Critical Appraisal of World Health Organization's New Reference Values for Human Semen Characteristics and Effect on Diagnosis and Treatment of Subfertile Men

Decline in semen quality among infertile men in Brazil during the past 10 years

PURPOSE

To investigate whether the semen quality of men undergoing conventional semen analysis is deteriorating over time.

MATERIALS AND METHODS

We analyzed and compared the sperm count, motility and morphology of 2300 semen samples provided by males undergoing conventional seminal analysis, from years 2000 to 2002 and 2010 to 2012. The incidences of severe oligozoospermia and azoospermia over time were also compared.

RESULTS

A total of 764 sperm samples were analyzed in 2000-2002 and 1536 in 2010-2012. Over time, the mean sperm concentration/ml decreased significantly from 61.7 million in 2000-2002 to 26.7 million in 2010-2012 (R2 = 11.4%, p < 0.001), the total sperm concentration decreased significantly from 183.0 million to 82.8 million (R2 = 11.3%, p < 0.001), and the percentage of normal forms decreased significantly from 4.6% to 2.7% (R2 = 9.8%, p < 0.001). The incidence of severe oligozoospermia significantly increased from 15.7% to 30.3% (OR: 1.09, p < 0.001) and the incidence of azoospermia increased from 4.9% to 8.5% (OR: 1.06, p = 0.001).

CONCLUSIONS

This study demonstrated a significant time-related decline in semen quality of infertile patients. This finding might have implications on fertility and emphasizes the need for further studies addressing subject's life-style in order to find and reduce the causative agents. Future prospective and multicenter studies including representative samples of the general population are needed to confirm whether semen quality is really declining.

Usefulness of 2010 world health organization reference values for determining indications for varicocelectomy

OBJECTIVE

To investigate the impact of 2010 World Health Organization (WHO) reference values in patients who underwent microsurgical varicocelectomy.

METHODS

This retrospective cohort study included 206 men who underwent microsurgical varicocelectomy for a clinical varicocele with at least 1 abnormal semen parameter according to the 1999 WHO criteria. The preoperative semen analysis findings were reclassified according to the 2010 WHO criteria, and an improved seminal result after varicocelectomy was defined as a ≥20% increase in sperm count or motility.

RESULTS

Semen results of 114 men (55.3%) were reclassified as being above the reference values according to the 2010 WHO criteria. Among those with below reference values, 79.3% and 34.8% showed improved sperm counts and motility, respectively. However, in patients whose semen results converted to normal, 47.4% and 20.2% showed improved sperm counts and motility, respectively. Among those whose semen results were normal on the 2010 criteria, 58.8% showed improved sperm count or motility after microsurgical varicocelectomy.

CONCLUSION

More than half of the patients whose semen results converted to normal on the 2010 WHO criteria showed improved seminal results after microsurgical varicocelectomy. It is necessary to reconsider the 2010 WHO criteria when determining the surgical indication for microsurgical varicocelectomy.

A unique view on male infertility around the globe

BACKGROUND

Infertility affects an estimated 15% of couples globally, amounting to 48.5 million couples. Males are found to be solely responsible for 20-30% of infertility cases and contribute to 50% of cases overall. However, this number does not accurately represent all regions of the world. Indeed, on a global level, there is a lack of accurate statistics on rates of male infertility. Our report examines major regions of the world and reports rates of male infertility based on data on female infertility.

METHODS

Our search consisted of systematic reviews, meta-analyses, and population-based studies by searching the terms "epidemiology, male infertility, and prevalence." We identified 16 articles for detailed study. We typically used the assumption that 50% of all cases of infertility are due to female factors alone, 20-30% are due to male factors alone, and the remaining 20-30% are due to a combination of male and female factors. Therefore, in regions of the world where male factor or rates of male infertility were not reported, we used this assumption to calculate general rates of male factor infertility.

