Spermotrend Improves Semen Quality and Infertility in Men with Varicocele —Spermotrend and Male Infertility

Background: Infertility affects 8% - 12% of couples globally, with approximately half of the cases reported in males. Oxidative stress is a common factor increased in the varicocele condition and particularly affects spermatozoa, due to their sensitivity to oxidative signals and testicular hypotrophy. The objective of this clinical trial is to study the effectiveness of Spermotrend in the improvement of sperm parameters in male infertility. Methods: A total of 170 males aged > 18 years with a diagnosis of infertility and varicocele were consecutively enrolled in a Phase II, open-label clinical trial. Spermotrend was administered 1 capsule (450 mg) orally every 8 hours for 6 months and was evaluated through semen analysis at 4 and 6 months of follow-up. Results: The trial results show a significant improvement following the administration of Spermotrend over 6 months in sperm concentration (44.1% at baseline vs. 64.1% at 6 months), sperm survival (28.2% with sperm survival ≥ 2 hours vs.56.5%), normalization of sperm morphology (31.2% vs. 72.9%). Varicocele condition decreased in all patients and, by the end of the study, 55.3% of patients had normal venous flow and dilation. Only 5.9% of the patients showed grade 2 varicocele at the end of the study, while 38.8% showed grade 1 varicocele, with no patients showing grade 3 varicocele. Regarding testicular hypotrophy, 90.6% of the patients completed the study with normalized testicular volume by recovering normal venous flow. Conclusion: A short-term course of Spermotrend may significantly improve sperm parameters associated with male infertility. Clinical Trial Registration: The clinical trial protocol was registered in the international clinical trial registry, ClinicalTrials.gov, with the code: NCT05222841 on 15/06/2021.

Epidemiological and Clinical Aspects of Male Infertility in Patients Consulting at the Urology Department of the Yaounde Central Hospital

Introduction: About 10 to 15% of couples in the world and 20 to 30% in Cameroon consult for infertility problems. Infertility is of male origin in 40% of cases. Our objective was to evaluate the epidemiological and clinical aspects of male infertility in our setting. Methods: This was a cross-sectional and descriptive study, with retrospective data collection from the files of patients received for male infertility, over 5 years and 6 months (from January 1st, 2016 to April 30th, 2021) at the Urology Department of the Yaounde Central Hospital. Phone calls were made to patients with incomplete records for completion following a verbal consent. Data reported on data collection forms were entered into a data entry form designed on CSPro software version 7.2. The database was later exported for descriptive statistics using the IBM SPSS software version 23. Qualitative variables were summarized in frequencies and percentages while quantitative variables were summarized in means with their standard deviations for normally distributed data, or medians and interquartile ranges otherwise. Results: Out of 110 patients whose records were analyzed, the median age was 37.0 years, with an interquartile range of 8.3, with 55.5% in the age group 30 to 39 years. Of these 95 (86.4%) were married, 58 (52.7%) were from the West region, 76 (69.1%) were employed. Past history was dominated by mumps 40 (36.4%), varicocele surgery 25 (22.7%), alcoholism 87 (79.1%) and smoking 15 (13.6%). A disorder of spermatogenesis was found in all our patients: 37 (33.6%) azoospermia, 27 (24.6%) asthenospermia and 26 (23.7%) oligospermia patients. Paraclinical evidence of chlamydia and gonococcal infections were found respectively in 38 (34.5%) and 14 (12.7%) patients, varicocele and testicular dystrophy respectively in 95 (86.4%) and 38 (34.5%) patients. Infertility was primary in 67 (60.9%) patients. Conclusion: Most patients with infertility were in their thirties, had risky social habits and comorbidities. An early start of health promotion activities, comorbidities prevention and early detection of spermogram abnormalities would make it possible to reduce the frequency of male infertility.

