Beneficial effect of microsurgical varicocelectomy on human sperm DNA integrity

Effects of Varicocele Repair on Sperm DNA Fragmentation and Seminal Malondialdehyde Levels in Infertile Men with Clinical Varicocele: A Systematic Review and Meta-Analysis

PURPOSE

Varicoceles can be a source of elevated seminal oxidative stress (OS) and sperm DNA fragmentation (SDF). However, it remains unclear whether varicocele repair (VR) could reduce these parameters. This systematic review and meta-analysis (SRMA) aims to investigate the impact of VR on SDF and seminal malondialdehyde (MDA).

MATERIALS AND METHODS

A literature search was performed in Scopus, PubMed, Ovid, Embase, and Cochrane databases. This SRMA included randomized controlled trials and observational studies reporting the pre- and postoperative levels of SDF and seminal OS in infertile men with clinical varicocele that underwent VR. Subgroup analyses included techniques of VR and SDF testing. The effect size was expressed as standardized mean difference (SMD).

RESULTS

Out of 1,632 abstracts assessed for eligibility, 29 studies with 1,491 infertile men were included. The analysis showed a significant reduction in SDF after VR, compared to preoperative values (SMD -1.125, 95% confidence interval [CI] -1.410, -0.840; p<0.0001) with high inter-study heterogeneity (I²=90.965%). Reduction in SDF was evident with microsurgical technique and non-microsurgical inguinal approaches (SMD -1.014, 95% CI -1.263, -0.765; p<0.0001, and SMD -1.495, 95% CI -2.116, -0.873; p<0.0001), respectively. Reduction in SDF was significant irrespective of testing was done by sperm chromatin dispersion (SMD -2.197, 95% CI -3.187, -1.207; p<0.0001), sperm chromatin structure assay (SMD -0.857, 95% CI -1.156, -0.559; p<0.0001) or TUNEL (SMD -1.599, 95% CI -2.478, -0.719; p<0.0001). A significant decrease in seminal MDA levels was observed following VR (SMD -2.450, 95% CI -3.903 to -0.997, p=0.001) with high inter-study heterogeneity (I²=93.7%).

CONCLUSIONS

Using pre- and post-intervention data, this SRMA indicates a significant reduction in SDF and seminal MDA levels in infertile men with clinical varicocele treated with VR. These findings may have important implications for the future management of this selected group of infertile patients.

Effect of varicocele and varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele

Varicocele is the leading cause of male infertility. It can affect sperm quantity and quality through various non-mutually exclusive pathophysiological mechanisms, mainly oxidative stress. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress and harm the sperm's DNA. Excessive sperm DNA breaks, so-called sperm DNA fragmentation, result from the oxidative stress cascade and are commonly found in the ejaculates of men with varicocele and fertility-related issues. Measuring sperm DNA fragmentation can provide valuable information on the extent of harm and might help select candidates for surgical treatment. Varicocelectomy is beneficial for alleviating oxidative stress-associated infertility and improving sperm DNA integrity. However, reproductive outcomes of infertile men with elevated sperm DNA fragmentation rates and surgically treated varicoceles remain poorly studied, and there is a need for well-designed trials to determine the impact of sperm DNA fragmentation reduction on natural and medically assisted reproduction.

Does Varicocele Repair Improve Conventional Semen Parameters? A Meta-Analytic Study of Before-After Data

PURPOSE

The purpose of this meta-analysis is to study the impact of varicocele repair in the largest cohort of infertile males with clinical varicocele by including all available studies, with no language restrictions, comparing intra-person conventional semen parameters before and after the repair of varicoceles.

MATERIALS AND METHODS

The meta-analysis was performed according to PRISMA-P and MOOSE guidelines. A systematic search was performed in Scopus, PubMed, Cochrane, and Embase databases. Eligible studies were selected according to the PICOS model (Population: infertile male patients with clinical varicocele; Intervention: varicocele repair; Comparison: intra-person before-after varicocele repair; Outcome: conventional semen parameters; Study type: randomized controlled trials [RCTs], observational and case-control studies).

RESULTS

Out of 1,632 screened abstracts, 351 articles (23 RCTs, 292 observational, and 36 case-control studies) were included in the quantitative analysis. The before-and-after analysis showed significant improvements in all semen parameters after varicocele repair (except sperm vitality); semen volume: standardized mean difference (SMD) 0.203, 95% CI: 0.129-0.278; p<0.001; I²=83.62%, Egger's p=0.3329; sperm concentration: SMD 1.590, 95% CI: 1.474-1.706; p<0.001; I²=97.86%, Egger's p<0.0001; total sperm count: SMD 1.824, 95% CI: 1.526-2.121; p<0.001; I²=97.88%, Egger's p=0.0063; total motile sperm count: SMD 1.643, 95% CI: 1.318-1.968; p<0.001; I²=98.65%, Egger's p=0.0003; progressive sperm motility: SMD 1.845, 95% CI: 1.537%-2.153%; p<0.001; I²=98.97%, Egger's p<0.0001; total sperm motility: SMD 1.613, 95% CI 1.467%-1.759%; p<0.001; l2=97.98%, Egger's p<0.001; sperm morphology: SMD 1.066, 95% CI 0.992%-1.211%; p<0.001; I²=97.87%, Egger's p=0.1864.

CONCLUSIONS

The current meta-analysis is the largest to date using paired analysis on varicocele patients. In the current meta-analysis, almost all conventional semen parameters improved significantly following varicocele repair in infertile patients with clinical varicocele.

The effect of different doses of nonylphenol on the blood-testicular barrier integrity, hormone level, and DNA damage in the testes of rats

Determining the molecular characteristics of the damage caused by NP exposure in the testis is very important for understanding the source of the damage and developing treatment methods accordingly. Therefore, in this study, it is aimed to evaluate the toxic effects that different doses of NP may cause in the testis, including blood-testicular barrier integrity and sperm DNA damage. For this purpose, 50 adult male Wistar albino rats were used in the study. Low, medium, and high-dose NP groups and the corn oil group were formed. After NP administration at determined doses for 15 days, the testis tissue taken under anesthesia was fixed in formaldehyde. Paraffin blocks were embedded using the routine histological tissue follow-up method. Histopathological and immunohistochemical analyses were performed by taking 5 μm thick sections from paraffin blocks. The other testicular tissue was taken for the Western blot, Elisa, and comet methods, and the findings of sperm DNA analysis and the blood-testicular barrier were examined. NP caused the seminiferous epithelium to be disorganized and have significantly fewer cells in the testes of rats in different dose NP-induced groups. Compared with the control group, mTOR, Cx43, SCF, and HSP70 protein levels were decreased, while the expression of MMP-9 levels was increased in the different NP dose groups. Furthermore, tissue testosterone and inhibin B levels and SF-1 immunoreactivity intensity gradually decreased depending on the dose increase of NP. DNA damage of testicular tissues were increased in NP groups depending on NP dose. These results suggest that it is evident that NP, a commonly used industrial chemical, is an endocrine disrupting chemical (EDC) with estrogenic activity exerting adverse effects on health and that urgent measures are needed regarding the use.