RESULTS

Our calculated data showed that the distribution of infertility due to male factor ranged from 20% to 70% and that the percentage of infertile men ranged from 2·5% to 12%. Infertility rates were highest in Africa and Central/Eastern Europe. Additionally, according to a variety of sources, rates of male infertility in North America, Australia, and Central and Eastern Europe varied from 4 5-6%, 9%, and 8-12%, respectively.

CONCLUSION

This study demonstrates a novel and unique way to calculate the distribution of male infertility around the world. According to our results, at least 30 million men worldwide are infertile with the highest rates in Africa and Eastern Europe. Results indicate further research is needed regarding etiology and treatment, reduce stigma & cultural barriers, and establish a more precise calculation.

Effects of increased paternal age on sperm quality, reproductive outcome and associated epigenetic risks to offspring

Over the last decade, there has been a significant increase in average paternal age when the first child is conceived, either due to increased life expectancy, widespread use of contraception, late marriages and other factors. While the effect of maternal ageing on fertilization and reproduction is well known and several studies have shown that women over 35 years have a higher risk of infertility, pregnancy complications, spontaneous abortion, congenital anomalies, and perinatal complications. The effect of paternal age on semen quality and reproductive function is controversial for several reasons. First, there is no universal definition for advanced paternal ageing. Secondly, the literature is full of studies with conflicting results, especially for the most common parameters tested. Advancing paternal age also has been associated with increased risk of genetic disease. Our exhaustive literature review has demonstrated negative effects on sperm quality and testicular functions with increasing paternal age. Epigenetics changes, DNA mutations along with chromosomal aneuploidies have been associated with increasing paternal age. In addition to increased risk of male infertility, paternal age has also been demonstrated to impact reproductive and fertility outcomes including a decrease in IVF/ICSI success rate and increasing rate of preterm birth. Increasing paternal age has shown to increase the incidence of different types of disorders like autism, schizophrenia, bipolar disorders, and childhood leukemia in the progeny. It is thereby essential to educate the infertile couples on the disturbing links between increased paternal age and rising disorders in their offspring, to better counsel them during their reproductive years.

Engaging practicing gynecologists in the management of infertile men

In the modern era, contemporary management of male infertility has undergone groundbreaking changes with the introduction of new concepts, advanced testing, and therapeutic interventions. As practicing gynecologists are often the first physicians who encounter an infertile couple, it is essential that these clinicians are continuously updated about the new pearls and pitfalls of male infertility management. Semen analysis is commonly ordered by gynecologists. In 2010, the WHO released new cutoff reference values for the semen parameters adopting novel methodology, which has incited much debate. Reference values have been lowered in comparison with previous standards, with a direct clinical implication in decision-making strategies. Specialized sperm-function tests, such as sperm oxidative stress and sperm chromatin integrity assessments, became clinically available, thus offering an opportunity to better understand sperm dysfunctions concealed during routine semen analysis. Furthermore, the initial counseling of azoospermic men by an andrologically well educated gynecologist may alleviate the misconception and distress surrounding the false belief of sterility, and will clarify the available options of percutaneous and microsurgical sperm-retrieval techniques and assisted conception outcome. Regarding varicocele, which is commonly seen in infertile males, it is now clear that the best treatment option for infertile men with clinical varicocele is the microsurgical vein ligation. Natural conception is significantly improved after varicocelectomy, and recent data suggest that such treatment optimizes reproductive outcome of couples undergoing ICSI or micro-TESE sperm retrieval. Lastly, new therapeutic interventions, including oral antioxidant therapy and lifestyle modifications, have gained increasing attention, as they aid in alleviating male infertility.

Total motile sperm count: a better indicator for the severity of male factor infertility than the WHO sperm classification system

STUDY QUESTION

Does the prewash total motile sperm count (TMSC) have a better predictive value for spontaneous ongoing pregnancy (SOP) than the World Health Organization (WHO) classification system?

