The relationship between DNA fragmentation and the intensity of morphologically abnormal human spermatozoa

Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization definitions.Sperm morphology was assessed using bright field microscopy.Sperm DNA fragmentation was assessed using the sperm chromatin dispersion assay.Non-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm DNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this relationship.Results:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SDF(Spearman's Rho=-0.230;P<0.001).Significant differences in the proportion of SDF were found when all cohorts were compared(P<0.001);these significant differences were also retained when the different cohorts were compared pairwise.ROC analysis showed a moderate but significant predictive value for SDF to differentiate patients with different levels of teratozoospemia.Conclusions:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SDF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram.

Early apoptotic changes in human spermatozoa and their relationships with conventional semen parameters and sperm DNA fragmentation

Aim： To investigate whether early apoptotic changes in spermatozoa can be significant markers for sperm quality. Methods： Two early apoptotic changes in the semen of 56 men were assessed using Annexin V （AN）/propidium iodide （PI） staining for phosphatidylserine externalization and JC-1 staining for mitochondrial membrane potential （MMP）. The results were compared with conventional semen parameters and DNA fragmentation identified using the TUNEL assay. Results： The different labeling patterns in the bivariate Annexin V/PI analysis identified four distinctive spermatozoa populations. The percentage of AN^-/PI^- spermatozoa positively correlated with conventional semen parameters and MMP, but negatively correlated with TUNEL （＋） spermatozoa. As for the AN^-/PI^＋ fraction, we found an opposite result in comparison to AN^-/PI^- spermatozoa. The level of early apoptotic AN^＋/PI^- spermatozoa negatively correlated with MMP and sperm motility. The level of late apoptotic AN^＋/PI^＋ spermatozoa negatively correlated with conventional semen parameters and MMP, and positively correlated with TUNEL （＋） spermatozoa. MMP positively correlated with conventional semen parameters, but negatively correlated with TUNEL （＋） spermatozoa. Conclusion： Although early apoptotic AN^＋/PI^- spermatozoa only negatively correlates with sperm motility, the differences in proportion of each subpopulation of spermatozoa （especially, the percentage of AN^-/PI^- spermatozoa）, and decreased MMP might be significant markers for diagnosing male infertility. They possibly bring additional information to predict the outcome of in vitro fertilization. （Asian J Androl 2008 Mar; 10： 227-235）

Can DNA fragmentation of neat or swim-up spermatozoa be used to predict pregnancy following ICSI of fertile oocyte donors？

This study compared the potential of assessing sperm DNA fragmentation （SDF） from neat semen and the subsequent swim-up （SU） procedure to predict pregnancy when conducting ICSI of fertile donor oocytes. Infertile females （n=81） were transferred embryos resulting from intracytoplasmic sperm injection （ICSI） of their partner＇s spermatozoa and proven donor oocytes. This model normalized the impact of female factor in putative sperm DNA repair. Semen was blindly assessed for SDF using Halosperm immediately following ejaculation （NS） and after swim-up at the time of ICSI fertilisation. There was a decrease in SDF values of the ejaculated semen sample following the swim-up protocol （P=0.000）. Interestingly, pregnancy could be equally predicted from SDF values derived from either neat or swim-up semen samples. Receiver operator curves and the derived Youden＇s indices determined SDF cutoff values for NS and SU of 24.8% and 17.5%, respectively. Prediction of pregnancy from NS SDF had a sensitivity of 75% and a specificity of 69%, whereas for SU SDF was 78% and 73%, respectively. While increased levels of SDF negatively impact reproductive outcome, we have shown that a reduction in SDF following sperm selection using ICSI with proven donor oocytes is not mandatory for achieving pregnancy. This suggests that a certain level of DNA damage that is not detectable using current technologies could be impacting on the relative success of assisted reproductive technology （ART） procedures. Consequently, we propose a modification of the so called ＇iceberg model＇ as a possible rationale for understanding the role of SDF in reproductive outcome.