Testicular heat stress, a historical perspective and two postulates for why male germ cells are heat sensitive

Herein, we compare the different experimental regimes used to induce testicular heat stress and summarise their impact on sperm production and male fertility. Irrespective of the protocol used, scrotal heat stress causes loss of sperm production. This is first seen 1-2 weeks post heat stress, peaking 4-5 weeks thereafter. The higher the temperature, or the longer the duration of heat, the more pronounced germ cell loss becomes, within extreme cases this leads to azoospermia. The second, and often underappreciated impact of testicular hyperthermia is the production of poor-quality spermatozoa. Typically, those cells that survive hyperthermia develop into morphologically abnormal and poorly motile spermatozoa. While both apoptotic and non-apoptotic pathways are known to contribute to hyperthermic germ cell loss, the mechanisms leading to formation of poor-quality sperm remain unclear. Mechanistically, it is unlikely that testicular hyperthermia affects messenger RNA (mRNA) abundance, as a comparison of four different mammalian studies shows no consistent single gene changes. Using available evidence, we propose two novel models to explain how testicular hyperthermia impairs sperm formation. Our first model suggests aberrant alternative splicing, while the second model proposes a loss of RNA repression. Importantly, neither model requires consistent changes in RNA species.

Pathological Roles of Reactive Oxygen Species in Male Reproduction

Reactive oxygen species (ROS) are free radicals that have at least one unpaired electron and play specific roles in the human body. An imbalance of ROS and antioxidant levels gives rise to a condition called oxidative stress. High levels of ROS in the male reproductive tract can interfere with its normal functioning and can even pose as toxic to the sperm, inhibiting sperm functioning (including motility) and metabolism. Oxidative stress resulting from ROS and lipid peroxidation is one of the major causes of male infertility including infertility in varicocele patients. These may cause DNA and peroxidative damage and apoptosis. Production of ROS in excess also leads to erectile dysfunction (ED). In recent years, studies have also linked oxidative stress with the development, progress, and therapy response of prostate cancer patients. The present study summarizes the pathological roles of ROS in male reproductive problems such as infertility, ED, and prostate cancer and also provide an insight into the probable mechanism through which ROS exert their pathological impact.

Inflammation and Oxidative Stress in Seminal Plasma: Search for Biomarkers in Diagnostic Approach to Male Infertility

Oxidative and inflammatory damage underlie several conditions related to male infertility, including varicocele. Free light chains of immunoglobulins (FLCs) are considered markers of low-grade inflammation in numerous diseases. Coenzyme Q10 (CoQ10), a lipidic antioxidant and anti-inflammatory compound, is involved in spermatozoa energy metabolism and motility. We aimed to evaluate FLCs’ seminal levels in patients with varicocele in comparison to control subjects and to correlate them with CoQ10 and Total Antioxidant Capacity (TAC) in human semen. Sixty-five patients were enrolled. Semen analysis was performed; patients were divided into three groups: controls, 12 normozoospermic patients, aged 34 (33–41) years; varicocele (VAR), 29 patients, aged 33 (26–37) years; and idiopathic, 24 oligo-, astheno- and oligoasthenozoospermic patients aged 37 (33.5–40.5) years. FLCs (κ and λ) were assayed by turbidimetric method; CoQ10 by HPLC; TAC by spectrophotometric method. λ FLCs showed a trend toward higher levels in VAR vs. controls and the idiopathic group. VAR showed a trend toward lower κ FLCs levels vs. the other two groups. When comparing κ/λ ratio, VAR showed significantly lower levels vs. controls and idiopathic. Moreover, CoQ10 seminal levels showed higher levels in VAR and idiopathic compared to controls. Data reported here confirm lower levels of κ/λ ratio in VAR and suggest a possible application in personalized medicine as clinical biomarkers for male infertility.

Effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation (SDF) rates in infertile men with clinical varicocele.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Infertile men with clinical varicocele subjected to varicocelectomy.

INTERVENTION(S)

Systematic search using PubMed/Medline, EMBASE, Cochrane's central database, Scielo, and Google Scholar to identify relevant studies published from inception until January 2021. We included studies comparing SDF rates before and after varicocelectomy in infertile men with clinical varicocele.

MAIN OUTCOME MEASURE(S)

The primary outcome was the difference between the SDF rates before and after varicocelectomy. A meta-analysis of weighted data using random-effects models was performed. Results were reported as weighted mean differences (WMD) with 95% confidence intervals (CIs). Subgroup analyses were performed on the basis of the SDF assay, varicocelectomy technique, preoperative SDF levels, varicocele grade, follow-up time, and study design.

RESULT(S)

Nineteen studies involving 1,070 patients provided SDF data. Varicocelectomy was associated with reduced postoperative SDF rates (WMD -7.23%; 95% CI: -8.86 to -5.59; I² = 91%). The treatment effect size was moderate (Cohen's d = 0.68; 95% CI: 0.77 to 0.60). The pooled results were consistent for studies using sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, sperm chromatin dispersion test, and microsurgical varicocele repair. Subgroup analyses showed that the treatment effect was more pronounced in men with elevated vs. normal preoperative SDF levels, but the impact of varicocele grade remained equivocal. Meta-regression analysis demonstrated that SDF decreased after varicocelectomy as a function of preoperative SDF levels (coefficient: 0.23; 95% CI: 0.07 to 0.39).

CONCLUSION(S)

We concluded that pooled results from studies including infertile men with clinical varicocele indicated that varicocelectomy reduced the SDF rates. The treatment effect was greater in men with elevated (vs. normal) preoperative SDF levels. Further research is required to determine the full clinical implications of SDF reduction for these men.