SUMMARY ANSWER

The prewash TMSC shows a better correlation with the spontaneous ongoing pregnancy rate (SOPR) than the WHO 2010 classification system.

WHAT IS KNOWN ALREADY

According to the WHO classification system, an abnormal semen analysis can be diagnosed as oligozoospermia, astenozoospermia, teratozoospermia or combinations of these and azoospermia. This classification is based on the fifth percentile cut-off values of a cohort of 1953 men with proven fertility. Although this classification suggests accuracy, the relevance for the prognosis of an infertile couple and the choice of treatment is questionable. The TMSC is obtained by multiplying the sample volume by the density and the percentage of A and B motility spermatozoa.

STUDY DESIGN, SIZE, DURATION

We analyzed data from a longitudinal cohort study among unselected infertile couples who were referred to three Dutch hospitals between January 2002 and December 2006. Of the total cohort of 2476 infertile couples, only the couples with either male infertility as a single diagnosis or unexplained infertility were included (n = 1177) with a follow-up period of 3 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In all couples a semen analysis was performed. Based on the best semen analysis if more tests were performed, couples were grouped according to the WHO classification system and the TMSC range, as described in the Dutch national guidelines for male infertility. The primary outcome measure was the SOPR, which occurred before, during or after treatments, including expectant management, intrauterine insemination, in vitro fertilization or intracytoplasmic sperm injection. After adjustment for the confounding factors (female and male age, duration and type of infertility and result of the postcoital test) the odd ratios (ORs) for risk of SOP for each WHO and TMSC group were calculated. The couples with unexplained infertility were used as reference.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 514 couples did and 663 couples did not achieve a SOP. All WHO groups have a lower SOPR compared with the unexplained group (ORs varying from 0.136 to 0.397). Comparing the couples within the abnormal WHO groups, there are no significant differences in SOPR, except when oligoasthenoteratozoospermia is compared with asthenozoospermia [OR 0.501 (95% CI 0.311-0.809)] and teratozoospermia [OR 0.499 (95% CI: 0.252-0.988)], and oligoasthenozoospermia is compared with asthenozoospermia [OR 0.572 (95% CI: 0.373-0.877)]. All TMSC groups have a significantly lower SOPR compared with the unexplained group (ORs varying from 0.171 to 0.461). Couples with a TMSC of <1 × 10(6) and 1-5 × 10(6) have significantly lower SOPR compared with couples with a TMSC of 5-10 × 10(6) [respectively, OR 0.371 (95% CI: 0.215-0.64) and OR 0.505 (95% CI: 0.307-0.832)].

LIMITATIONS, REASON FOR CAUTION

To include all SOPs during the follow-up period of 3 years, couples were not censured at the start of treatment.

WIDER IMPLICATIONS OF THE FINDINGS

Roughly, three prognostic groups can be discerned: couples with a TMSC <5, couples with a TMSC between 5 and 20 and couples with a TMSC of more than 20 × 10(6) spermatozoa. We suggest using TMSC as the method of choice to express severity of male infertility.

STUDY FUNDING/COMPETING INTERESTS

None.

Pregnancy rates with intrauterine insemination: comparing 1999 and 2010 World Health Organization semen analysis norms

