Accurate sperm morphology assessment predicts sperm function

Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.     

Evaluation and assessment of semen for IVF/ICSI

Evaluation and assessment of semen is very important for both diagnosis of male infertility and selection of patients for treatment with IVF or ICSI. In standard IVF, sperm function is essential for normal fertilization: sperm must be able to bind to zona pellucida (ZP), undergo the acrosome reaction and penetrate the ZP and fuse with the oolemma before fertilization takes place. In contrast, most sperm functions are not required for fertilization in ICSI since sperm bypass the ZP and oolemma by injection of a single sperm directly into cytoplasm of oocyte. Therefore, the clinical decision on treatment of patients with either IVF or ICSI is mostly dependent on results of sperm tests. However, conventional semen analyses do not provide accurate information about sperm fertilizing ability since many patients with subtle sperm defects can not be detected. More advanced sperm function tests are required to detect sperm defects that may lead to failure of fertilization in standard IVF. In the last 15 years w     

Reappraisal of the hypo-osmotic swelling test to improve assessment of seminal fertility status

The hypo-osmotic swelling (HOS) test has been proposed as a useful assay for evaluation of the functional competence of the human sperm membranes. To assess this further, the HOS-test was evaluated in 187 semen samples collected from fertile men and from male patients consulting for infertility. These samples were classified as normal, oligo-, astheno- or oligoasthenozoospermic on the basis of their standard semen variables. The percentage of total sperm tail swelling and of sperm exhibiting different tail swelling patterns was recorded. In the fertile men and in the group of patients with normal semen variables, significantly more (P less than 0.001) HOS-reactive sperm were observed after hypo-osmotic treatment in comparison with those groups exhibiting abnormal semen parameters. Swelling of the sperm in a hypo-osmotic medium was highly correlated with both progressive motility (r = 0.62, P less than 0.001) and sperm viability (r = 0.65, P less than 0.001). A weak positive correlation was also observed between sperm swelling and sperm morphological features (r = 0.31, P less than 0.005) and between sperm swelling and sperm concentration (r = 0.31, P less than 0.005). No significant correlation was observed between sperm swelling and in-vitro sperm fertilizing capacity as assessed by the zona-free hamster oocyte penetration assay. However the majority of the semen samples (87.3%) showing a normal penetration rate (greater than or equal to 10%) also exhibited a 60% (or higher) reaction in the HOS-test.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical correlates of the biological variation of sperm DNA fragmentation in infertile men attending an andrology outpatient clinic

Determination of sperm DNA fragmentation, as assessed by the sperm chromatin structure assay (SCSA), has become an important tool for the evaluation of semen quality. The aim of the present study was to describe the biological variation of sperm DNA fragmentation in men attending an andrology clinic and to identify clinical correlates of the biological variation of sperm DNA fragmentation. For this study, two consecutive semen samples from 100 patients attending our andrology outpatient clinic were subjected to semen analysis, performed in parallel according to WHO guidelines and by SCSA. A good agreement between pairs of samples was found for SCSA-derived variables, as indicated by a significantly lower median coefficient of variation (CV) of the DNA Fragmentation Index (DFI) and the high DNA stainability (HDS) compared with WHO semen parameters. In half of the men attending our andrology clinic, however, the individual biological variation of DFI and HDS, expressed as CV of two samples, exceeded 10%. Dysregulation of spermatogenesis, as seen as testicular insufficiency or varicocele, was not associated with increased variability of DFI or HDS. A backward multiple linear regression analysis, however, indicated that the biological variation of DFI may be more profound in men with characteristics of normal spermatogenesis. In conclusion, we confirm previous reports that sperm DNA fragmentation has a lower biological variability than classical semen parameters. We hypothesize that the sperm chromatin structure may be more influenced in patients with normal spermatogenesis, whereas in men with disturbed spermatogenesis, the chromatin structure may be already so impaired that the effect of unidentified factors leading to variability of sperm DNA fragmentation in time may not be as profound.     

Assessment of sperm hyperactivated motility and acrosome reaction can discriminate the use of spermatozoa for conventional in vitro fertilisation or intracytoplasmic sperm injection: Preliminary results

Basic semen analysis is insufficient for determining the fertility potential. The aim of this study was to determine if hyperactivated motility (HAM) and acrosome reaction (AR) can be useful tests for evaluating semen quality during male infertility evaluations and to help the clinician decide whether regular insemination or intracytoplasmic sperm injection (ICSI) is preferable during in vitro fertilisation. A prospective study was conducted. Patients with normal sperm according to World Health Organization guidelines who underwent IVF treatment and planned regular insemination were asked to participate. A portion of sperm sample was evaluated for HAM and AR on day of ovum pick up. In HAM assessment, 93.3% of patients with increased HAM had a high fertilisation rate compared with 64% in the group without increased HAM (P = 0.059). For the AR evaluation, 91.7% of samples with a low rate of spontaneous AR had a high fertilisation rate compared with 39.3% in the group with a high rate of spontaneous AR (P = 0.004).     