基于中医证候与精液质量相关参数构建精子DNA碎片预测模型与验证

背景:中医证候与精液质量相关参数相结合,共同预测精子DNA碎片指数(DNA fragmentation index,DFI)异常增高的发生并绘制列线图,能显著提高临床的实操性与应用效能,为临床全面评估精液质量,采取积极干预措施以改善临床结局及制定个体化医疗方案提供依据。目的:探讨基于中医证候与精液质量相关参数构建精子DNA碎片的预测模型与验证。方法:回顾性分析2019年7月至2021年7月在广西壮族自治区南溪山医院中医男科接受中医证候诊断及精子DNA碎片率检查的不育患者共420例,据《人类精液检查与处理实验室手册》(第6版),将其中137例精子DFI>30%患者纳入精子DFI异常增高组,将283例精子DFI≤30%作为对照组;首先采用单因素分析筛选精子DFI异常增高的影响因素,然后采用套索算法(LASSO)校正因子共线性问题并筛选出最佳匹配因子后,将其纳入多因素向前逐步Logistic回归找出其独立影响因素并绘制列线图,最后采用受试者工作曲线、校准曲线、临床决策曲线、临床影响曲线对该预测模型进行区分度与准确度及临床应用效能验证。结果与结论:①单因素分析结果显示,年龄、体质量指数、前向运动率、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证为引发精子DFI异常增高的影响因子(P<0.05);②通过LASSO回归进一步筛选出的最佳匹配因素为年龄、体质量指数、精子总活率、精子浓度、精子形态学、肾阳虚衰证、湿热下注证、肾精不足证(P<0.05);③多因素向前逐步Logistic回归结果显示年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证共6项为引发精子DFI异常增高的独立影响因素;④受试者工作曲线显示,模型组曲线下面积为0.760(0.713,0.806),验证组曲线下面积为0.745(0.714,0.776),说明该预测模型具有较好的区分度;⑤校准曲线平均绝对误差0.040,Hosmer-Lemeshow检验P>0.05,表明该模型预测发生精子DFI异常增高的概率与实际发生精子DFI异常增高的概率无显著统计学差异,证实该模型具有较好的准确度;⑥临床决策曲线与临床影响曲线显示,模型组与验证组分别在阈概率值为0.08-0.84与0.09-0.78时具有临床最大净获益,且在该阈概率范围内具有较好的临床应用效能;⑦结果表明,年龄、体质量指数、精子浓度、精子总活率、湿热下注证、肾阳虚衰证为引发精子DFI异常增高的独立影响因素,通过其构建的临床预测模型列线图具有较好的临床预测价值与临床应用效能,可为临床全面评估精液质量、预后与干预及个体化医疗服务提供依据。

基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性

背景:精子DNA碎片指数与受精、胚胎发育潜能、胚胎植入、流产及子代安全性等存在显著的相关性。然而,其临床参考值受多种因素的影响,导致临床意义极其有限,该研究以活产为结局,通过倾向评分匹配校正其他混杂因素后,构建精子DNA碎片指数与活产的最佳临床截断值,并对其进行内外部验证,具有较好的预测价值及临床应用效能。目的:探讨基于活产建立体外受精-胚胎移植精子DNA碎片指数的参考阈值及子代短期安全性。方法:选取2019年5月至2021年5月于常州市妇幼保健院接受体外受精-胚胎移植患者1921例,以倾向匹配容差0.02为标准,1∶1进行倾向评分匹配,结果活产组与非活产组各成功匹配540例,以此建立模型组;通过选取同时期广西壮族自治区南溪山医院接受体外受精-胚胎移植患者135例作为外部验证组;采用受试者工作曲线探求精子DNA碎片指数对活产的临床最佳截断值,分别采用限制性立方样条曲线、标准曲线、临床决策曲线、临床影响曲线及内外部验证等方法,对该截断值的准确性及临床应用效能进行评估。结果与结论:(1)非活产组精子DNA碎片指数显著高于活产组且与活产存在显著的负相关性(r=-0.444,P<0.001);(2)受试者工作曲线结果显示,DNA碎片指数对活产的最佳截断值为24.33%,曲线下面积为0.775(0.746,0.804),特异度为72.60%,敏感度为78.90%,准确度为75.70%;(3)限制性立方样条曲线拟合Logistic回归结果显示,当精子DNA碎片指数大于24.57%时,临床非活产的风险呈趋势性增涨;(4)Logistic回归概率分析结果显示,精子DNA碎片指数为活产的危险因素[OR(95%CI)=0.916(0.904,0.928),P<0.001],且当精子DNA碎片指数大于27.78%时,临床活产发生的概率将小于50%,随着精子DNA碎片指数每增高1个单位,活产的概率下降8.4%;(5)内外部对该临床截断值的验证均显示,该截点具有一定的临床预测价值及准确性;(6)临床决策曲线与临床影响曲线显示,以该临床截断值建立的预测模型在阈概率为0.22-0.73时具有临床最大净获益值,且在该阈概率范围内损失与获益的比值始终小于1,证实该预测模型具有较好的临床应用效能;(7)精子DNA碎片指数与子代短期安全性分析结果显示,精子DNA碎片指数与出生儿早产、体质量、畸形、性别差异无显著性;(8)结果表明,精子DNA碎片指数对体外受精-胚胎移植活产的最佳临床截断值为24.33%,以此建立的临床预测模型具有较好的区分度、准确度与临床应用效能,精子DNA碎片指数对子代短期安全性影响并不显著,但仍需大样本及长期的追踪评估。

Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic male patients

Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.