Over the past 30 years, The World Health Organization has serially measured norms for human sperm. In this study, 1999 and 2010 semen analysis norms as predictors of pregnancy were compared during intrauterine insemination (IUI). A retrospective cohort study was conducted using data collected from the Stanford Fertility Center, between 2005 and 2007, with 981 couples undergoing 2231 IUI cycles. Collected semen was categorized according to total motile sperm counts (TMSC): 'normal (N.) 1999 TMSC', 'abnormal (AbN.) 1999/N. 2010 TMSC', or 'AbN. 2010 TMSC'. Sample comparison was also based on individual semen parameters: 'N. 1999 WHO', 'AbN. 1999/N. 2010 WHO', or 'AbN. 2010 WHO'. Pregnancy (defined by beta-HCG concentration) rates were calculated. Data were compared using correlation coefficients, t-tests and chi-squared tests, with and without adjusting for confounders. Pregnancy rate comparison based on TMSC ('N. 1999 TMSC', 'AbN. 1999/N. 2010 TMSC' and 'AbN. 2010 TMSC') showed a negative correlation (r = -0.41, P = 0.05). Pregnancy rate did not differ when comparisons were based on the presence of abnormal parameters, even when controlling for confounders. Therefore, TMSC based on the 1999 parameters shows best correlation with pregnancy rate for IUI; updating these norms in 2010 has little clinical implication in infertile populations.

Is varicocelectomy beneficial in men previously deemed subfertile but with normal semen parameters based on the new guidelines? A retrospective study

OBJECTIVE

To determine whether using the 2010 World Health Organization (WHO) semen parameter reference values to select varicocelectomy candidates may exclude infertile men who can potentially benefit from this treatment. With the application of the 2010 WHO semen parameter thresholds, some men previously considered to have abnormal semen parameters would now be considered normozoospermic.

METHODS

We conducted a retrospective review of infertile men with varicocele and identified those with abnormal semen parameters according to WHO 1992 or 1999 standards but normozoospermic by WHO 2010 standards. We compared outcomes (semen parameters and spontaneous pregnancy) of couples undergoing varicocelectomy with those choosing observation.

RESULTS

We identified 445 infertile men with varicocele and abnormal semen parameters by WHO 1992 or 1999 standards. Fifty-six of 445 men (13%) were normozoospermic by WHO 2010. Thirty-two of 56 (57%) of these normozoospermic men elected to have varicocelectomy, and 24 of 56 men (43%) choosing observation. In these normozoospermic men (by WHO 2010), varicocelectomy was associated with a significant increase in sperm concentration (50 ± 35 × 10(6)/mL [postsurgery] vs. 32 ± 23 × 10(6)/mL [presurgery]; P = .003). Although not statistically significant, the clinical pregnancy rate was higher in the varicocelectomy group compared with the observation group (52% vs. 38%; P = .37).

CONCLUSION

Varicocelectomy may be beneficial in those men with clinical varicocele and abnormal semen parameters by WHO 1992 or 1999 standards but now normozoospermic by WHO 2010 standards. Applying the 2010 WHO semen parameter reference values into practice may result in missed opportunities to correct treatable causes of male infertility.

A clinical appraisal of the genetic basis in unexplained male infertility

Unexplained male infertility (UMI), the inability to reproduce despite having a normal sexual history, physical exam and semen analysis, can have a genetic origin. Currently, few diagnostic tools are available for detecting such genetic abnormalities. Karyotyping and fluorescence in situ hybridization (FISH) are respectively used for chromosomal alterations in somatic cells and sperm aneuploidy assessment. Gene sequencing and mutational analysis have been introduced for identifying specific mutations and polymorphisms. Other approaches to the molecular evaluation of spermatozoa are under investigation, including array comparative genomic hybridization and whole-genome sequencing and non-coding ribonucleic acid arrays. Although treating cytogenetic abnormalities and genetic aberrations is still out of reach, the integration of these novel techniques may unravel hidden genetic defects in UMI. Finally, a deeper understanding of the sperm epigenome might allow the development of therapies based on epigenome modifications. This review focuses on the genetic basis of UMI and highlights the current and future methods for the evaluation of genetic defects as they relate to UMI. Review of the literature was carried out using ScienceDirect, OVID, PubMed and MedLine search engines.