Psychosocial Aspects of Male Infertility at the Service of Urology-Andrology of the Hospital of the Sino-Guinean Friendship

Objective: Describe the psychosocial aspects of male infertility at the hospital of the Sino-Guinean Friendship. Patients and method: It is a prospective study of a descriptive type covering a period of 6 months. The study covered 17 patients, all received for a desire to conceive after at least one year of regular sexual intercourse without contraception. The data were collected from patient interviews using a pre-established questionnaire. Results: The average age of the patients was 32.07 years with extremes of 23 years and 42 years. During this study, 64.70% of patients were no longer participating in community ceremonies. The patients’ relationships with their spouse and family deteriorated in 52.94% and 47.06%, respectively. Conversely, relations with the family of origin remained unchanged in 70.59 percent of cases. The reduction in economic activity was by 13 patients (76.48%). Conclusion: Male infertility causes a real psychic earthquake in men with its corollaries of negative feelings. The rather complex moral repercussions of male infertility affect not only the individual, his/her partner, and family, but also economic activity.

The role of small non-coding RNAs(sncRNAs)in male infertility:A scoping review

Objective:To give a brief overview of the field of epigenetics and the potential predictive power that small non-coding RNA(sncRNA)may hold in relation to improving the treatment and diagnosis of male infertility.Methods:PRISMA-ScR was used as the scoping review guideline for this investigation.All article data here have been accessed from MEDLINE–PubMed,Science Direct,EBSCO,Scopus,Sage Journals,and Google Scholar.The terms"small non coding RNA,male,infertility,miRNA,sperm"were used in the search between 2015 and 2023.Results:The study comprised 35 publications in total.Several sncRNAs,miR-155,miR-16,miR-196,miR-525-3p,miR-891 were found to be effective in regulating the mechanism of spermatozoa processing in the infertility of men.sncRNA can be used as a biomarker of male infertility.Conclusions:sncRNAs can act as biomarkers for the diagnosis of reproductive diseases.Actually,by recognizing sncRNAs and their mechanisms,a new way to treat infertile men would be paved.The functional annotation of sncRNAs in spermatogenesis is still in its infancy but has enormous potential.This is despite the fact that many potential sncRNAs have been found to date with the use of cutting-edge technology and publicly accessible sncRNA annotation tools.

Lycopene and male infertility

Excessive amounts of reactive oxygen species （ROS） cause a state of oxidative stress, which result in sperm membrane lipid peroxidation, DNA damage and apoptosis, leading to decreased sperm viability and motility. Elevated levels of ROS are a major cause of idiopathic male factor infertility, which is an increasingly common problem today. Lycopene, the most potent singlet oxygen quencher of all carotenoids, is a possible treatment option for male infertility because of its antioxidant properties. By reacting with and neutralizing free radicals, lycopene could reduce the incidence of oxidative stress and thus, lessen the damage that would otherwise be inflicted on spermatozoa. It is postulated that lycopene may have other beneficial effects via nonoxidative mechanisms in the testis, such as gap junction communication, modulation of gene expression, regulation of the cell cycle and immunoenhancement. Various lycopene supplementation studies conducted on both humans and animals have shown promising results in alleviating male infertility--lipid peroxidation and DNA damage were decreased, while sperm count and viability, and general immunity were increased. Improvement of these parameters indicates a reduction in oxidative stress, and thus the spermatozoa is less vulnerable to oxidative damage, which increases the chances of a normal sperm fertilizing the egg. Human trials have reported improvement in sperm parameters and pregnancy rates with supplementation of 4-8 mg of lycopene daily for 3-12 months. However, further detailed and extensive research is still required to determine the dosage and the usefulness of lycopene as a treatment for male infertility.