Effect of varicocele on chromatin condensation and DNA integrity of ejaculated spermatozoa using cytochemical tests

Varicocele occurs in approximately 15% to 20% of the general male population and it is the most common cause of poor semen production and decreased semen quality. It has been demonstrated that patients with varicocele have a significantly higher DNA fragmentation index (DFI) and spermatozoa with nuclear anomalies than healthy fertile men. Therefore, the aim of this study was to evaluate sperm chromatin integrity in these patients. Sixty men referring to the andrology laboratory were categorised into three different groups: 20 infertile men with varicocele, 20 infertile men with abnormal semen parameters and 20 fertile men who had normal spermatogram were considered as control group. Semen analysis was performed according to WHO criteria. To evaluate sperm chromatin quality and DNA integrity, after fixation of sperm smears, aniline blue, toluidine blue, chromomycin A₃ and acridine orange staining were applied in three groups. The slides were analysed by light and fluorescent microscopy and to determine the percentage of mature or immature spermatozoa, 200 spermatozoa were counted in each slide. The results showed that the rates of aniline blue-reacted spermatozoa were significantly higher in infertile and varicocele patients than in the normal group ( P  < 0.001). In addition, with regard to chromomycin A₃, acridine orange and toluidine blue staining, there was a significant difference between the three groups ( P  < 0.001). The results showed that the varicocele samples contain a higher proportion of spermatozoa with abnormal DNA and immature chromatin than those from fertile men as well as infertile men without varicocele. Therefore, varicocele results in the production of spermatozoa with less condensed chromatin and this is one of the possible causes of infertility due to varicocele.     

男性不育患者精子DNA中8—羟基脱氧鸟苷水平及与精液参数的相关性

本文应用高压液相 电化学 (HPLC EC)技术对 5 2名男性不育患者精子DNA中 8 羟基脱氧鸟苷 (8 OHdG)进行测定 ,同时检测精液量、精子密度、精子活率、正常形态精子率 ,及头部精子畸形等精液参数 ,并进行相关性分析。结果显示 ,当精子DNA中 8 OHdG超过 10 .5 0时 ,其头部畸形率明显增加。精子DNA中 8 OHdG与精液量 (r =- 0 .4 7,P <0 .0 0 1)、正常形态精子率 (r=- 0 .36 ,P <0 .0 1)成一定的负相关 ,且与头部畸形精子率成正相关 (r =0 .6 9,P <0 .0 0 1)。结果提示 ,精子DNA中 8 OHdG与精液质量存在一定的相关性 ,表明精液质量的下降与精子DNA的损伤存在一定联系 ,而内源及外源性活性氧是可能的原因之一 ,其可能的机制尚需进一步研究。     

Normal sperm morphology and chromatin packaging: comparison between aniline blue and chromomycin A3 staining

The successful implementation of ICSI has provided a unique means of allowing couples suffering from severe male infertility to achieve their reproductive goals. However, despite the great therapeutic advantages of the technique, ICSI often provides solutions to clinicians in the absence of an aetiological or pathophysiological diagnosis. The development of a sequential diagnostic schedule for patients consulting for fertility disturbances would be an ideal method of approach. Since sperm morphology recorded by strict criteria has often been correlated with fertilization failure, the present study aimed to evaluate the relationship between normal morphology and chromatin staining among fertile and subfertile men. Both chromomycin A3 (CMA3) and acidic aniline blue (AAB) were employed to record chromatin packaging quality among 58 men visiting the andrology laboratory. Intra- and interassay variations were initially recorded for fertile sperm donors. The coefficients of variation (CV) for all intra- and inter-assay assessments were < 12%. Chromatin packaging was significantly and negatively correlated with normal sperm morphology, namely r = 0.40 (P = 0.001) and r = 0.33 (P = 0.001) for CMA3 and AAB, respectively. Receiver operator characteristics illustrated sensitivity and specificity values of 75% and 82% for CMA3 and 60% and 91% for AAB, respectively. Significantly different CMA3 and AAB staining was recorded among men with severe teratozoospermia (< 4% normal forms) when compared with normozoospermic men (> 14% normal forms), namely 49% vs. 29% for CMA3 and 51% vs. 26% for AAB staining, respectively. Chromatin packaging assessments should be a valuable addition to the sequential diagnostic programme in an assisted reproduction arena.     

