ABSTRACT
Abstract Robotic surgery opened a new era of minimally-invasive procedures, through its improved precision, elimination of tremors, greater degrees of freedom, and other facilitating aspects. The field of robotic microsurgery showed great growth in recent years in particular, since robotics offers a potentially-ideal configuration to perform the sensitive manipulations required in microsurgery. We conducted a systematic review to assess the benefits of robotic surgery and its contributions to microsurgery, comparing it with other surgical techniques used in patients of all age groups. We assessed 25 articles found in the PubMed and Cochrane databases using the terms 'robotic surgery' AND microsurgery, with a filter for studies published in the last five years, and studies conducted in humans and published in English or Portuguese. We concluded that there is plenty of room for robotic surgery in microsurgery, such as in male infertility procedures, neurological microsurgery, ocular and otological surgeries, and transoral, hepatobiliary, microvascular, plastic and reconstructive surgeries.
Resumo A cirurgia robótica abriu uma nova era de procedimentos minimamente invasivos, por meio da sua precisão, da eliminação dos tremores, e dos maiores graus de liberdade e demais aspectos facilitadores. O campo da microcirurgia robótica apresentou grande crescimento nos últimos anos em especial, uma vez que a robótica oferece uma configuração potencialmente ideal para realização das manipulações delicadas exigidas na microcirurgia. Assim, conduzimos uma revisão sistemática com o objetivo de avaliar os benefícios da cirurgia robótica e sua contribuição para a microcirurgia, comparando-a com as demais técnicas cirúrgicas utilizadas em pacientes de todas as faixas etárias. Foram analisados 25 artigos encontrados nas bases de dados PubMed e Cochrane utilizando os descritores robotic surgery AND microsurgery com filtro para os últimos cinco anos, e estudos realizados em humanos e publicados em inglês ou português. Concluímos que existe grande espaço para a cirurgia robótica na microcirurgia, como em procedimentos primários de infertilidade masculina, microcirurgia neurológica, cirurgias oculares e otológicas, cirurgia transoral, hepatobiliar, microvascular, e cirurgia plástica e reconstrutiva.
Subject(s)
Humans , Male , Minimally Invasive Surgical Procedures , Robotic Surgical Procedures , Infertility, Male , MicrosurgeryABSTRACT
Introdução: Diversos fatores podem interferir na infertilidade masculina, tais como o conteúdo de zinco disponível e o excesso de peso. Desta forma, o objetivo deste estudo é investigar a associação entre a fertilidade de espermatozoides, os níveis séricos de zinco e o excesso de peso em homens frequentadores de uma clínica de Urologia de Santa Cruz do Sul/RS. Métodos: Estudo transversal, de caráter exploratório, quantitativo e descritivo, realizado com homens que consultaram em uma clínica de Urologia localizada no município de Santa Cruz do Sul/RS. Foram realizados exames de espermograma, zinco sérico, bem como de avaliação antropométrica para verificar o estado nutricional. A associação entre as variáveis foi testada utilizando a análise de correlação (Pearson ou Spearman), com nível de significância de p<0,05. Resultados: Do total de pacientes avaliados (n=8, idade média de 35,13±8,15 anos), apenas dois indivíduos (25%) apresentaram concentração de espermatozoides menor que a esperada, e nenhum deles apresentou morfologia anormal. Em relação à determinação de zinco sérico, verificou-se associação significativa entre os níveis de zinco e a motilidade progressiva dos espermatozoides (r=0,825; p=0,012), bem como com a motilidade progressiva + não progressiva dos espermatozoides (r=0,730; p=0,040), mas não com os outros marcadores de fertilidade (p>0,05). Dos pacientes avaliados, seis (75%) apresentaram excesso de peso, e o estado nutricional não se associou com os marcadores de fertilidade masculina (p>0,05). Conclusão: Este estudo mostrou uma associação entre a motilidade dos espermatozoides e os níveis séricos de zinco, mas não com o estado nutricional.