A translational medicine appraisal of specialized andrology testing in unexplained male infertility

The diagnostic and prognostic validity of sperm function biomarkers is particularly relevant for males with unexplained infertility in which routine semen analysis fails to detect subcellular sperm dysfunctions. In this general review, we examine the role and significance of specialized andrology laboratory tests from past to present and provide a glance toward the future. We concluded that the assessment of sperm DNA damage and oxidative stress provide a relatively independent measure of fertility that yields diagnostic and prognostic information complementary to, but distinct and more significant than, standard sperm parameters. Since none of the available methods for such testing have been fully translated, further research is necessary to evaluate their cost-effectiveness when applied in large scale to daily medical practice. Application of translational medicine concepts would also be useful to accelerate the clinical application of recent discoveries in the fields of genomics, proteomics and metabolomics.

Sperm deoxyribonucleic acid damage in normozoospermic men is related to age and sperm progressive motility

OBJECTIVE

To evaluate sperm DNA fragmentation in normozoospermic male partners of couples undergoing infertility evaluation.

DESIGN

Retrospective cohort study.

SETTING

Clinical andrology laboratory.

PATIENT(S)

A total of 1,974 consecutive normozoospermic men selected from a larger cohort of 4,345 consecutive, nonazoospermic men presenting for infertility evaluation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical parameters, conventional semen parameters, and sperm DNA fragmentation assessed by flow cytometry-based TUNEL assay and reported as percent sperm DNA fragmentation (%SDF).

RESULT(S)

The mean (± SD) %SDF and the proportion of men with high %SDF (>30%) were significantly lower in the normozoospermic compared with the entire cohort of 4,345 evaluable infertile men (17.6% ± 10.1% vs. 20.7% ± 12.4% and 11% vs. 20%, respectively). In the group of 1,974 normozoospermic men, %SDF was positively correlated with paternal age (r = 0.17) and inversely correlated with progressive motility (r = -0.26). In the subset of normozoospermic men with sperm parameters above the 50th percentile (≥ 73 × 10(6) sperm/mL, ≥ 55% progressive motility, and ≥ 14% normal forms, World Health Organization 2010 guidelines), 5% (4 of 83) had elevated %SDF (>30%).

CONCLUSION(S)

In this large cohort of normozoospermic men presenting for infertility evaluation, DNA fragmentation level is related to sperm motility and paternal age, and 11% of these men have high levels of sperm DNA fragmentation. Furthermore, the data indicate that a nonnegligible proportion (5%) of normozoospermic men with high-normal sperm parameters may also have significant sperm DNA fragmentation.

Which isolated sperm abnormality is most related to sperm DNA damage in men presenting for infertility evaluation

BACKGROUND

Sperm DNA damage is common in infertile men and is associated with poor semen parameters but the impact of an isolated sperm abnormality on sperm DNA damage has not been studied.

OBJECTIVE

To evaluate sperm DNA damage in a large cohort of infertile men with isolated sperm defects.

DESIGN, SETTING AND PARTICIPANTS

Retrospective study of 1084 consecutive, non-azoospermic infertile men with an isolated sperm defect: isolated oligozoospermia (iOligo), isolated asthenozoospermia (iAstheno) or isolated teratozoospermia (iTerato).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We examined and compared clinical parameters, conventional semen parameters and %sperm DNA fragmentation (%SDF, assessed by flow cytometry-based Terminal deoxynucleotidyl transferase-mediated dUTP Nick End-Labeling assay) in the three groups of men.

RESULTS AND LIMITATIONS

The mean (±SD) %SDF was significantly higher in the iAstheno compared to the iOligo and iTerato groups (25.0 ± 14.0 vs. 19.2 ± 11.6 and 20.7 ± 12.1 %, respectively, P < 0.0001). Similarly, the proportion of men with high %SDF (>30 %) was significantly higher in the iAstheno compared to the iOligo and iTerato groups (31 % vs. 18 % and 19 %, respectively, P < 0.0001). In the group of 713 men with iAstheno, %SDF was positively correlated with paternal age (r = 0.20, P < 0.0001) and inversely correlated with %progressive motility (r = -0.18, P < 0.0001). In the subset of 218 men with iTerato, %SDF was also positively correlated with paternal age (r = 0.15, P = 0.018) and inversely correlated with %progressive motility (r = -0.26, P = 0.0001).