精浆游离L-肉毒碱水平及其与精子密度、活动率及活力的相关性研究

目的:研究正常生育及不育男性精浆中游离L-肉毒碱水平差异及其与精子密度、活动率(a+b+c级精子百分率)及活力(a+b级精子百分率)之间的相关性,探讨精浆中游离L-肉毒碱水平对男性生育力的影响及其在不育症检查和治疗中的作用。方法:分别采用高效液相色谱法和计算机辅助精液分析系统,测定了230例不育症患者(精子密度正常117例,少精子症81例,无精子症32例)和30例正常生育男性精浆中游离L-肉毒碱水平及精子密度、活动率、活力等参数。根据检查结果对不育症患者分组后,以SPSS12.0软件包进行统计学分析,比较各组间游离L-肉毒碱水平的差异以及游离L-肉毒碱水平与精子密度、活动率、活力之间的相关性。结果:正常生育组精浆游离L-肉毒碱水平明显高于不育组(P<0.01)。精液中精子密度越低、活力越弱,这种差异性越显著。相关性分析结果显示,精浆游离L-肉毒碱水平与精子密度呈显著正相关关系(r=0.521,P<0.01),与精子活动率和活力之间也具有正相关关系(r=0.319,P<0.01;r=0.251,P<0.01)。结论:精浆L-肉毒碱水平与精子密度、活动率和活力之间密切相关,其含量测定作为一项有用的生化指标,可为男性不育症检查及临床诊治和进行有关男性生殖功能机制研究提供参考。     

Evidence for association of sex hormone-binding globulin and androgen receptor genes with semen quality

The roles of androgen receptor AR(CAG)n gene polymorphisms and sex hormone-binding globulin SHBG(TAAAA)n gene polymorphisms on semen quality were studied. One hundred fourteen men were included in the study: 85 with normal sperm count and 29 oligospermic. The genotype analysis, on DNA extracted from spermatozoa, revealed five SHBG(TAAAA)n alleles with 6–10 repeats and 18 AR(CAG)n alleles with 12–32 repeats. The SHBG allelic distribution showed that in men with normal sperm count and motility, those with short SHBG alleles had higher sperm concentration than men with long SHBG alleles ( P  = 0.039). As concerns AR(CAG)n polymorphisms, men with short AR alleles had lower sperm motility compared to those with long AR alleles ( P  < 0.001) in both total study population and normal sperm count men. The synergistic effect analysis of the two polymorphisms revealed an association between sperm motility ( P  = 0.036), because of the effect of AR(CAG)n polymorphism on sperm motility. In conclusion, long AR alleles were found to be associated with higher sperm motility, while short SHBG alleles were associated with higher sperm concentration, supporting the significance of these genes in spermatogenesis and semen quality.     

Semen analysis and sperm function testing

Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization (WHO) manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external quality control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.     

Sperm nuclear DNA fragmentation and its association with semen quality in Greek men

Due to the limitations of conventional semen analysis in predicting a man's fertility potential, sperm DNA fragmentation was recently introduced as a novel marker of sperm quality. This prospective study was undertaken to investigate the associations between conventional seminal parameters and DNA fragmentation in Greek men. A total of 669 subject data were evaluated in two groups, normozoospermic (n = 184) and non‐normozoospermic (n = 485), according to the WHO 2010 (WHO Laboratory Manual for the Examination and Processing of Human Semen, 5th edn. World Health Organization), reference limits. For all the subjects, semen volume, sperm concentration, total count, rapid and total progressive motility and morphology were recorded following the WHO 2010 methods and DNA fragmentation was assessed by the sperm chromatin dispersion assay. An inverse correlation was established between DNA fragmentation and all conventional seminal parameters except semen volume in men with seminal profiles below the reference limits, with statistical significance for rapid and total progressive motility. Normozoospermic men exhibited lower levels of DNA fragmentation than their non‐normozoospermic counterparts, even though the values were not always below 30%. DNA fragmentation testing and traditional semen analysis should therefore be considered as complementary diagnostic tools in a comprehensive evaluation of male infertility.     