"Micro-deletions" of the human Y chromosome and their relationship with male infertility

The Y chromosome evolves from an autochromosome and accumulates male-related genes including sex-determining region of Y-chromosome （SRY） and several spermatogenesis-related genes. The human Y chromosome （60 Mb long） is largely composed of repetitive sequences that give it a heterochromatic appearance, and it consists of pseudoautosomal, euchromatic, and heterochromatic regions. Located on the two extremities of the Y chromosome, pseudoautosomal regions 1 and 2 （PAR1 and PAR2, 2.6 Mb and 320 bp long, respectively） are homologs with the termini of the X chromosome. The euchromatic region and some of the repeat-rich heterochromatic parts of the Y chromosome are called ＂male-specific Y＂ （MSY）, which occupy more than 95% of the whole Y chromosome. After evolution, the Y chromosome becomes the smallest in size with the least number of genes but with the most number of copies of genes that are mostly spermatogenesis-related. The Y chromosome is characterized by highly repetitive sequences （including direct repeats, inverted repeats, and palindromes） and high polymorphism. Several gene rearrangements on the Y chromosome occur during evolution owing to its specific gene structure. The consequences of such rearrangements are not only loss but also gain of specific genes. One hundred and fifty three haplotypes have been discovered in the human Y chromosome. The structure of the Y chromosome in the GenBank belongs to haplotype R1. There are 220 genes （104 coding genes, 111 pseudogenes, and 5 other uncategorized genes） according to the most recent count. The 104 coding genes encode a total of about 48 proteins/protein families （including putative proteins/protein families）. Among them, 16 gene products have been discovered in the azoospermia factor region （AZF） and are related to spermatogenesis. It has been discovered that one subset of gene rearrangements on the Y chromosome, ＂micro-deletions＂, is a major cause of male infertility in some populations. However, controversies exist about different Y chromosome haplotypes. Six AZFs of the Y chromosome have been discovered including AZFa, AZFb, AZFc, and their combinations AZFbc, AZFabc, and partial AZFc called AZFc/gr/gr. Different deletions in AZF lead to different content spermatogenesis loss from teratozoospermia to infertility in different populations depending on their Y haplotypes. This article describes the structure of the human Y chromosome and investigates the causes of micro-deletions and their relationship with male infertility from the view of chromosome evolution. After analysis of the relationship between AZFc and male infertility, we concluded that spermatogenesis is controlled by a network of genes, which may locate on the Y chromosome, the autochromosomes, or even on the X chromosome. Further investigation of the molecular mechanisms underlying male fertility/infertility will facilitate our knowledge of functional genomics.

Prevalent false positives of azoospermia factor a （AZFa） microdeletions caused by single-nucleotide polymorphism rs72609647 in the sY84 screening of male infertility

Multiplex polymerase chain reaction （PCR） has been widely used to detect Y-chromosome micredeletions, which is one of the major causes of male infertility. Both the European Academy of Andrology （EAA） and the European Molecular Genetics Quality Network （EMQN） have recommended the use of sY84 and sY86 markers for the detection of azoospermia factor a （AZFa） microdeletion during DNA testing for male infertility. In this study, a large-scale analysis of AZF microdeletion in a total of 630 Chinese males, including healthy semen donors （n=200）, infertile males with normal sperm count （n=226） and patients with either nonobstructive azoospermia or severe oligozoospermia （n=204）, was performed. A series of nine sequence-tagged site （STS） markers from the AZF region of the Y chromosome was used to detect microdeletions. All primers were designed based on the recommendations of the National Center for Biotechnology Information. An unusually high incidence （73/630, 11.6%） of sY84-absent but sY86-present genotypes was observed in the AZFa microdeletion screening. Sequencing the sY84-flanking region revealed a total of 73 patients with sY84-absent but sY86-present genotypes have a T-to-G transversion at the fifth base from the 5＇ end of the reverse sY84 primer. These prevalent false positives, which were not only observed in infertile men, but also observed in donors, resulted from a single-nucleotide polymorphism （SNP） named rs72609647 in the targeting sequence of the reverse sY84 primer. Our study suggests that a pre-screening of existence of rs72609647 polymorphism can prevent the frequent false positive results of AZFa microdeletions detection in the infertile Chinese males. Given the SNP rs72609647 was recently found in a deep sequencing of a Chinese individual, the current EAA and EMQN standards may need to be scrutinized among different populations to avoid the potential genetic variations in the primer binding sequences.