Introduction: Many factors can interfere with male fertility, such as available zinc levels and overweight. The aim of this study is thus to investigate the association between sperm fertility, serum zinc levels, and overweight in men who visited a urology clinic in Santa Cruz do Sul, RS. Methods: This is a cross-sectional study with an exploratory, quantitative, and descriptive approach, performed with men seen at a urology clinic in the municipality of Santa Cruz do Sul, RS. We performed sperm count and serum zinc tests, as well as an anthropometric assessment to verify the patients' nutritional status. The association between variables was tested using a correlation analysis (Pearson or Spearman's) with a significance level of p<0.05. Results: Out of all patients evaluated in this study (n=8, mean age of 35.13±8.15 years), only two individuals (25%) presented sperm counts below the expected threshold and none of them presented abnormal sperm morphology. Regarding serum zinc measurements, a significant association was seen between zinc levels and progressive sperm motility (r=0.825; p=0.012), as well as progressive + non-progressive sperm motility (r=0.730; p=0.040), but no association was seen with other markers of fertility (p>0.05). Among the assessed patients, six (75%) were overweight and their nutritional status was not associated with markers of male fertility (p>0.05). Conclusion: This study showed an association of sperm motility with serum zinc levels, but not with the patients' nutritional status.
Subject(s)
Infertility, MaleABSTRACT
ABSTRACT Purpose: Sperm DNA fragmentation (SDF) and seminal oxidative stress are emerging measurable factors in male factor infertility, which interventions could potentially reduce. We evaluated (i) the impact of lifestyle changes combined with oral antioxidant intake on sperm DNA fragmentation index (DFI) and static oxidation-reduction potential (sORP), and (ii) the correlation between DFI and sORP. Materials and Methods: We conducted a prospective study involving 93 infertile males with a history of failed IVF/ICSI. Ten healthy male volunteers served as controls. Semen analysis was carried out according to 2010 WHO manual, whereas seminal sORP was measured using the MiOXSYS platform. SDF was assessed by sperm chromatin structure assay. Participants with DFI >15% underwent a three-month lifestyle intervention program, primarily based on diet and exercise, combined with oral antioxidant therapy using multivitamins, coenzyme Q10, omega-3, and oligo-elements. We assessed changes in semen parameters, DFI, and sORP, and compared DFI results to those of volunteers obtained two weeks apart. Spearman rank correlation tests were computed for sORP and DFI results. Results: Thirty-eight (40.8%) patients had DFI >15%, of whom 31 participated in the intervention program. A significant decrease in median DFI from 25.8% to 18.0% was seen after the intervention (P <0.0001). The mean DFI decrease was 7.2% (95% CI: 4.8-9.5%; P <0.0001), whereas it was 0.42% (95%CI; -4.8 to 5.6%) in volunteers (P <0.00001). No differences were observed in sperm parameters and sORP. Based on paired sORP and DFI data from 86 patients, no correlation was observed between sORP and DFI values (rho=0.03). Conclusion: A 3-month lifestyle intervention program combined with antioxidant therapy reduced DFI in infertile men with elevated SDF and a history of failed IVF/ICSI. A personalized lifestyle and antioxidant intervention could improve fertility of subfertile couples through a reduction in DFI, albeit controlled trials evaluating reproductive outcomes are needed before firm conclusions can be made. Trial registration number and date: clinicaltrials.gov NCT03898752, April 2, 2019.
Subject(s)
Humans , Male , Infertility, Male/drug therapy , Antioxidants/metabolism , Antioxidants/therapeutic use , Spermatozoa , Fertilization in Vitro , Pilot Projects , Prospective Studies , Oxidative Stress , DNA Fragmentation , Life StyleABSTRACT
RESUMEN: La reciente pandemia de la COVID-19 ha sacudido a la sociedad teniendo una importante repercusión en el campo de la salud y de la investigación. Dada su relevancia, se han llevado a cabo estudios sobre los efectos del SARS-CoV-2 en la fisiología humana. En concreto, sobre la posible presencia y transmisión del virus a través del sistema reproductor masculino y su posible efecto en el éxito reproductivo. Conocer si la presencia del virus altera los órganos responsables del desarrollo y maduración de las células de la serie espermatogénica podría revelarnos su implicación en la calidad seminal. Por ello, nos planteamos esta revisión, con el fin de analizar las principales evidencias científicas sobre los efectos del SARS-CoV-2 en la histofisiología del sistema reproductor masculino y sobre la capacidad fecundante de los espermatozoides.
SUMMARY: The recent COVID-19 pandemic has shaken up society, having a significant impact on the field of health and research. Given its relevance, studies have been performed on the effects of SARS-CoV-2 on human physiology. In particular, the possible presence and transmission of the virus through the male reproductive system could affect reproductive success. Knowing if the presence of the virus disrupts the organs responsible for the development and maturation of the cell lines involved in spermatogenesis could reveal its implications in sperm quality. For that reason, we proposed this review, in order to analyze the main scientific evidence on the effects of SARS-CoV-2 on the histophysiology of the male reproductive system and sperm fertilizing capacity.