The influence of homogenous zona pellucida on human spermatozoa hyperactivation, acrosome reaction and zona binding

The study aimed to evaluate the changes in sperm motion characteristics and the occurrence of hyperactivation among sperm populations after exposure to human zona pellucida. Motile spermatozoa samples were used to evaluate the sperm-zona binding capacity, zona-induced acrosome reaction and changes in sperm motion characteristics. Sperm motion characteristic changes studied included straight line velocity, curvilinear velocity, amplitude of lateral head displacement, straightness and beat cross frequency. Recordings were performed on semen immediately after liquefaction, 3 h capacitation and after exposure to solubilised human zona pellucida. The semen samples were divided into morphology categories, namely six (16 +/- 1.4% normal forms, normal patterns), 31 (8 +/- 1.7% normal forms, G-pattern) and 27 (3 +/- 1.3% normal forms, P-pattern). The Hemizona Indices for the three morphology groups namely normal, G-patterns and P-patterns, were 77 +/- 6%, 61 +/- 5% and 41 +/- 5% respectively (P 相似文献   

精子功能检测与男性不育诊治的新进展

传统的精液常规分析是用于判断男性生育力的最基本临床指标,但是,只依靠精液分析的结果来预测男性生育状况仍是很不准确的。精子功能正常与否,对临床选择IVF还是ICSI治疗不育症极为重要。因为IVF需要功能完全正常的精子才能受精,而ICSI的受精只需要精子的正常核DNA,不需要其它的精子功能。在发明ICSI以前,患者IVF受精失败或低下(<30%)发生率很高(20%~35%)。研究证明,这些IVF受精失败的患者主要与精子功能障碍有关。常见的是少精子症,弱精子症和畸形精子症。但是有很多患者,精液分析结果仍正常。为了提高临床对精子功能测定的准确性,文献里有很多新的精子功能试验的研究报导,比如丫啶橙(AO)测定精子DNA、精子与透明带结合和穿透、顶体诱发精子顶体反应和精子与透明质酸结合试验。精子形态测定是常规精液分析中最重要的临床指标之一。但精子形态又是最难测定准确和稳定。IVF/ICSI受精失败的人卵可以用来测定精子功能。人卵透明带选择性地与正常形态和顶体完整的精子结合,透明带诱发的顶体反应与精子穿透明带的能力有很强的相关性。在不明原因的男性不育患者中,由于透明带诱发顶体反应障碍所导致的不育症占25%左右。少精子症(精子计数<2×106/ml)和严重精子形态畸形症(严格正常形态<5%)的男性不育患者,精子-透明带结合反应缺陷的发生率很高(>70%)。这类患者用IVF治疗受精率会很低,因此只能用ICSI治疗。精子与透明质酸结合试验与精子活力和形态有很强的相关性,但它不是很有用的精子功能试验。AO测定精子DNA对预测ART的受精和妊娠率的临床意义目前还没有肯定的结论,需要进一步研究。总之,在常规精液分析时,增加一些新的精子功能试验,在临床ART中对男性不育患者的诊治会有很大的帮助。     

司机职业不育男性的精液分析

目的 :探讨司机职业与男性精液质量有无相关性。　方法 :对 12 2 3例不育男性 (司机 78例、非司机 114 5例 )和 10 0例生育男性精液从液化、精子密度、精子活力、精子活率、精子形态等方面进行全面分析。　结果 :从事司机职业的不育男性精液质量异常率显著高于非司机职业不育男性 (P <0 .0 5 )和生育男性 (P <0 .0 1) ,且开车 8年以上组精液质量异常率显著高于开车 8年以下组 (P <0 .0 5 )。　结论 :司机职业可引起男性精液质量异常。     

Trends in semen parameters in the northeast of Scotland

The data on trends in semen quality are conflicting and sensitive to geographical variations. Although previous British surveys on semen quality indicate a decline, the northeast of Scotland has never been included in these surveys. This is an area with low out migration rates where andrology services for a population of 500 000 are centralized within a single laboratory, thus providing a unique opportunity to study population-based trends in semen quality over time. We investigated trends in semen parameters between 1994-2005, in a cohort of 4832 men attending for routine semen analysis at the Aberdeen Fertility Centre who had a sperm density of greater than 20 million per mL. The main outcome measures were trends in sperm density, sperm motility and motile density in the first semen sample. Linear regression and time series analysis were used to examine trends over time in the semen parameters. The mean and standard deviation (SD) age of all men (n=5204) in the study was 34(6) years. The median (inter quartile range) for sperm density and motile density for the study population were 61 (40-91) million/mL and 99 (47-181) million. The mean (SD) sperm motility was 49 (19)%. Among 4832 men (with sperm count >20 million per mL), data adjusted for age and period of abstinence showed a decreasing trend for sperm density over time, R2=0.45 (P=.017). There was no such trend in sperm motility and motile density. However, this trend has to be interpreted with caution due to fluctuations in semen parameters, population bias and the retrospective nature of the analysis.     