Seminal inflammasome activity in the adult varicocele

Varicocele has been hypothesized to lead to seminal inflammation, which in turn interferes with sperm function. Thus, the aim of this study was to investigate the role of inflammatory cytokines in the pathogenesis of decreased semen quality observed in adult men with varicocele, and to determine if varicocelectomy corrects these potential alterations. A prospective study was carried out including fifteen control men without varicocele and with normal semen quality and 15 men with varicocele with surgical indication. Men with varicocele grades II or III underwent microsurgical subinguinal varicocelectomy. Controls collected one semen sample and men with varicocele collected one before and one 6 months after the surgery. Semen analysis, sperm function, and seminal lipid peroxidation levels were assessed. Seminal plasma inflammasome activity was evaluated by ELISA assays for IL-1β, IL-18 and caspase-1 and by Western blotting for ASC (apoptosis-associated speck-like protein). Groups were compared by an unpaired Student's T test. Varicocelectomy samples were compared using a paired Student's T test (α = 5%). Men with varicocele had decreased semen quality, and increased seminal IL-1β levels, when compared to control men. Varicocelectomy decreased levels of caspase-1, IL-18, and IL1β. Thus, varicocelectomy improves sperm morphology and decreases seminal plasma inflammatory activity, after a six-month post-operative period.

European Association of Urology Guidelines Panel on Male Sexual and Reproductive Health: A Clinical Consultation Guide on the Indications for Performing Sperm DNA Fragmentation Testing in Men with Infertility and Testicular Sperm Extraction in Nonazoospermic Men

Accumulating evidence has highlighted the contribution of oxidative stress and sperm DNA fragmentation (SDF) in the pathophysiology of male infertility. SDF has emerged as a novel biomarker of risk stratification for patients undergoing assisted reproductive technologies. Studies have also supported the use of testicular over ejaculated sperm at the time of intracytoplasmic sperm injection, as testicular sperm may have lower SDF than ejaculated samples. The European Association of Urology Working Panel on Male Sexual and Reproductive Health provides an evidence-based consultation guide on the indications for SDF testing in male infertility and also for testicular sperm extraction (TESE) in nonazoospermic men. We present the limitations and advantages of SDF testing and a framework to ensure that it is appropriately utilised in clinical practice. Furthermore, we critically appraise the current literature advocating the use of TESE in nonazoospermic men. PATIENT SUMMARY: This article reviews the evidence supporting the use of sperm DNA fragmentation testing in the assessment of male infertility and testicular sperm extraction in nonazoospermic men.

Best time to wait for the improvement of the sperm parameter after varicocelectomy: 3 or 6 months?

OBJECTIVE

To estimate the duration of time required following varicocelectomy to wait for the improvements of semen parameters. Therefore, we characterized the changes with the time in sperm parameters in men after varicocelectomy.

MATERIALS AND METHODS

In this prospective cohort study we included consecutively observed men who underwent varicocelectomy between September 2017 and September 2018 in a referral academic hospital. Clinical data of the patients, as well as their semen parameters, were measured before surgery and at 3 and 6 months afterward.

RESULTS

In this study, a total of 100 men with average age of 29.5 ± 6.2 years were included. Mean sperm concentration and sperm motility significantly improved by 3 (p < 0.05), but not by 6 months following varicocelectomy. The semen volume and sperm with normal morphology were the same before and after surgery (p > 0.05). There was no statistically significant difference in the improvement of semen parameters when comparing 6 months to 3 months postoperatively (p > 0.05).

CONCLUSIONS

Sperm parameters (concentration and motility) improve by 3 months after varicocelectomy without further improvements. Consequently, physicians should decide quickly after 3-month of varicocelectomy if surgery has been not helpful and then plan other therapies, like assisted reproductive technology (ART) for managing infertility in couples.

Sperm DNA Fragmentation: A New Guideline for Clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Comparative analysis of tests used to assess sperm chromatin integrity and DNA fragmentation

Male infertility has a complex etiology, and many times, the cause is unknown. While routine semen analysis provides an overview of basic semen parameters, such as sperm concentration, motility, viability and morphology, a significant overlap of these parameters has been reported in fertile and infertile men. Moreover, conventional semen parameters do not reveal the cellular or molecular mechanisms of sperm dysfunctions leading to infertility. Therefore, sperm functional parameters, including sperm chromatin integrity, are evaluated to provide information on subtle sperm defects that are not routinely identified. Incomplete or defective sperm chromatin condensation increases the susceptibility of the sperm DNA to oxidative damage or other factors. To evaluate sperm chromatin integrity, different methods with varying degrees of diagnostic and prognostic capabilities are available. Among these assays, SCSA, TUNEL and SCD assays are most commonly used. While these assays rather evaluate the DNA directly for damages, the aniline blue and chromomycin A3 stains test for the quality of chromatin condensation. Thus, this review discusses and compares different methods used to evaluate sperm chromatin integrity and condensation, and their inclusion in the routine evaluation of the male infertility.

Conventional semen analysis and advanced sperm function tests in diagnosis and management of varicocele

Clinical varicoceles are a common cause of male infertility and affect sperm parameters as measured in a conventional semen analysis. Varicocelectomy has been shown in prospective studies to improve semen parameters in men with a clinical varicocele. Clinical varicoceles are also a well-known source of oxidative stress which may affect the quality of spermatozoa. Spermatozoa are particularly susceptible to oxidative stress due to a limited capacity for DNA repair. The susceptibility of spermatozoa to oxidative stress is modulated by a balance between ROS and antioxidants, which can be quantified by various laboratory assays. Varicocelectomy has been consistently shown to reduce both ROS and sperm DNA fragmentation, and various assays should be utilised in the diagnosis and treatment of infertile men with a clinical varicocele.

Interventions to Prevent Sperm DNA Damage Effects on Reproduction

Excessive oxidation and antioxidant imbalance resulting from several conditions may cause sperm DNA damage, which, in turn, affect male fertility, both natural and assisted. Sperm DNA damage transferred to the embryo might also affect the health of offspring. Several conditions associated with excessive oxidative stress are modifiable by the use of specific treatments, lifestyle changes, and averting exposure to environmental/occupational toxicants. Here, we discuss the strategies to reduce sperm DNA damage with a focus on clinical and surgical interventions.

HSPA1L and HSPA1B gene polymorphisms and haplotypes are associated with idiopathic male infertility in Iranian population

OBJECTIVE

Male infertility is a multifactorial disease resulting from the interaction between the genetic and environmental factors. Spermatogenic failure accounts for more than half of male infertility cases. Heat shock proteins (HSPs) are the molecular chaperones that are involved in different developmental stages of spermatogenesis. The current study was planned to investigate the role of HSPA1L rs2227956 and HSPA1B rs1061581 gene polymorphisms in idiopathic male infertility.

STUDY DESIGN

This case-control study was conducted on 516 subjects consisted of 308 patients with idiopathic male infertility and 208 age matched-(±5) control subjects. HSPA1L rs2227956 and HSPA1B rs1061581 polymorphisms were genotyped by PCR-RFLP method.