Subject(s)
Humans , Male , COVID-19 , Genitalia, Male/virology , Infertility, Male/virology , Spermatozoa/virology , DNA Fragmentation , SARS-CoV-2 , Genitalia, Male/physiopathology , Infertility, Male/physiopathologyABSTRACT
Abstract Carbon tetrachloride (CCl4) represents an organic chemical that causes reactive oxygen species derived organ disturbances including male infertility. Melatonin (MLT) is a neurohormone with strong antioxidant capacity, involved in numerous physiological processes. In this study we evaluated the capability of MLT, administered in a single dose of 50 mg/kg, to preserve the testicular tissue function after an acute administration of CCl4 to rats. The disturbance in testicular tissue and the effects of MLT after CCl4 exposure were estimated using biochemical parameters that enabled us to determine the tissue (anti)oxidant status and the intensity of arginine/nitric oxide metabolism. Also, the serum levels of testosterone and the histopathological analysis of tissue gave us a better insight into the occurring changes. A significant diminution in tissue antioxidant defences, arginase activity and serum testosterone levels, followed by the increased production of nitric oxide and extensive lipid and protein oxidative damage, was observed in the CCl4-treated group. The application of MLT after the CCl4 caused changes, clearly visible at both biochemical and histological level, which could be interpreted mainly as a consequence of general antioxidant system stimulation and a radical scavenger. On the other hand, the application of MLT exerted a limited action on the nitric oxide signalling pathway.
Subject(s)
Animals , Male , Rats , Arginine/metabolism , Carbon Tetrachloride/adverse effects , Melatonin/analysis , Single Dose/classification , Infertility, Male , AntioxidantsABSTRACT
Aromatase deficiency (AD) is a rare autosomal recessive genetic disease caused by loss-of-function mutations in aromatase gene (CYP19A1), leading to congenital estrogen deficiency syndrome. Both mothers of AD patients during pregnancy and female AD fetus show virilization, while male patients are usually diagnosed in adulthood due to continued height increase and metabolic abnormalities. In 2019, a patient with AD was admitted in the Second Xiangya Hospital. The patient was a 37-year-old adult male who continued to grow linearly after adulthood. His estradiol was below the measurable line, the follicle-stimulating hormone (FSH) increased, bone age delayed, epiphysis unfused, and the bone mass reduced. CYP19A1 gene detection showed that c.1093C>T, p.R365W was homozygous mutation. This disease is rare in clinic. Clinicians need to raise awareness of the disease for early diagnosis and treatment to improve the long-term prognosis of patients.
Subject(s)
46, XX Disorders of Sex Development/genetics , Adult , Aromatase/metabolism , Female , Gynecomastia/genetics , Humans , Infertility, Male , Male , Metabolism, Inborn Errors , Mutation , PregnancyABSTRACT
Acephalic spermatozoa syndrome (ASS) is one of the most severe spermatogenic failures of all infertility in men. The cognition of ASS has experienced a tortuous process. Over the past years, with the in-depth understanding of spermatogenesis and the emergence of new genetic research technologies, the unraveling of the genetic causes of spermatogenic failure has become highly active. From these advances, we established a genetic background and made significant progress in the discovery of the genetic causes of ASS. It is important to identify pathogenic genes and mutations in ASS to determine the biological reasons for the occurrence of the disease as well as provide genetic diagnosis and treatment strategies for patients with this syndrome. In this review, we enumerate various technological developments, which have made a positive contribution to the discovery of candidate genes for ASS from the past to the present. Simultaneously, we summarize the known genetic etiology of this phenotype and the clinical outcomes of treatments in the present. Furthermore, we propose perspectives for further study and application of genetic diagnosis and assisted reproductive treatment in the future.