Sperm DNA fragmentation

Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couple's fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trails before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists. Extensive investigation has been conducted for the comparative evolution of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories. Sperm chromatin structure evaluation is applied to detect male factors that may affect the chance of success with IVF as well as natural fertility. Further research is needed to define the optimal test of sperm chromatin structure. The clinical application of this test will evolve as well.     

Prediction of spontaneous conception based on semen parameters

Accurate prognosis of male fertility based on semen measurements is still not straightforward. This study was designed to identify the best predictors of fertility and to develop a multiple regression model predicting fertility using selected parameters of semen analysis. The predictive value of standard semen parameters and selected functional tests were studied in 113 fertile men and in 109 subfertile men whose spouses had a normal infertility workup. Individual semen parameters were evaluated using the receiver operating characteristic curve. Logistic regression based on linear functions of analysed sperm parameters was used to predict the chance of spontaneous conception. Logistic regression modelling revealed that the best prediction of spontaneous conception was obtained using 12 semen parameters: sperm concentration, total progressive motility (A + B), motility grade C or D, normal sperm morphology, defects of: head, acrosome, midpiece and tail, spontaneous acrosome reaction, hypo-osmotic swelling (HOS) test and acid aniline blue test. This mathematical model reached 90.3% accuracy in predicting in vivo conception and 90.8% for its lack. A satisfactory prediction of male fertility was also obtained using only four semen measurements: sperm concentration, total progressive motility (grade A + B), normal morphology, and HOS test; this model correctly identified as fertile 84.1% of those who conceived and identified as subfertile 88.1% of those who did not achieve pregnancy. In conclusion, basic semen analysis and selected functional tests of sperm provide important information regarding male fertility status.     

Seminal parameters of chronic male genital inflammation are associated with disturbed sperm DNA integrity

Definition of chronic male genital tract inflammation and its impact on male infertility is still a matter of debate. In particular, DNA integrity has been reported to be disturbed in subfertile men. Thus, the aim of this study was to investigate an association of DNA integrity to altered standard semen parameters as well as inflammatory parameters such as peroxidase‐positive cells, macrophages and seminal interleukin‐6 concentration. Macrophages were detected by CD18/HLA‐Dr staining, and DNA integrity was analysed by acridine orange staining using flow cytometry. Interleukin‐6 was detected by ELISA. Normal DNA integrity showed a significant correlation to sperm number and progressive motility. Moreover, a significant inverse correlation of DNA integrity to Interleukin‐6 and macrophages could be demonstrated. Further on, seminal interleukin‐6 also significantly correlated to macrophages. No association has been observed between the number of peroxidase‐positive cells and normal DNA integrity. As disturbed DNA integrity has been reported to negatively influence spermatozoon–egg interaction and even fertilisation rates following ICSI, and as early miscarriages have been associated with sperm DNA damage, it should be screened very carefully for male genital tract inflammations in couples undergoing infertility treatment. Measuring Interleukin‐6 seems superior to assessment of the number of leucocytes alone and additional assessment of DNA integrity into the diagnostic work‐up should be considered.     

Male age is more critical to sperm DNA integrity than routine semen parameters in Chinese infertile males

This retrospective study evaluated the correlation between the sperm DNA integrity results and infertile male age or sperm motility in 654 infertile men undergoing infertility evaluations from 2013 to 2016. The correlation between the results of sperm DNA integrity and male age was positive, while a negative correlation was detected between sperm DNA integrity and sperm motility in all subjects. According to age (≤30, 30–35 and ≥35), men with normozoospermia or abnormal semen parameters were, respectively, divided into groups 1, 2 and 3, or groups A, B and C. The sperm DNA fragmentation index (DFI) and DFI abnormality rates in groups 3 and C were highest among their respective cohorts. But they were not significantly different between groups within the same age range. Statistically significant differences were found in male age, progressive motility, as well as total motility between patients with normal DFIs and those with abnormal DFIs in group C, but not in group 3. Older (≥35 years) infertile men have increased sperm DNA fragmentation, independent of conventional semen parameters. Male age is more critical to sperm DNA integrity than routine semen parameters.