Single sperm selection and DNA fragmentation analysis: The case of MSOME/IMSI

Sperm of poor quality may affect syngamy after fertilization, embryo development up to the blastocyst stage and reproductive outcome. Subsequently, sperm selection based on morphological characteristics and sperm DNA quality may help to partially avoid these problems. Today, highly efficient sperm selection based on morphological characteristics can be attained using the motile sperm organelle morphology (MSOME) examination, and the spermatozoa selected can be used for ICSI through a fertilization strategy known as intra-cytoplasmic morphologically selected sperm injection (IMSI). The aim of this investigation was to develop a simple methodology to assess sperm DNA fragmentation in single spermatozoa following MSOME/ IMSI, to test the hypothesis that morphologically normal spermatozoa, with an absence of vacuolization, is free of DNA damage. The results indicated that MSOME/IMSI-selected sperm, combined with the Sperm Chromatin Dispersion test (SCD;Oligo-Halosperm), can be reliably used to assess sperm DNA damage in selected single spermatozoa (75% average efficiency), thereby establishing a direct relationship between a good morphological pattern on the sperm and a good DNA quality. Furthermore, results showed spermatozoa presenting a normal morphology and no traces of vacuolization to be fully free of DNA damage. However, traces of vacuolization and more severe morphological alterations were accompanied by significant increases in the proportion of sperm containing a damaged DNA molecule. Interestingly, subtle morphological differences observed between normal and non-vacuolated and normal but vacuolated sperm exhibited significant differrences in the ability of the SCD-Oligo-Halosperm treated sperm to expand DNA fibers following protein depletion.

New approach to assess sperm DNA fragmentation dynamics： Fine-tuning mathematical models

Background： Sperm DNA fragmentation（sDF） has been proved to be an important parameter in order to predict in vitro the potential fertility of a semen sample. Colloid centrifugation could be a suitable technique to select those donkey sperm more resistant to DNA fragmentation after thawing. Previous studies have shown that to elucidate the latent damage of the DNA molecule, sDF should be assessed dynamically, where the rate of fragmentation between treatments indicates how resistant the DNA is to iatrogenic damage. The rate of fragmentation is calculated using the slope of a linear regression equation. However, it has not been studied if s DF dynamics fit this model. The objectives of this study were to evaluate the effect of different after-thawing centrifugation protocols on sperm DNA fragmentation and elucidate the most accurate mathematical model（linear regression, exponential or polynomial） for DNA fragmentation over time in frozen-thawed donkey semen.Results： After submitting post-thaw semen samples to no centrifugation（UDC）, sperm washing（SW） or single layer centrifugation（SLC） protocols, sD F values after 6 h of incubation were significantly lower in SLC samples than in SW or UDC.Coefficient of determination（R-2） values were significantly higher for a second order polynomial model than for linear or exponential. The highest values for acceleration of fragmentation（aSDF） were obtained for SW, fol owed by SLC and UDC.Conclusion： SLC after thawing seems to preserve longer DNA longevity in comparison to UDC and SW. Moreover,the fine-tuning of models has shown that sDF dynamics in frozen-thawed donkey semen fit a second order polynomial model, which implies that fragmentation rate is not constant and fragmentation acceleration must be taken into account to elucidate hidden damage in the DNA molecule.

Effect of sperm DNA fragmentation on assisted reproductive technology treatment category

Objectives:To investigate the effect of sperm DNA fragmentation on outcomes of in vitro fertilization(IVF) and intracytoplasmic sperm injection(ICSI). Methods:A total of 242 cycles(154 IVF and 88 ICSI) from 235 couples were included.Sperm DNA fragmentation(SDF) and routine semen analysis were performed on the retrieval day.The rates of fertilization, embryo cleavage,good quality embryos,implantation and clinical pregnancy were measured. Results:Sperm DNA fragmentation index(DFI) in ICSI group was significantly higher than that in IVF group (P<0.01).The rates of fertilization,implantation and clinical pregnancy in ICSI were significantly higher than those in IVF with DFI≥24%(P<0.05).When DFI exceeded 24%,the OR for clinical pregnancy was 3.85(95% CI 1.40-10.59) comparing ICSI with IVF,and the OR for clinical pregnancy increased to 4.61(95%CI 1.09- 19.57) after inclusion of sperm concentration,progressively motile sperm percentage and female age as covariates. Conclusions:High DNA fragmentation might affect the outcome of ICSI and IVF.When DFI exceeds 24%, ICSI should be chosen instead of IVF.