RESULTS

A significant association with male infertility was found for HSPA1L rs2227956 in genotypes (TT vs CT: OR = 2.049, 95% CI = 1.337-3.139, P = 0.001; TT vs CC: OR = 3.028, 95% CI = 1.100-8.332, P = 0.032). In the dominant genetic model, rs2227956C allele increased the risk of male infertility (OR = 2.049, 95% CI = 1.337-3.139, P = 0.001). Also, the results showed a significant association between the HSPA1B rs1061581GG genotype and male infertility (OR = 2.638, 95% CI: 1.001-4.486, P = 0.001). The rs1061581 G allele was a risk factor for male infertility (OR = 1.657, 95% CI = 1.278-2.148, P < 0.001). Haplotype analysis showed CG and TA (rs2227956/ rs1061581) haplotype affect the risk of male infertility (P < 0.001).

CONCLUSION

HSPA1L rs2227956 and HSPA1B rs1061581 gene polymorphisms are associated with susceptibility to idiopathic male infertility in Iranian population. Further studies in different ethnicity are necessary to confirm these results.

Abnormal Human Sperm Parameters Contribute to Sperm DNA Fragmentation in Men with Varicocele

PURPOSE

This study was performed to evaluate and compare threshold sperm parameters and sperm DNA fragmentation index (DFI), and further analyzed whether sperm DFI could be predicted from sperm parameters in men with varicocele.

MATERIALS AND METHODS

A total of 157 semen samples underwent both semen analysis and sperm DNA fragmentation (SDF) testing in men with varicocele. Sperm parameters were assessed using the World Health Organization guidelines. SDF testing was performed using the Halosperm kit. Sperm parameters and sperm DFI results were compared.

RESULTS

The overall sperm parameter results and sperm DFI showed normal values; however, the morphology value was at the lower limit of normal. High sperm DFI was associated with significantly lower motility and viability (p<0.001, respectively). Sperm motility and morphology were significantly higher in the higher sperm count group compared to the lower sperm count group (p<0.05), while sperm DFI was higher in the lower sperm count group (p<0.05). Sperm count and viability and sperm DFI were significantly associated with the quality of sperm motility (p<0.001). Sperm motility and sperm DFI were significantly different (p<0.001) between normal and abnormal sperm viability groups. Between normal and abnormal sperm morphology groups, sperm count, motility, and sperm DFI showed significant differences (p<0.001).

CONCLUSIONS

In this study, a correlation between SDF and sperm parameters was confirmed in men with varicocele. SDF may be contributing factors to sperm motility, viability, and morphology. Abnormal sperm count, motility, and viability showed high sperm DFI. Therefore, lower sperm parameters were indicative of increasing SDF in men with varicocele.

Effect of varicocelectomy and/or mast cells stabilizer on sperm DNA fragmentation in infertile patients with varicocele

This study aimed to assess the effect of varicocelectomy and/or mast cells (MCs) stabilizer on sperm DNA fragmentation in infertile men with varicocele (Vx). Overall, 120 infertile patients were randomized to three equal treatment arms; patients that underwent varicocelectomy, patients on 1 mg ketotifen twice daily for three months, and patients that underwent varicocelectomy followed with 1 mg ketotifen twice daily for three months. These patients were subjected to history taking, clinical examination, semen analysis, and estimation of sperm DNA fragmentation index (DFI). After 3 months, all investigated groups showed significant improvement regarding the mean total sperm count, sperm concentration, total sperm motility, and sperm normal forms percentage compared with the pre-treatment data. As well, the mean sperm DFI was significantly improved compared with the pre-treatment data; in men that underwent varicocelectomy (34.6% vs. 28.3%), in men on MC stabilizer only (33.4% vs. 27.8%), and in men that underwent varicocelectomy followed by MC stabilizer (34.3% vs. 25.1%). Sperm DFI improvement percentages showed the highest improvement in men that underwent varicocelectomy followed with MC stabilizer compared with the other two groups (26.8% vs. 18.2%, 16.8%). Sperm DFI improvement percentages showed significant increases in the infertile patients with Vx grade III compared to Vx grade II in all investigated groups. It is concluded that in infertile men associated with Vx and high sperm DFI, surgical repair followed with MCs stabilizer significantly improve sperm DFI compared with either surgical repair or MCs stabilizer alone.

Free-radical production after post-thaw incubation of ram spermatozoa is related to decreased in vivo fertility

The aim of the present study was to evaluate the effect of sperm reactive oxygen species (ROS) production and DNA changes on male fertility. For that purpose, six rams with significantly different pregnancy rates were used; these were classified as having high fertility, i.e. 59.4% average pregnancy rate, or low fertility, i.e. 23.1% average pregnancy rate. Sperm quality was assessed after a two-step process of sample thawing followed by an incubation of 2h, either in the freezing extender (37°C) or after dilution in synthetic oviductal fluid (SOF; 38°C, 5%CO2). Sperm viability (YO-PRO-1), ROS production (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein acetyl ester (CM-H2DCFDA)) and undamaged chromatin (sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling, chromomycin A3) were evaluated by flow cytometry. Although no significant differences in sperm viability were observed, our results showed increased ROS production during incubation in the freezing extender as well as in SOF medium. Comparison between fertility groups showed significant differences in ROS production after 2h of incubation for the two treatments. Regarding DNA integrity, our results showed no significant differences either between treatments and incubation times or fertility groups. Linear regression analysis showed that ROS production determined by CM-H2DCFDA was a good indicator parameter for in vivo male fertility of SOF-incubated samples, yielding a fair correlation between both parameters (r=-0.92). These results indicate that detection of ROS production by CM-H2DCFDA and flow cytometry after 2h of incubation in SOF could be a useful procedure for predicting fertility of ram spermatozoa.

The impact of coexisting sperm DNA fragmentation and seminal oxidative stress on the outcome of varicocelectomy in infertile patients: A prospective controlled study

OBJECTIVES

To study the relationship between sperm DNA fragmentation (SDF) and reactive oxygen species (ROS) levels in infertile patients with varicocele, and to examine the beneficial effect of varicocelectomy and elucidate predictors of improvement after repair.

PATIENTS SUBJECTS AND METHODS

We prospectively studied 60 patients with varicocele and abnormal semen variables who attended the outpatient clinic complaining of infertility for ≥12 months. In all, 25 patients (41.7%) had bilateral varicoceles and 35 (58.3%) had left varicoceles. The DNA fragmentation index (DFI%, percentage of sperm with denatured nuclei), ROS and total non-enzymatic antioxidant capacity (TAC) were measured. Inguinal varicocelectomy was performed in all patients. At 3-6 months postoperatively, all measurements were repeated. A control group, comprised of 20 normozoospermic fertile men, was included. Regression analysis was used to examine predictors of improvement.