CONCLUSIONS

In this large cohort of infertile men with isolated sperm abnormalities, we have found that the sperm DNA fragmentation level is highest in the men with sperm motility defects and that 31 % of these men have high levels of sperm DNA fragmentation. The data indicate that poor motility is the sperm parameter abnormality most closely related to sperm DNA damage.

Shedding light on the controversy surrounding the temporal decline in human sperm counts: a systematic review

We systematically examined the evidence of declining sperm counts and the hypothesis that an increased exposure to environmental pollutants is responsible for such decline. Search engines, including PUBMED, MEDLINE, EMBASE, BIOSIS, and Cochrane library, were used to identify epidemiologic studies published from 1985 to 2013. We concluded that there is no enough evidence to confirm a worldwide decline in sperm counts. Also, there seems to be no scientific truth of a causative role for endocrine disruptors in the temporal decline of sperm production. Such assumptions are based on few meta-analyses and retrospective studies, while other well-conducted researches could not confirm these findings. We acknowledge that difficult-to-control confounding factors in the highly variable nature of semen, selection criteria, and comparability of populations from different time periods in secular-trend studies, the quality of laboratory methods for counting sperm, and apparently geographic variations in semen quality are the main issues that complicate the interpretation of the available evidence. Owing to the importance of this subject and the uncertainties still prevailing, there is a need not only for continuing monitoring of semen quality, reproductive hormones, and xenobiotics, but also for a better definition of fecundity.

New World Health Organization reference values for semen analysis: where do we stand?

Semen analysis is of paramount importance to study potential male fertility, couple's infertility, the effects of gonadotoxic agents on spermatogenesis and as follow-up test during treatment of male infertility. Since 1987, the World Health Organization proposes the standardization of this test and its reference values based on population-based data. The latest version of the World Health Organization guidelines was published in 2010. It introduced a new methodology that produced new references values, which triggered a discussion that lies inconclusive. We revised the original World Health Organization paper focusing on methodological changes and its results, the new references values and their impact on clinical practice.

Should sperm be cryopreserved after spinal cord injury?

In spinal cord injured (SCI) patients, three main factors may cause infertility: erectile dysfunction, ejaculatory dysfunction and impaired semen quality. This letter aims to discuss how we can manage SCI patients’ fertility in accordance with patient-centred care. For such SCI patients aged 20 to 40, having children represents hope for the future. Furthermore, it is a way to rebuild a life after the spinal injury and must be seen as an important part of the rehabilitation program. We suggest that sperm cryopreservation may contribute to patient-centred care management of SCI patients’ fertility, although there is no scientific evidence that cryopreservation will improve fertility outcome after SCI. Indeed, sperm cryopreservation is an affordable and simple technique in specialised centres with trained staff. Here, a protocol to manage SCI patients’ fertility is discussed: we propose PVS for sperm banking to all SCI patients after the phase of spinal shock during the rehabilitation program. If live sperm are retrieved, they are frozen and stored; however, if no live sperm are retrieved, electroejaculation and/or surgical sperm extraction are proposed only for patients who desire biological fatherhood. Prospective studies on the evolution of semen parameters, ejaculatory dysfunction, post-infectious obstructions and spermatogenesis impairment in chronic SCI patients are urgently needed to provide robust data for the evidence-based management of SCI patients’ fertility. Even if use rates are expected to be low, sperm banking may be a simple and affordable preventative measure for selected male SCI patients.