Subject(s)
Humans , Infertility, Male/pathology , Male , Membrane Proteins/genetics , Mutation , Spermatogenesis/genetics , Spermatozoa/pathologyABSTRACT
Thanks to tremendous advances in sequencing technologies and in particular to whole exome sequencing (WES), many genes have now been linked to severe sperm defects. A precise genetic diagnosis is obtained for a minority of patients and only for the most severe defects like azoospermia or macrozoospermia which is very often due to defects in the aurora kinase C (AURKC gene. Here, we studied a subject with a severe oligozoospermia and a phenotypic diagnosis of macrozoospermia. AURKC analysis did not reveal any deleterious variant. WES was then initiated which permitted to identify a homozygous loss of function variant in the zinc finger MYND-type containing 15 (ZMYND15 gene. ZMYND15 has been described to serve as a switch for haploid gene expression, and mice devoid of ZMYND15 were shown to be sterile due to nonobstructive azoospermia (NOA). In man, ZMYND15 has been associated with NOA and severe oligozoospermia. We confirm here that the presence of a bi-allelic ZMYND15 variant induces a severe oligozoospermia. In addition, we show that severe oligozoospermia can be associated macrozoospermia, and that a phenotypic misdiagnosis is possible, potentially delaying the genetic diagnosis. In conclusion, genetic defects in ZMYND15 can induce complete NOA or severe oligozoospermia associated with a very severe teratozoospermia. In our experience, severe oligozoospermia is often associated with severe teratozoospermia and can sometimes be misinterpreted as macrozoospermia or globozoospermia. In these instances, specific AURKC or dpy-19 like 2 (DPY19L2) diagnosis is usually negative and we recommend the direct use of a pan-genomic techniques such as WES.
Subject(s)
Animals , Azoospermia/genetics , Humans , Infertility, Male/genetics , Male , Membrane Proteins/genetics , Mice , Mutation , Oligospermia/genetics , Repressor Proteins/metabolism , Teratozoospermia/geneticsABSTRACT
Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1% of azoospermia or severe oligospermia. However, the underlying mechanisms of pathogenesis and etiologies are still largely unknown. Herein, we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants. In addition, high read-depth genome sequencing (GS) (30-fold) was performed to investigate point mutations causative of male infertility. Mate-pair GS (4-fold) revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements. Overall, the breakpoints caused truncations of 30 RefSeq genes, five of which were associated with spermatogenesis. Furthermore, the breakpoints disrupted 43 topological-associated domains. Direct disruptions or potential dysregulations of genes, which play potential roles in male germ cell development, apoptosis, and spermatogenesis, were found in all cases (n = 6). In addition, high read-depth GS detected dual molecular findings in case MI6, involving a complex rearrangement and two point mutations in the gene DNAH1. Overall, our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility. We demonstrated the complexity of chromosomal structural rearrangements, potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.
Subject(s)
Azoospermia/genetics , Chromosome Aberrations , Humans , Infertility, Male/genetics , Male , Oligospermia/genetics , Translocation, GeneticABSTRACT
This study aims to compare the prevalence of sexually transmitted infections (STIs) with semen quality in men from couples with primary and secondary infertility. Semen samples were collected from 133 men who requested fertility evaluation. Seminal tract infection with Ureaplasma spp. (UU), Mycoplasma hominis (MH), Mycoplasma genitalium (MG), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and herpes simplex virus-2 (HSV-2) was assessed by PCR-based diagnostic assays. Among all patients, the prevalence of STIs was higher in men from couples with primary infertility than that in men from couples with secondary infertility (39.7% vs 21.7%, P = 0.03). The prevalence of UU was 28.8% and 13.3% in men from couples with primary and secondary infertility, respectively. Men from couples with primary infertility were more likely to be positive for UU than men from couples with secondary infertility (P = 0.04). Regarding the UU subtype, the prevalence of Ureaplasma urealyticum (Uuu) and Ureaplasma parvum (Uup; including Uup1, Uup3, Uup6, and Uup14) did not differ between the two groups. No associations between the prevalence rates of MH, MG, and CT were found in men from either infertility group. A lower sperm concentration was associated with STI pathogen positivity in men with primary infertility according to the crude model (P = 0.04). The crude and adjusted models showed that semen volume (both P = 0.03) and semen leukocyte count (both P = 0.02) were independently associated with secondary infertility. These findings suggest the importance of classifying the type of infertility during routine diagnosis of seminal tract infections.