RESULTS

The mean (SD) DFI% in the 60 infertile patients with varicocele was 29.9 (8.3) and 7.56 (2.84)% in the controls; ROS levels were 4.49 (0.9) in patients and 2.62 (0.8) photons/min in controls; and the TAC was 0.97 (0.4) in patients and 1.5 (0.5) mM in controls; with highly significant differences between the patients and controls. The DFI% showed a positive correlation with ROS levels, whilst the total motile sperm count (TMSC) had a significant negative correlation with DFI%, ROS levels and grade of varicocele, whilst there was significant positive correlation with TAC. The grade of varicocele and duration of infertility were related to the presence of higher levels of ROS and increased of DFI%. Postoperatively, improvement (measured as a >50% increase in TMSC) occurred in 40 of 55 (73%) patients available at follow-up, with a significant reduction in the mean (SD) DFI% from 29.49 (8.58) to 18.78 (7.23)%, ROS levels from 4.49 (0.88) to 3.27 (1.3) photons/min (both P < 0.001), and a significant increase in the mean (SD) TAC from 1.01 (0.44) to 2.05 (0.51) mM (P < 0.001). Responders had a shorter infertility duration and lower preoperative DFI% and ROS levels. Regression analysis showed that DFI% is a predictor of improvement after varicocelectomy.

CONCLUSION

SDF was shown to have a negative impact on improvement after varicocelectomy. Hence, DFI% could be recommended as a prognostic test in infertile patients with varicocele to help decision-making as regards the necessity and the anticipated outcome of varicocelectomy in patients with infertility.

Alterations in the proliferative/apoptotic equilibrium in semen of adolescents with varicocele

PURPOSE

To verify if the presence of varicocele (grades II and III) with and without seminal alterations, using the 5^th centile cutoff values in table A1.1 of the World Health Organization (WHO, 2010) manual, alters the seminal plasma levels of proteins DNASE1 (deoxyribonuclease-1) and IGFBP7 (Insulin-like growth factor-binding protein 7), which are related to apoptosis regulation and cell proliferation, respectively, demonstrating that these proteins are important for correct spermatogenesis.

METHODS

This cross sectional study was performed at the Sao Paulo Federal University Paulo between May 2014 and April 2016. A total of 61 male adolescents were included in this study, of which 20 controls without varicocele (C), 22 with varicocele and normal semen analysis (VNS) and 19 with varicocele and altered semen analysis (VAS). Seminal plasma from each patient was used for Western blotting analysis of individual protein levels. Values of each protein were normalized to a testicular housekeeping protein (PARK7-protein deglycase DJ-1).

RESULTS

Levels of IGFBP7 protein are increased in varicocele. Levels of DNASE1 are progressively decreased in varicocele (lower in varicocele and normal semen analysis, lowest in varicocele and altered semen analysis) when compared to adolescents without varicocele. DNASE1 levels are positively correlated with sperm concentration and morphology (correlation values of 0.400 and 0.404, respectively; p values of 0.001 and 0.001, respectively).

CONCLUSION

In conclusion, in adolescents, seminal plasma levels of IGFBP7, responsible for proliferative activity, are increased in varicocele grades II and III, and DNASE1, responsible for apoptosis regulation, are lower in varicocele, lowest in varicocele and low semen quality. These proteins demonstrate molecular alterations brought upon by varicocele. Moreover, DNASE1 is capable of discriminating a varicocele that causes alterations to semen quality from one that does not. We propose that the initial response of varicocele is to increase proliferative activity which, if followed by regulation of apoptosis, may lead to the ejaculation of a population of sperm that are in accordance with WHO cutoff values but, in the presence of dysregulated apoptosis, leads to lower sperm concentration and morphology.

Outcome of assisted reproductive technology in men with treated and untreated varicocele: systematic review and meta-analysis

Varicocele affects approximately 35%-40% of men presenting for an infertility evaluation. There is fair evidence indicating that surgical repair of clinical varicocele improves semen parameters, decreases seminal oxidative stress and sperm DNA fragmentation, and increases the chances of natural conception. However, it is unclear whether performing varicocelectomy in men with clinical varicocele prior to assisted reproductive technology (ART) improve treatment outcomes. The objective of this study was to evaluate the role of varicocelectomy on ART pregnancy outcomes in nonazoospermic infertile men with clinical varicocele. An electronic search was performed to collect all evidence that fitted our eligibility criteria using the MEDLINE and EMBASE databases until April 2015. Four retrospective studies were included, all of which involved intracytoplasmic sperm injection (ICSI), and accounted for 870 cycles (438 subjected to ICSI with prior varicocelectomy, and 432 without prior varicocelectomy). There was a significant increase in the clinical pregnancy rates (OR = 1.59, 95% CI: 1.19-2.12, I 2 = 25%) and live birth rates (OR = 2.17, 95% CI: 1.55-3.06, I 2 = 0%) in the varicocelectomy group compared to the group subjected to ICSI without previous varicocelectomy. Our results indicate that performing varicocelectomy in patients with clinical varicocele prior to ICSI is associated with improved pregnancy outcomes.

Acridine Orange and Flow Cytometry: Which Is Better to Measure the Effect of Varicocele on Sperm DNA Integrity?

We evaluated the effect of varicocelectomy on semen parameters and levels of sperm DNA damage in infertile men. A total of 75 infertile men with varicocele and 40 fertile men (controls) were included in this study. Semen analysis and sperm DNA damage expressed as the DNA fragmentation index using acridine orange staining and chromatin condensation test by flow cytometry were assessed before and 6 months after varicocelectomy. The patients were also followed up for 1 year for pregnancy outcome. Semen parameters were significantly lower in varicocele patients compared to controls (P < 0.05). Mean percentages of sperm DNA fragmentation and sperm DNA chromatin condensation in patients were significantly higher than those in controls (P < 0.05). After varicocelectomy, sperm DNA fragmentation improved significantly, whereas sperm chromatin condensation was not significantly changed. In 15 out of 75 varicocele patients, clinical pregnancy was diagnosed; those with positive pregnancy outcome had significant improvement in sperm count, progressive sperm motility, and sperm DNA fragmentation, but there was no significant difference in sperm DNA condensation compared to negative pregnancy outcome patients. We concluded from this study that acridine orange stain is more reliable method than flow cytometry in the evaluation of sperm DNA integrity after varicocelectomy.

Efficacy of Varicocele Repair in Different Age Groups

OBJECTIVE

To compare semen parameters and spouse pregnancy rates after varicocele repair in 2 age groups.

MATERIALS AND METHODS

Mean changes in spermatozoa concentration, motility, and morphology after varicocele repair in 83 patients were compared between patients aged 30 years or younger (group 1) and those older than 30 years (group 2). Spouse pregnancy rates were compared between the 2 age groups.