Human protamines and the developing spermatid: their structure, function, expression and relationshipwith male infertility

<abstract>During spermiogenesis, the protamine proteins play an integral role in spermatid chromatin compaction. Recent research has focused on many facets of protamine biology, including protamine gene and protein structure/ function relationships, mechanisms of protamine expression regulation and involvement of the protamines in male fertility. In this paper, we review our current understanding of the structure and function of the protamine-1 (P1) and protamine-2 (P2) proteins and genes, the expression and regulation of these genes and the relationship between the protamines and male fertility. In addition, we offer a brief outlook on future investigation into protamine proteins.

Correlation between HPV sperm infection and male infertility

Human papillomavirus （HPV） is one of the most common sexually transmitted diseases which comprises a group of small DNA viruses that infect both cutaneous and mucous squamous epithelia. Liquid bead microarray technology （LBMA） were used to evaluate 24 HPV genotypes in confirmed fertile and infertile males of North China so that the effects of HPV infection on semen parameters and relationship with male infertility could be discussed. A total of 1138 subjects were recruited in this study; 142 were HPV-positive （12.48%）. Among 523 confirmed fertile males, only 35 were HPV-positive （6.70%）, and two of them had multiple infections. Among 615 infertile males, 107 were HPV-positive （17.4%）, and 29 of them had multiple infections. Infertile males had a relatively high HPV infection rate compared with confirmed fertile males. Sperm progressive motility （PR） and the normal morphology rate were significantly decreased in HPV-positive subjects. HPV-45, HPV-52, HPV-18, HPV-59 and HPV-16 infections were more frequently in infertile males. Hence, HPV infection is closely related to male infertility which will decrease sperm PR and morphology. HPV-45, HPV-52, HPV-18, HPV-59 and HPV-16 infection seems to be major risk factors.

Male infertility microsurgical training

Microsurgical training is imperative for urologists and clinical andrologists specializing in male infertility. Success in male infertility microsurgery is heavily dependent on the surgeon＇s microsurgical skills. Laboratory-based practice to enhance microsurgical skills improves the surgeon＇s confidence, and reduces stress and operating time, benefiting both the patient and the surgeon. This review provides guidelines for setting up a microsurgical laboratory to develop and enhance microsurgical skills using synthetic and animal models. The role of emerginE techniaues, such as robotic-assisted microsureerv, is also discussed.

Combined conventional/antioxidant“Astaxanthin”treatment for male infertility:a double blind,randomized trial

Aim： To evaluate the treatment of male infertility with a strong natural antioxidant, in addition to conventional treatment. Methods： Using a double blind, randomized trial design, 30 men with infertility of ≥12 months and female partners with no demonstrable cause of infertility received conventional treatment according to the guidelines of the World Health Organization （WHO）, and either a strong antioxidant Astaxanthin 16 rag/day （AstaCarox, AstaReal AB, Gustavsberg, Sweden） or placebo for 3 months. The effects of treatment on semen parameters, reactive oxygen species （ROS）, zona-free hamster oocyte test, serum hormones including testosterone, luteinizing hormone （LH）, follicle stimulating hormone （FSH） and Inhibin B, and spontaneous or intrauterine insemination （IUI）-induced pregnancies were evaluated. Results： ROS and Inhibin B decreased significantly and sperm linear velocity increased in the Astaxanthin group （n = 11）, but not in the placebo group （n = 19）. The results of the zona-free hamster oocyte test tended to improve in the Astaxanthin group in contrast with the placebo group, though not reaching statistical significance. The total and per cycle pregnancy rates among the placebo cases （10.5 % and 3.6 %） were lower compared with 54.5 % and 23. 1% respectively in the Astaxanthin group （P=0.028; P=0.036）. Conclusion： Although the present study suggests a positive effect of Astaxanthin on sperm parameters and fertility, the results need to be confirmed in a larger trial before recommending Astaxanthin for the complementary treatment of infertile men. （Asian J Androl 2005 Sep; 7： 257-262）