Subject(s)
Female , Humans , Infertility, Male/epidemiology , Male , Mycoplasma genitalium , Mycoplasma hominis , Prevalence , Semen , Semen Analysis , Sexually Transmitted Diseases/epidemiology , Ureaplasma urealyticumABSTRACT
Nonobstructive azoospermia (NOA) is a common cause of infertility and is defined as the complete absence of sperm in ejaculation due to defective spermatogenesis. The aim of this study was to identify the genetic etiology of NOA in an infertile male from a Chinese consanguineous family. A homozygous missense variant of the membrane-bound O-acyltransferase domain-containing 1 (MBOAT1) gene (c.770C>T, p.Thr257Met) was found by whole-exome sequencing (WES). Bioinformatic analysis also showed that this variant was a pathogenic variant and that the amino acid residue in MBOAT1 was highly conserved in mammals. Quantitative polymerase chain reaction (Q-PCR) analysis showed that the mRNA level of MBOAT1 in the patient was 22.0% lower than that in his father. Furthermore, we screened variants of MBOAT1 in a broader population and found an additional homozygous variant of the MBOAT1 gene in 123 infertile men. Our data identified homozygous variants of the MBOAT1 gene associated with male infertility. This study will provide new insights for researchers to understand the molecular mechanisms of male infertility and will help clinicians make accurate diagnoses.
Subject(s)
Acetyltransferases/genetics , Animals , Azoospermia/genetics , Cell Cycle Proteins/genetics , Humans , Infertility, Male/genetics , Male , Mammals , Membrane Proteins/genetics , MutationABSTRACT
Environmental factors may negatively contribute to a progressive worsening of semen quality, and differences in semen quality may result from different environmental exposures (regional differences) or lifestyle differences. Heavy metals are factors with a confirmed negative influence on male fertility. Among them, lead and cadmium are commonly found in human surroundings. Thus, we analyzed semen parameters (according to the World Health Organization 2010 recommendations) and semen lead and cadmium concentrations in 188 men from two different regions in Poland, a typical agricultural area and an industrial area, in couples that had been diagnosed with infertility. The assays were performed using flameless electrothermal atomic absorption spectrometry. In the statistical analysis, regional comparisons and then taxonomic comparisons based on three parameters (age, semen concentration, and sperm morphology) were applied. We showed that more cadmium than lead accumulated in semen, a higher cadmium concentration was observed in semen obtained from men from the agricultural region, and better semen quality and lower cadmium concentrations were found in the semen of men from the industrial, more polluted region. We thus showed an existing regionalism in the sperm quality properties. However, semen parameters such as morphology and progressive and nonprogressive motility followed the same trends, regardless of the patient's age, region, or class. We could conclude that the environment has a minor impact on sperm morphology and progressive and nonprogressive motility and that other existing factors could have an indirect influence on semen quality.
Subject(s)
Cadmium , Environmental Exposure/analysis , Humans , Infertility, Male/chemically induced , Male , Semen , Semen Analysis , Sperm Count , Sperm Motility , SpermatozoaABSTRACT
Infertility affects 10%-15% of couples worldwide. Of all infertility cases, 20%-70% are due to male factors. In the past, men with severe male factor (SMF) were considered sterile. Nevertheless, the development of intracytoplasmic sperm injection (ICSI) drastically modified this scenario. The advances in assisted reproductive technology (ART), specifically regarding surgical sperm retrieval procedures, allowed the efficacious treatment of these conditions. Yet, before undergoing ICSI, male factor infertility requires careful evaluation of clinical and lifestyle behavior together with medical treatment. Epidemiologically speaking, women whose male partner is azoospermic tend to be younger and with a better ovarian reserve. These couples, in fact, are proposed ART earlier in their life, and for this reason, their ovarian response after stimulation is generally good. Furthermore, in younger couples, azoospermia can be partially compensated by the efficient ovarian response, resulting in an acceptable fertility rate following in vitro fertilization (IVF) techniques. Conversely, when azoospermia is associated with a reduced ovarian reserve and/or advanced maternal age, the treatment becomes more challenging, with a consequent reduction in IVF outcomes. Nonetheless, azoospermia seems to impair neither the euploidy rate at the blastocyst stage nor the implantation of euploid blastocysts. Based on the current knowledge, the assessment of male infertility factors should involve: (1) evaluation - to diagnose and quantify seminologic alterations; (2) potentiality - to determine the real possibilities to improve sperm parameters and/or retrieve spermatozoa; (3) time - to consider the available "treatment window", based on maternal age and ovarian reserve. This review represents an update of the definition, prevalence, causes, and treatment of SMF in a modern ART clinic.