RESULTS

The mean sperm concentration increased significantly in both groups (P <.05). The percentage of motile sperm increased from 48.2% to 56.6% in group 1 and from 47.2% to 53.2% in group 2 one year after varicocele repair. The increase in motility was statistically significant for both groups (P <.05), but there was no statistically significant difference in the increase in sperm motility between the 2 groups (P = .01). The percentage of sperm with abnormal morphology decreased significantly in both groups 12 months postoperatively (from 62.7% to 59.6% in group 1 and from 61.3% to 58% in group 2; P = .03). However, there was no statistically significant difference in the improvement in sperm morphology between the 2 groups (P >.05). The pregnancy rates in the patients' spouses were 51.1% and 44.7% in groups 1 and 2, respectively. This difference was not statistically significant (P = .9).

CONCLUSION

There was no statistically significant difference in semen parameter improvement and spouse pregnancy rates after varicocelectomy in the 2 age groups.

[Surgery of male infertility: an update]

Surgery for male infertility includes three main areas: varicocele surgery, recanalization of seminal tract, sperm retrieval.Varicocele treatment in infertily is still controversial. Recent scientific evidence appears to demonstrate that in selected cases varicocele treatment is beneficial in improving semen parameters and pregnancy rate. The key for the success of treatment seems to be a correct indication. It is our opinion that varicocele should be treated in presence of abnormal semen parameters, when clinically significant, and in adolescents with atrophy of the affected testis. So far, no specific technique, either surgical, microsurgical or sclerotherapic, can be considered the gold standard. Good results in our hands have been obtained with the microsurgical lymphatic sparing high ligation of internal spermatic vein.Innovations in surgery for seminal tract obstructions include the new tubular invagination techniques for epididimovasostomy, which showed excellent results with a simplified and time-saving microsurgical approach. In distal obstructions, a new transperineal ultrasound-guided approach has been proposed for the diagnostic work-up and treatment. Advantages of this technique and of the TURED must be balanced with those of immediate sperm retrieval for ART.In sperm retrieval, microTESE represents the most important surgical evolution in non-obstructive azoospermia. We have recently proposed a new stepwise approach starting with a minimal equatorial incision for conventional testicular biopsy which is extended to perform microTESE only when no sperm is retrieved. In this way microTESE is offered only to patients who really need it. Another field of innovation is sperm retrieval for ICSI in patients with Klinefelter Syndrome.

Whether sperm deoxyribonucleic acid fragmentation has an effect on pregnancy and miscarriage after in vitro fertilization/intracytoplasmic sperm injection: a systematic review and meta-analysis

OBJECTIVE

To examine whether sperm DNA fragmentation has an effect on pregnancy and miscarriage after IVF and/or intracytoplasmic sperm injection (ICSI).

DESIGN

Systematic review and meta-analysis.

SETTING

University-affiliated teaching hospital.

PATIENT(S)

Infertility patient(s).

INTERVENTION(S)

An exhaustive electronic literature search was conducted on MEDLINE, Google Scholar, and the Cochrane Library, from database inception to October 2013. We included clinical trials that examined the influence of sperm DNA damage on pregnancy and miscarriage of IVF/ICSI.

MAIN OUTCOME MEASURE(S)

The outcomes of interest were pregnancy rate and miscarriage rate.

RESULT(S)

In the analysis of pregnancy, 16 cohort studies (3,106 couples) were included. Of these, 14 studies (2,756 couples, 965 pregnancies) that also mentioned miscarriage were identified in the analysis of miscarriage. Meta-analysis showed that high-level sperm DNA fragmentation has a detrimental effect on outcome of IVF/ICSI, with decreased pregnancy rate and increased miscarriage rate. The stratified analysis by type of procedure (IVF vs. ICSI) indicated that high sperm DNA damage was related to lower pregnancy rates in IVF but not in ICSI cycles, whereas it was associated with higher miscarriage rates in both IVF and ICSI cycles.

CONCLUSION(S)

The results indicate that assays detecting sperm DNA damage should be recommended to those suffering from recurrent failure to achieve pregnancy. Selection of sperm without DNA damage for use may improve the clinical outcome of ART. The data also provide a rationale for conducting further research aimed at evaluating the underlying mechanism(s) responsible for the detrimental effect of high sperm DNA fragmentation and the potential therapy.

Sperm nuclear vacuoles in relation to acrosome reactions and sperm motility

We investigated sperm nuclear vacuolation in relation to acrosome reactions and the maintenance of sperm motility. Thirty male patients who visited our Male Infertility Clinic were enrolled. These patients underwent conventional semen analyses, Acrobeads tests, and high-magnification observation of the sperm head to evaluate the degree of nuclear vacuolation on the Acrobeads test scoring after 24 hours of incubation. The presence of acrosome reactions was evaluated using the Acrobeads test. The spermatozoa were classified into three groups: (I) those bound to MH61-beads, (II) motile spermatozoa that did not bind to MH61-beads, and (III) immotile spermatozoa that did not bind to MH61-beads. The percentage of spermatozoa with large nuclear vacuoles (%LNV) was compared between the three groups. The degree of sperm nuclear vacuolation was evaluated in 17,992 ejaculated spermatozoa. The mean %LNVs were 2.4% in group I, 5.8% in group II, and 9.8% in group III. These values were significantly different from each other (P < 0.001, paired t-test). There were no correlations between the %LNV values and the Acrobeads scores. In conclusion, the degree of sperm nuclear vacuolation was significantly lower in the acrosome-reacted spermatozoa and spermatozoa with maintained motility, and higher in the immotile spermatozoa that did not bind to MH61-beads.

Multiple determinations of sperm DNA fragmentation show that varicocelectomy is not indicated for infertile patients with subclinical varicocele

Varicocele is one of the most common causes of low semen quality, which is reflected in high percentages of sperm cells with fragmented DNA. While varicocelectomy is usually performed to ameliorate a patient's fertility, its impact on sperm DNA integrity in the case of subclinical varicocele is poorly documented. In this study, multiple DNA fragmentation analyses (TUNEL, SCD, and SCSA) were performed on semen samples from sixty infertile patients with varicocele (15 clinical varicoceles, 19 clinical varicoceles after surgical treatment, 16 subclinical varicoceles, and 10 subclinical varicoceles after surgical treatment). TUNEL, SCD, and SCSA assays all showed substantial sperm DNA fragmentation levels that were comparable between subclinical and clinical varicocele patients. Importantly, varicocelectomy did improve sperm quality in patients with clinical varicocele; however, this was not the case in patients with subclinical varicocele. In summary, although infertile patients with clinical and subclinical varicocele have similar sperm DNA quality, varicocelectomy should only be advised for patients with clinical varicocele.