The role of antioxidant therapy in the treatment of male infertility： an overview

In recent years, many studies have focused on the effect of oxidative stress, reactive oxygen species （ROS） and antioxidants on the male eproductive system. Under physiological conditions, sperm produces small amounts of ROS, which are needed for fertilisation, acrosome reaction and capacitation. However, if an increased production of ROS is not associated with a similar increase in scavenging systems, peroxidative damage of the sperm plasma membrane and loss of DNA integrity typically occur, which leads to cell death and reduced fertility. Furthermore, since there is no linear correlation between sperm quality and pregnancy rates, an improvement in semen parameters should not be the sole outcome considered in studies of antioxidant therapies. A definitive conclusion regarding the benefit of these therapies is difficult to obtain, as most of the previous studies lacked control groups, considered different antioxidants in different combinations and doses, or did not evaluate pregnancy rates in previously infertile couples. Even if beneficial effects were reported in a few cases of male infertility, more multicentre, double-blind studies performed with the same criteria are necessarv for an increased understanding of the effects of various antioxidants on fertility,

Vleiotic recombination and male infertility： from basic science to clinical reality？

Infertility is a common problem that affects approximately 15% of the population. Although many advances have been made in the treatment of infertility, the molecular and genetic causes of male infertility remain largely elusive. This review will present a summary of our current knowledge on the genetic origin of male infertility and the key events of male meiosis. It focuses on chromosome synapsis and meiotic recombination and the problems that arise when errors in these processes occur, specifically meiotic arrest and chromosome aneuploidy, the leading cause of pregnancy loss in humans. In addition, meiosis-specific candidate genes will be discussed, including a discussion on why we have been largely unsuccessful at identifying disease-causing mutations in infertile men. Finally clinical applications of sperm aneuploidy screening will be touched upon along with future prospective clinical tests to better characterize male infertility in a move towards personalized medicine.

Male infertility: risk factors in Mongolian men

Aim: To determine the most common risk factors of male infertility in Mongolian men attending an infertility clinic. Methods: A prospective, case-control study was conducted in which 430 men were enrolled. All the men had sought their first infertility evaluation between 1998-2002 in the State Research Center on Maternal Child Health, Ulaanbaatar, Mongolia. They were divided into two groups depending on the results of their semen analysis: 191 with abnormal semen and 239 with normal semen profile. Univariate and multivariate analyses were performed to determine any association between risk factors and semen abnormality. Results: Logistic regression analysis demonstrated that the testicular volume, a history of sexually transmitted infections (STI), epididymitis and testicular damage all have statistically significant associations with semen abnormality, when controlled for multiple risk factors. Adjusted odds ratios of 3.4 for mumps orchitis, 2.3 for other orchitis and 3.9 for testicular injury were found. Gonorrhoea, the most commonly reported STIs in this study, gave an adjusted odds ratio of 1.0 for having one or more sperm abnormality. An adjusted odds ratio for subjects with a history of other STIs was 2.7. However, as a predictor of azoospermia, STIs had very high odds ratio, being 5.6 in patients with gonorrhoea and 7.6 in patients with other STIs. Conclusion: A history of pathology involving testicular damage appeared to have the strongest impact on male infertility in Mongolia. STIs have less impact on semen quality except when complicated by orchitis, epididymitis and vasal obstruction.

Genetic variants in TP53 and MDM2 associated with male infertility in Chinese population

