulin resistance, hypertension, and certain mental health disorders which have been shown to cause OS induced male infertility. Finally, special emphasis will be placed on the potential for transferring and incorporating research findings emanating from different experimental studies into clinical practice.

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.

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.