Subject(s)
Azoospermia , Female , Fertilization in Vitro/methods , Humans , Infertility, Male/therapy , Male , Prevalence , Reproductive Techniques, Assisted , Sperm Injections, Intracytoplasmic/methods , SpermatozoaABSTRACT
Acephalic spermatozoa syndrome is a rare type of teratozoospermia that severely impairs the reproductive ability of male patients, and genetic defects have been recognized as the main cause of acephalic spermatozoa syndrome. Spermatogenesis and centriole-associated 1 like (SPATC1L) is indispensable for maintaining the integrity of sperm head-to-tail connections in mice, but its roles in human sperm and early embryonic development remain largely unknown. Herein, we conducted whole-exome sequencing (WES) of 22 infertile men with acephalic spermatozoa syndrome. An in silico analysis of the candidate variants was conducted, and WES data analysis was performed using another cohort consisting of 34 patients with acephalic spermatozoa syndrome and 25 control subjects with proven fertility. We identified biallelic mutations in SPATC1L (c.910C>T:p.Arg304Cys and c.994G>T:p.Glu332X) from a patient whose sperm displayed complete acephalia. Both SPATC1L variants are rare and deleterious. SPATC1L is mainly expressed at the head-tail junction of elongating spermatids. Plasmids containing pathogenic variants decreased the level of SPATC1L in vitro. Moreover, none of the patient's four attempts at intracytoplasmic sperm injection (ICSI) resulted in a transplantable embryo, which suggests that SPATC1L defects might affect early embryonic development. In conclusion, this study provides the first identification of SPATC1L as a novel gene for human acephalic spermatozoa syndrome. Furthermore, WES might be applied for patients with acephalic spermatozoa syndrome who exhibit reiterative ICSI failures.
Subject(s)
Centrioles/genetics , Homozygote , Humans , Infertility, Male/genetics , Male , Mutation , Spermatogenesis/genetics , SpermatozoaABSTRACT
Chlamydia trachomatis (CT) infection is the most prevalent sexually transmitted bacterial disease worldwide. However, unlike that in female infertility, the role of CT infection in male infertility remains controversial. The objective of this retrospective study was to explore the impacts of CT infection in the genital tract on sperm quality, sperm acrosin activity, antisperm antibody levels, and inflammation in a large cohort of infertile males in China. A total of 7154 semen samples were collected from infertile male subjects, 416 of whom were CT positive (CT+ group) and 6738 of whom were CT negative (CT- group), in our hospital between January 2016 and December 2018. Routine semen parameters (semen volume, pH, sperm concentration, viability, motility, morphology, etc.), granulocyte elastase levels, antisperm antibody levels, and sperm acrosin activity were compared between the CT+ and CT- groups. Our results showed that CT infection was significantly correlated with an abnormally low semen volume, as well as an increased white blood cell count and granulocyte elastase level (all P < 0.05) in the semen of infertile males; other routine semen parameters were not negatively impacted. The antisperm antibody level and sperm acrosin activity were not affected by CT infection. These findings suggested that CT infection might contribute to inflammation and hypospermia but does not impair sperm viability, motility morphology, and acrosin activity or generate antisperm antibodies in the infertile males of China.
Subject(s)
Chlamydia trachomatis , Female , Genitalia , Humans , Infertility, Male/epidemiology , Inflammation/epidemiology , Male , Retrospective Studies , Semen , SpermatozoaABSTRACT
Semen analysis has long been used to evaluate male fertility. Recently, several sperm function tests have been developed. Of those, the sperm DNA fragmentation index (DFI), which describes the status of the sperm DNA, is thought to be a suitable parameter for evaluating male fertility. However, there have been no large-scale studies on the sperm DFI of Japanese men. Therefore, we investigated the feasibility of using an in-house flow cytometry-based sperm DFI analysis based on the sperm DNA fragmentation test of sperm chromatin structure assay (SCSA) to assess male fertility in Japan. This study enrolled 743 infertile and 20 fertile Japanese men. To evaluate reproducibility, inter- and intraobserver precision was analyzed. A receiver operating characteristic curve analysis was used to set a cutoff value for the sperm DFI to identify men who could father children by timed intercourse or intrauterine insemination. The variability of the sperm DFI among fertile volunteers was determined. The relationship between semen parameters and the sperm DFI was assessed by Spearman's rho test. A precision analysis revealed good reproducibility of the sperm DFI. The cutoff value of sperm DNA fragmentation in infertile men was 24.0%. Semen volume had no relationship with the sperm DFI. Sperm concentration, sperm motility, total motile sperm count, and percentage of normal-shaped sperm were significantly and negatively correlated with the sperm DFI. The median sperm DFI was smaller in fertile volunteers (7.7%) than that in infertile men (19.4%). Sperm DNA fragmentation analysis can be used to assess sperm functions that cannot be evaluated by ordinary semen analysis.