The TP53, a transcriptional regulator and tumor suppressor, is functionally important in spermatogenesis. MDM2 is a key regulator of the p53 pathway and modulates p53 activity. Both proteins have been functionally linked to germ cell apoptosis, which may affect human infertility, but very little is known on how common polymorphisms in these genes may influence germ cell apoptosis and the risk of male infertility. Thus, this study was designed to test whether three previously described polymorphisms 72Arg〉Pro （rs1042522） and the Ex2＋ 19C〉T （rs2287498） in TP53, and the 5＇ untranslated region （5＇ UTR） 309T〉G （rs937283） in MDM2, are associated with idiopathic male infertility in a Chinese population. The three polymorphisms were genotyped using OpenArray assay in a hospital-based case-control study, including 580 infertile patients and 580 fertile controls. Our analyses revealed that TP53 Ex2-1-19C〉T and MDM2 309T〉G polymorphisms are associated with male infertility. Furthermore, we detected a nearly statistically significant additive interaction between TP53 rs2287498 and MDM2 rs937283 for the development of male infertility （Pinteraction--O-055）- In summary, this study found preliminary evidence, demonstrating that genetic variants in genes of the TP53 pathway are risk factors for male infertility.

Folate and vitamin B12 in idiopathic male infertility

Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether idiopathic male infertility is associated with variants in folate, vitamin B12 （B12） and total homocysteine （tHcy）-related genes and measured these metabolites in blood. We conducted a case-control study that included 153 men with idiopathic infertility and 184 fertile male controls recruited at the Fertility Center and Antenatal Care Center, University Hospital, Malmo and Lund, Sweden. Serum folate, red cell folate （RCF）, serum B12, plasma tHcy and semen quality were measured. Subjects were genotyped for 20 common variants in 12 genes related to folate/B12/ homocysteine metabolism. Metabolite concentrations and genotype distributions were compared between cases and controls using linear and logistic regression with adjustment for covariates. The phosphatidylethanolamine N-methyltransferase （PEMT） M 175V and TCblR rs173665 polymorphisms were significantly associated with infertility （P=0.01 and P=0.009, respectively）, but not with semen quality. Among non-users of supplements, infertile men had lower serum folate concentrations than fertile men （12.89 vs. 14.73 nmoll^- 1 P=0.02）, but there were no significant differences in RCF, B 12 or tHcy. Folate, B 12 and tHcy concentrations were not correlated with any semen parameters. This study provides little support for low folate or B12 status in the pathogenesis of idiopathic male infertility. Although additional data are needed to confirm these initial findings, our results suggest that PEMTand TCbIR, genes involved in choline and B12 metabolism, merit further investigation in idiopathic male infertility.

Xenoesterogens and male infertility:myth or reality?

Aim: To evaluate the role of polychlorinated biphenyls (PCBs) as a potential environmental hazard in the deteriora-tion of male fertility. Methods: Fifty-three males were studied. After a thorough case history evaluation and rele-vant clinical and laboratory investigations, PCBs were estimated in the seminal plasma of 21 infertile men with 'Unex-plained Male Factor' and 32 fertile controls. Peak retention times of the eluants were compared with those of the com-mercially available standard PCB Mix, and the results confirmed spectrophotometrically. Seminal PCB concentrafonswere compared between i) fertile and infertile men and ii) men from different areas and diets. The relationship betweenPCB concentrations and measures of sperm quality such as the total motile sperm count, was assessed. Results:PCBs were detected in seminal plasma of infertile men but absent from controls. Sperm quantity and quality were sig-nificantly lower in infertile men compared to controls. The highest average PCB concentrations were found in fish-eat-ing urban dwellers, and followed in succession by fish-eating rural dwellers, non fish-eating urban dwellers and nonfish-eating mral dwellers. The total motile sperm counts were inversely proportional to the PCB concentrations and weresignificantly lower than those of the respective controls. Conclusion: PCBs may be instrumental in the deteriorationof sperm quantity and quality, a contaminated fish diet being the main source of exposure.(Asian J Androl 2000 Dec; 2: 263-269 )

CAG-repeat variant in the polymerase γ gene and male infertility in the Chinese population： a meta-analysis