Approach to male infertility and induction of spermatogenesis

Male subfertility is common, and it causes significant duress to couples. Although the most common cause of male subfertility is idiopathic failure of spermatogenesis, a significant percentage of male subfertility is medically treatable. Compared to reproductive specialists, endocrinologists may see a population of men that have a higher prevalence of treatable causes of subfertility including sexual disorders, endocrinopathies, obesity, drugs, and ejaculatory dysfunction. Seminal fluid analysis is the most important diagnostic study, and at least 2 samples should be analyzed. All patients with sperm concentrations < 10 million/mL due to idiopathic spermatogenic defects should be referred for genetic counseling and karyotyping; most experts also recommend that these patients be tested for Y chromosomal microdeletions. For most men with low sperm concentrations due to gonadotropin deficiency, gonadotropin therapy effectively increases spermatogenesis. The endocrinologist must recognize when to use medical therapy to stimulate spermatogenesis and when to refer for consideration of assisted reproductive technology.

The impact of sperm DNA damage in assisted conception and beyond: recent advances in diagnosis and treatment

Sperm DNA damage is a useful biomarker for male infertility diagnosis and prediction of assisted reproduction outcomes. It is associated with reduced fertilization rates, embryo quality and pregnancy rates, and higher rates of spontaneous miscarriage and childhood diseases. This review provides a synopsis of the most recent studies from each of the authors, all of whom have major track records in the field of sperm DNA damage in the clinical setting. It explores current laboratory tests and the accumulating body of knowledge concerning the relationship between sperm DNA damage and clinical outcomes. The paper proceeds to discuss the strengths, weaknesses and clinical applicability of current sperm DNA tests. Next, the biological significance of DNA damage in the male germ line is considered. Finally, as sperm DNA damage is often the result of oxidative stress in the male reproductive tract, the potential contribution of antioxidant therapy in the clinical management of this condition is discussed. DNA damage in human spermatozoa is an important attribute of semen quality. It should be part of the clinical work up and properly controlled trials addressing the effectiveness of antioxidant therapy should be undertaken as a matter of urgency. Sperm DNA damage is a useful biomarker for male infertility diagnosis and prediction of assisted reproduction outcomes. It is associated with reduced fertilization rates, embryo quality and pregnancy rates, and higher rates of spontaneous miscarriage and childhood diseases. With all of these fertility check points, it shows more promise than conventional semen parameters from a diagnostic perspective. Despite this, few infertility clinics use it routinely. This review provides a synopsis of the most recent studies from each of the authors, all of whom have major track records in the field of sperm DNA damage in the clinical setting. It explores current laboratory tests and the accumulating body of knowledge concerning the relationship between sperm DNA damage and clinical outcomes. The paper proceeds to discuss the strengths and weaknesses and clinical applicability of current sperm DNA fragmentation tests. Next, the biological significance of DNA damage in the male germ line is considered. Finally, as sperm DNA damage is often the result of increased oxidative stress in the male reproductive tract, the potential contribution of antioxidant therapy in the clinical management of this condition is discussed. As those working in this field of clinical research, we conclude that DNA damage in human spermatozoa is an important attribute of semen quality which should be carefully assessed in the clinical work up of infertile couples and that properly controlled trials addressing the effectiveness of antioxidant therapy should be undertaken as a matter of urgency.

Unexplained male infertility: diagnosis and management

Unexplained male infertility is a diagnosis reserved for men in whom routine semen analyses results are within normal values and physical as well as endocrine abnormalities were ruled out. In addition to erectile problems and coital factors, immunologic causes and sperm dysfunction may contribute to such condition. New etiologies of unexplained male infertility include low level leukocytospermia and mitochondrial DNA polymerase gene polymorphism. Contemporary andrology may reveal cellular and sub-cellular sperm dysfunctions which may explain subfertility in such cases, thus aiding the clinician to direct the further work-up, diagnosis and counseling of the infertile male. The objective of this article is to highlight the concept of unexplained male infertility and focuses on the diagnosis and treatment of this condition in the era of modern andrology and assisted reproductive techniques. Extensive literature review was performed using the search engines: Pubmed, Science-direct, Ovid and Scopus.