Role of varicocele repair for male infertility in the era of assisted reproductive technologies

Varicocele is an abnormal condition characterized by dilatation of the pampiniform plexus veins draining the testis and is present in 15 % of men. Varicoceles have an adverse effect on spermatogenesis and are the most common cause of male infertility. Approximately 35 % of infertile men and more than 70 % of men with secondary infertility were reported to have varicoceles. Although data on methods of varicocele repair are accumulating, there remains controversy regarding the indications and techniques for varicocele repair. In addition, the role of varicocele repair in this era of assisted reproductive technologies continues to be debated. In this study, we performed a comprehensive PubMed search in order to review the current status of varicocele repair for male infertility. We reviewed English-language studies published from 1992 through 2013. After reviewing the articles, we identified a recent meta-analysis of four randomized controlled trials, which found that varicocele repair for oligozoospermic men was associated with better pregnancy rates as compared with observation. Our review of prospective studies showed that all semen parameters, including sperm concentration, motility, and progressive motility, were significantly improved after varicocele repair. We also summarize the findings of recent studies reporting beneficial effects of varicocele repair, i.e., decreased oxidative stress and sperm DNA fragmentation after varicocele repair and superior cost effectiveness versus in vitro fertilization/intracytoplasmic sperm injection alone, which may be important in the era of assisted reproductive technologies. Varicocele repair is a widespread, well-established procedure that can improve semen parameters in men with infertility. The effect of such treatment on the pregnancy rate is unclear because evidence is limited due to difficulties in recruiting patients for studies. Among the repair techniques, microsurgical repair using a subinguinal approach is potentially the best practice, although this procedure requires training in microsurgery. All these topics require further research in studies with sufficient patient enrollment and follow-up.

The office visit

This article summarizes the current office-based evaluation of male infertility and offers speculation, based on current research, on the future evolution of this encounter. A comprehensive history, physical examination, and semen analysis remain paramount to directing the evaluation; however, new advances continue to refine diagnostic and treatment algorithms. Interpretation of the routine semen analysis as well as adjunctive assessments, including reactive oxygen species, DNA fragmentation, and fluorescent in situ hybridization (FISH) are discussed. The analysis of genetic and endocrine abnormalities is reviewed.

Observation of spermatozoa by a high-magnification microscope

Semen analyses are the primary tool for evaluating male infertility, as semen parameters are useful for predicting potential fertility. In the field of assisted reproductive technology (ART), the single best motile spermatozoon should be selected, especially when performing intracytoplasmic sperm injection (ICSI). In this context, the motile sperm organelle morphology examination (MSOME) was developed as a method of assessing the detailed morphology of motile spermatozoa in real time at a magnification of up to 6,300× on a video system. The use of ICSI with MSOME-selected sperm is called intracytoplasmic morphologically selected sperm injection (IMSI). IMSI improves the outcomes of ICSI. MSOME can be also applied to evaluate male infertility. Among MSOME parameters, the presence of sperm nuclear vacuoles is the most important finding. Large sperm nuclear vacuoles (LNV) are related not only to poor ART outcomes, but also to poor semen quality and sperm DNA damage, such as DNA fragmentation and chromatin condensation failure. It has been suggested that sperm head vacuoles are produced at earlier stages of sperm maturation. It is possible that the number of LNV can be decreased by surgical or medical treatment for male infertility. Therefore, the level of LNV has the potential to be used as an alternative parameter of semen quality and a new tool for evaluating the therapeutic effects of treatment in male patients with infertility.

Is thioredoxin reductase involved in the defense against DNA fragmentation in varicocele?

We aimed to investigate the role of thioredoxin reductase (TR) and inducible heat shock protein 70 (iHsp70) and their relationship with sperm quality in varicocele (VAR) patients. Semen samples were obtained from 16 subfertile men diagnosed as VAR and 10 fertile men who applied to the Andrology Laboratory of Istanbul Medical Faculty of Istanbul University. The sperm TR and iHsp 70 expression levels were determined using Western blot analysis. The TR activity of the sperm was assayed spectrophometrically. The sperm quality was evaluated both by conventional sperm analysis and by a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) technique that assayed DNA-fragmented spermatozoa in semen samples. The percentage of TUNEL-positive spermatozoa in the VAR group (16.3%± 5.6%) was higher than that in the fertile group (5.5%± 1.9%). Significant inverse correlations were detected between the percentage of TUNEL-positive cells and both the concentration (r=-0.609; P=0.001) and motility (r=-0.550; P=0.004) of spermatozoa. Both the TR expression and activity were increased significantly in the VAR group (U=22.0; P=0.001 and U=33.5; P=0.012, respectively) as analyzed using the Mann-Whitney U Wilcoxon rank sum W test. Furthermore, significant positive correlations were found between TR expression and activity (r=0.406; P=0.040) and between TR expression and the percentage of TUNEL-positive cells (r=0.665; P=0.001). Sperm iHsp70 expression did not differ between the VAR and fertile groups. In conclusion, increased sperm TR expression might be a defense mechanism against apoptosis in the spermatozoa of men with VAR.

Effects of supplement therapy on sperm parameters, protamine content and acrosomal integrity of varicocelectomized subjects

PURPOSE

Surgical repair of varicocele has long been a procedure to correct spermatogenesis. However, the outcome has been reported to be inadequate. We combined varicocelectomy with supplement therapy to evaluate the concurrent effect of these procedures.

METHODS

A prospective randomized controlled study was undertaken to investigate the effects of zinc sulfate, folic acid and zinc sulfate/folic acid on sperm quality, protamine content and acrosomal integrity following surgical repair of varicocele. Male subjects with palpable varicocele were included in the study and randomized into four groups. Subjects received Zinc sulfate, Folic acid, Zinc sulfate/Folic acid or placebo for 6 months. A semen sample was obtained before surgery and 3 and 6 months after surgical repair. Semen samples were evaluated for sperm parameters as well as chromatin content and acrosomal integrity.

RESULTS

Most of the evaluated parameters showed a mild improvement after varicocelectomy in the placebo group. Interestingly, co-administration of Zinc sulfate and folic acid improved most factors significantly. Folic acid administration but not zinc sulfate could increase sperm number. Hence, Zinc sulfate was better than folic acid when change in morphology was assessed, and none of them was significantly effective in sperm motility. In Zinc sulfate and Folic acid groups, protamine content and halo formation rate significantly improved.

CONCLUSIONS

We may conclude that co-administration of zinc and folic acid significantly improved sperm parameters and increased varicocelectomy outcomes. So, medical treatment with compatible drugs after surgery might be advantageous for obtaining acceptable results.