Several studies have reported a relationship between the length of the CAG-repeat in the polymerase y （POLG） gene and male infertility. However, other studies have not reproduced this result. In our study, the POLG-CAG-repeat length was analyzed in 535 healthy individuals from six Chinese Han populations living in different provinces. The frequencies of IO-CAG alleles and genotypes were high （97.38 and 94.13%, respectively）, with no significant difference among the six Chinese Han populations. Furthermore, we determined the distribution of the POLG-CAG-repeat in 150 infertile men and 126 fertile men. Our study suggested that the distributions of POLG-CAG-repeat alleles and genotypes were not significantly different between infertile （95.67 and 92.67%, respectively） and fertile men （97.22 and 94.44%, respectively）. In a subsequent meta-analysis, combining our data with data from previous studies, a comparison of the CAG-repeat alleles in fertile versus infertile men showed no obvious risk for male infertility associated with any particular allele （pooled odds ratio （0R）=0.94; 95% confidence interval （CI）： 0.60-1.48）. The significance level was not attained with any of the following genetic models： homozygote comparison （not lO/not 10 versus 10110： OR= 1.34; 95% Ch 0.66-2.72）, heterozygote comparison （lO/not 10 versus 10/10： OR= 1.04; 95% Ch 0.78-1.38）, dominant model comparison （not lO/not 10＋ 101 not 10 versus 10110. OR= 1.08; 95% Ch 0.79-1.47） and recessive genetic comparison （not lO/not 10 versus lO/not 10＋ 10/10- OR= 1.31; 95% Ch 0.68-2.55）. In conclusion, there is no significant difference of the frequencies of POLG-CAG-repeat variants among six Chinese Han populations, and this polymorphism may not be associated with Chinese male infertility. On the basis of a meta-analysis, there is no obvious association between CAG-repeat variants of the POLG gene and male infertility.

Association between MTHFR A1298C Polymorphism and Male Infertility：A Meta-analysis

There have been several epidemiological studies evaluating the potential association between the methylenetetrahydrofolate reductase（MTHFR） A1298 C polymorphism and the risk of male infertility.However,the results obtained were inconsistent.Therefore,we performed a meta-analysis to further examine the association between the MTHFR A1298 C polymorphism and male infertility.A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to January 15 th,2016.A total of 20 studies with 4293 cases and 4507 controls were included.An odds ratio（OR） and a 95% confidence interval（95% CI） were calculated to assess the strength of the association.A cumulative meta-analysis,sensitivity analysis and assessment of the publication bias were also performed in this study.The results showed that in the overall analysis,the association between the MTHFR A1298 C polymorphism and male infertility was not significant.A stratified analysis by ethnicity revealed a significant increase in the risk of male infertility in the Asian population with the MTHFR A1298 C polymorphism（especially in the heterozygote model：OR=1.20,95% CI=1.01–1.44,P=0.994;the dominant model：OR=1.23,95% CI=1.04–1.45,P=0.996;and the allele model：OR=1.20,95% CI=1.04–1.39,P=0.985） but not in the Caucasian population.In the stratified analyses,no significant association was observed between the different types of male infertility.This meta-analysis suggests the MTHFR A1298 C polymorphism may be a potential risk factor for male infertility,especially in the Asian population.

A case-control study of risk factors for male infertility in Nigeria

Aim： To evaluate the association between selected potential socio-demographic and behavioral risk factors and infertility in Nigerian men. Methods： There were two groups in this study. One group consisted of 150 men with proven male infertility, and the other consisted of 150 fertile men with normal semen parameters. Both were matched for age, place of residence and key socio-demographic variables. They were compared for sexual history, past medical and surgical history, past exposures to sexually transmitted infections and treatment, past and current use of drugs as well as smoking and alcohol intake history. Results： Infertile men were significantly more likely than fertile men to report having experienced penile discharge, painful micturition and genital ulcers, less likely to seek treatment for these symptoms and more likely to seek treatment with informal sector providers. Multivariate analysis showed that male infertility was significantly associated with bacteria in semen cultures, self-reporting of previous use of traditional medications and moderate to heavy alcohol intake, but not with smoking and occupational types. Conclusion： Infertility is associated with various proxies of sexually transmitted infections （STIs） and poor healthcare-seeking behavior for STIs in Nigerian men.