Connexin 43 a check-point component of cell proliferation implicated in a wide range of human testis diseases

Gap junction channels link cytoplasms of adjacent cells. Connexins, their constitutive proteins, are essential in cell homeostasis and are implicated in numerous physiological processes. Spermatogenesis is a sophisticated model of germ cell proliferation, differentiation, survival, and apoptosis, in which a connexin isotype, connexin 43, plays a crucial role as evidenced by genomic approaches based on gene deletion. The balance between cell proliferation/differentiation/apoptosis is a prerequisite for maintaining levels of spermatozoa essential for fertility and for limiting anarchic cell proliferation, a major risk of testis tumor. The present review highlights the emerging role of connexins in testis pathogenesis, focusing specifically on two intimately interconnected human testicular diseases (azoospermia with impaired spermatogenesis and testicular germ cell tumors), whose incidence increased during the last decades. This work proposes connexin 43 as a potential cancer diagnostic and prognostic marker, as well as a promising therapeutic target for testicular diseases.

Environmentally induced epigenetic transgenerational inheritance of altered Sertoli cell transcriptome and epigenome: molecular etiology of male infertility

Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset disease, including testis disease and male infertility. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. As previously observed, enhanced spermatogenic cell apoptosis was observed. The Sertoli cells provide the physical and nutritional support for the spermatogenic cells. Over 400 genes were differentially expressed in the F3 generation control versus vinclozolin lineage Sertoli cells. A number of specific cellular pathways were identified to be transgenerationally altered. One of the key metabolic processes affected was pyruvate/lactate production that is directly linked to spermatogenic cell viability. The Sertoli cell epigenome was also altered with over 100 promoter differential DNA methylation regions (DMR) modified. The genomic features and overlap with the sperm DMR were investigated. Observations demonstrate that the transgenerational sperm epigenetic alterations subsequently alters the development of a specific somatic cell (Sertoli cell) epigenome and transcriptome that correlates with adult onset disease (male infertility). The environmentally induced epigenetic transgenerational inheritance of testis disease appears to be a component of the molecular etiology of male infertility.

What every gynecologist should know about male infertility: an update

PURPOSE

Our article reviews the evolving concepts in the field of male infertility for gynecologists and other health professionals involved in the care of men and women experiencing difficulty in having a child. The increased knowledge will help in the better management and treatment of infertile couples.

METHODS

Review of literature through Pubmed, Science Direct, Online Library.

RESULTS

Gynecologists are often the first healthcare providers to assess an infertile couple. Because half of all infertility problems stem from male factors, it is crucial for the gynecologist to remain updated on the main conditions that cause male infertility as well as current diagnostic tools and treatment options, including conventional strategies and assisted reproductive techniques.

CONCLUSIONS

Extraordinary advances have been achieved in the field of male infertility over the past several years and many old concepts are now challenged. Therefore, it is imperative that male infertility physicians should update the gynecologists about the recent advances in the work-up of infertile men in terms of diagnosis and management. Such convention will help improve the standards of care for the infertile couple and enhance the cooperation between male and female reproductive endocrinologists.

A critical appraisal on the role of varicocele in male infertility

Varicocele is a major cause of male infertility, as it may impair spermatogenesis through several distinct physiopathological mechanisms. With the recent advances in biomolecular techniques and the development of novel sperm functional tests, it has been possible to better understand the mechanisms involved in testicular damage provoked by varicocele and, therefore, propose optimized ways to prevent and/or reverse them. Up to now, there is still controversy involving the true benefit of varicocele repair in subfertile men as well as in certain specific situations such as concomitant contralateral subclinical varicocele or associated nonobstructive azoospermia. Also, with the continued development of assisted reproductive technology new issues and questions are emerging regarding the role of varicocelectomy in this context. This paper reviews the most recent data available on the pathogenesis, diagnosis, and management of varicocele with regard to male infertility.