Sperm chromatin structure assay (SCSA®)

The SCSA(®) is the pioneering assay for the detection of damaged sperm DNA and altered proteins in sperm nuclei via flow cytometry of acridine orange (AO) stained sperm. The SCSA(®) is considered to be the most precise and repeatable test providing very unique, dual parameter data (red vs. green fluorescence) on a 1,024 × 1,024 channel scale, not only on DNA fragmentation but also on abnormal sperm characterized by lack of normal exchange of histones to protamines. Raw semen/sperm aliquots or purified sperm can be flash frozen, placed in a box with dry ice and shipped by overnight courier to an experienced SCSA(®) lab. The samples are individually thawed, prepared, and analyzed in ∼10 min. Of significance, data on 5,000 individual sperm are recorded on a 1,024 × 1,024 dot plot of green (native DNA) and red (broken DNA) fluorescence. Repeat measurements have virtually identical dot plot patterns demonstrating that the low pH treatment that opens up the DNA strands at the sites of breaks and staining by acridine orange (AO) are highly precise and repeatable (CVs of 1-3%) and the same between fresh and frozen samples. SCSAsoft(®) software transforms the X-Y data to total DNA stainability versus red/red + green fluoresence (DFI) providing a more accurate determination of % DFI as well as the more sensitive value of standard deviation of DFI (SD DFI) as demonstrated by animal fertility and dose-response toxicology studies. The current established clinical threshold is 25% DFI for placing a man into a statistical probability of the following: (a) longer time to natural pregnancy, (b) low odds of IUI pregnancy, (c) more miscarriages, or (d) no pregnancy. Changes in lifestyle as well as medical intervention can lower the %DFI to increase the probability of natural pregnancy. Couples of men with >25% DFI are counseled to try ICSI and when in the >50% range may consider TESE/ICSI. The SCSA(®) simultaneously determines the % of sperm with high DNA stainability (%HDS) related to retained nuclear histones consistent with immature sperm; high HDS values are predictive of pregnancy failure.The SCSA(®) is considered to be the most technician friendly, time- and cost-efficient, precise and repeatable DNA fragmentation assay, with the most data and the only fragmentation assay with an accepted clinical threshold for placing a man at risk for infertility. SCSA(®) data are more predictive of male factor infertility than classical semen analyses.

The role of varicocele treatment in the management of non-obstructive azoospermia

The literature on male reproductive medicine is continually expanding, especially regarding the diagnosis and treatment of infertility due to non-obstructive azoospermia. The advent of in vitro fertilization with intracytoplasmic sperm injection has dramatically improved the treatment of male infertility due to nonobstructive azoospermia. Assisted reproduction using testicular spermatozoa has become a treatment of hope for men previously thought to be incapable of fathering a child due to testicular failure. In addition, numerous studies on non-obstructive azoospermia have reported that varicocelectomy not only can induce spermatogenesis but can also increase the sperm retrieval rate; however, the value of varicocelectomy in patients with non-obstructive azoospermia still remains controversial. The purpose of this review is to present an overview of the current status of varicocele repair in men with non-obstructive azoospermia.

The effect of sperm DNA fragmentation on miscarriage rates: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between high levels of sperm DNA damage and miscarriage?

SUMMARY ANSWER

Miscarriage rates are positively correlated with sperm DNA damage levels.

WHAT IS KNOWN ALREADY

Most ejaculates contain a subpopulation of sperm with DNA damage, also referred to as DNA fragmentation, in the form of double or single-strand breaks which have been induced in the DNA prior to or following ejaculation. This DNA damage may be particularly elevated in some subfertile men, hence several studies have examined the link between sperm DNA damage levels and conception and miscarriage rates.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis of studies which examined the effect of sperm DNA damage on miscarriage rates was performed. Searches were conducted on MEDLINE, EMBASE and the Cochrane Library without any language restrictions from database inception to January 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used the terms 'DNA damage' or 'DNA fragmentation' combined with 'miscarriage', 'abortion' or 'pregnancy' to generate a set of relevant citations. Data extraction was performed by two reviewers. Study quality was assessed using the Newcastle-Ottawa Scale. Meta-analysis of relative risks of miscarriage was performed with a random effects model. Subgroup analyses were performed by the type of DNA damage test, whether the sperm examined were prepared or from raw semen and for pregnancies resulting from IVF or ICSI treatment.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified 16 cohort studies (2969 couples), 14 of which were prospective. Eight studies used acridine orange-based assays, six the TUNEL assay and two the COMET assay. Meta-analysis showed a significant increase in miscarriage in patients with high DNA damage compared with those with low DNA damage [risk ratio (RR) = 2.16 (1.54, 3.03), P < 0.00001)]. A subgroup analysis showed that the miscarriage association is strongest for the TUNEL assay (RR = 3.94 (2.45, 6.32), P < 0.00001).

LIMITATIONS, REASONS FOR CAUTION

There is some variation in study characteristics, including the use of different assays and different thresholds for DNA damage and the definition of pregnancy loss.

WIDER IMPLICATIONS OF THE FINDINGS

The use of methods which select sperm without DNA damage for use in assisted conception treatment may reduce the risk of miscarriage. This finding indicates that assays detecting DNA damage could be considered in those suffering from recurrent pregnancy loss. Further research is necessary to study the mechanisms of DNA damage and the potential therapeutic effects of antioxidant therapy.

STUDY FUNDING/COMPETING INTEREST(S)

None.

Significant improvement of sperm DNA quality after microsurgical repair of varicocele

Varicocele is currently the most common irregularity identified in males that is associated with impaired spermatogenesis. It primarily presents in the form of decreased sperm count and motility, abnormal morphology, and significantly increased sperm DNA fragmentation. Several studies have shown that surgical repair improves semen parameters and increases the odds of spontaneous pregnancy. However the exact effect of surgical repair treatment remains controversial. Therefore, the aim of our study was to evaluate the effectiveness of microsurgical repair by comparing common semen parameters and sperm DNA fragmentation index (DFI). We evaluated infertile men (n = 19) who underwent microsurgical subinguinal varicocelectomy for treatment of clinical varicocele before and 3 months after surgery. Normozoospermic men (n = 19) were considered as the normal control group. Semen parameters improved significantly after surgery when compared with that before surgery, but still significant differences with the normal control group were observed. In comparison, sperm DNA integrity improved significantly after surgery (percentage DFI decreased from 28.4 ± 15.6% before surgery to 22.4 ± 12.9%, at 3 months post surgery) to similar levels as the normal control group. These results suggest that microsurgical repair may be considered as a treatment option in infertile men with palpable varicocele.