中年男性精子DNA碎片率对体外受精-胚胎移植妊娠结局的影响

目的探讨中年男性精子DNA碎片率(DFI)与精液质量和体外受精-胚胎移植妊娠结局的关系。方法共收集180例接受常规体外受精-胚胎移植治疗且男性年龄>38岁的精液标本。根据DFI的阈值分成(<30%和≥30%)两组。主要测量指标包括:常规精液参数、激素水平、DFI、受精率、优质胚胎率、临床妊娠率等。结果通过比较分析发现,DFI与男性卵泡刺激素(FSH)、精子活力、精子形态密切相关,且精子活力随着DFI水平的升高而下降(P<0.05);当DFI≥30%时,优质胚胎率下降(P<0.05),但两组的临床妊娠率差异无显著性(P>0.05)。结论DFI可以作为中年男性精液常规分析的重要参考指标,虽然DFI影响优质胚胎率,但与辅助生殖治疗的临床妊娠结局无关。

精液优化处理后DNA碎片指数与IVF-ET胚胎质量及妊娠结局的关系

目的:评估经密度梯度离心联合上游法优化处理后的精子DNA碎片指数(DFI)与辅助生殖体外受精-胚胎移植(IVF-ET)胚胎质量及妊娠结局的关系。方法:回顾性分析2022年4月至12月在郑州大学第一附属医院生殖医学中心因单纯输卵管因素行IVF-ET的257个周期,比较男方精液优化前后精液参数和精子DFI;按优化后精子DFI将其分为高DFI组(DFI>5)与低DFI组(DFI≤5),比较两组的胚胎发育及妊娠结局;根据临床妊娠情况分为妊娠组与非妊娠组、持续妊娠组及早期流产组,比较精子DFI情况。结果:与处理前相比,精液优化处理后前向运动精子及正常形态精子百分比提高,精子DFI下降(P<0.001)。精子优化处理后高DFI组的早期流产率高于低DFI组(P<0.05)。105例临床妊娠周期中早期流产组精液优化处理前、后DFI均高于持续妊娠组(P<0.05)。结论:密度梯度离心联合上游优化处理是一种有效的精液制备方法,可提高精子前向运动能力和正常形态精子比例,降低精子DFI;优化后精子高DFI可能增加临床妊娠后早期流产的风险。

时差成像胚胎培养系统观察精子DNA碎片化指数对卵胞浆内单精子显微注射的胚胎发育及临床结局的影响

目的使用时差成像(time-lapse imagining,TLI)胚胎培养系统观察精子DNA碎片化指数(DNA fragmentation index,DFI)对卵胞浆内单精子显微注射(intracytoplasmic sperm injection,ICSI)的胚胎发育指标及临床结局的影响。方法选取2023年1月至6月在上海交通大学医学院附属国际和平妇幼保健院辅助生殖科接受ICSI技术助孕的392对夫妇为研究对象,分为常规培养组284周期和TLI组108周期,再根据DFI≤15%、>15%~<30%、≥30%进一步分为正常组、临界组、异常组。比较各组的临床资料以及临床妊娠结局。统计学方法采用t检验、单因素方差分析、χ^(2)检验或Fisher确切概率法。结果6组的女方年龄、基础促卵泡激素(follicle stimulating hormone,FSH)、身体质量指数(body mass index,BMI)及获卵数比较,差异均无统计学意义(P值均>0.05);男方精液常规指标中,浓度和正常形态率比较,差异均无统计学意义(P值均>0.05);常规正常组、常规临界组、常规异常组、TLI正常组、TLI临界组和TLI异常组的前向运动精子率分别为(46.5±16.5)%、(31.0±14.2)%、(14.8±8.4)%、(41.6±16.2)%、(32.5±14.4)%、(19.3±11.1)%,常规异常组和TLI异常组的前向运动精子率分别低于常规正常组、常规临界组、TLI正常组和TLI临界组(P值均<0.05)。6组的卵裂率和囊胚形成率比较,差异无统计学意义(P>0.05)。常规正常组、常规临界组、常规异常组、TLI正常组、TIL临界组和TLI异常组的受精率分别为(77.3±18.6)%、(78.6±17.1)%、(68.3±22.7)%、(77.4±14.5)%、(74.5±13.1)%、(63.1±25.4)%;常规异常组的受精率低于常规正常组、常规临界组、TLI正常组(P值均<0.05);TLI异常组的受精率低于常规正常组、常规临界组、TLI正常组、TLI临界组(P值均<0.05)。常规正常组、常规临界组、常规异常组的妊娠率分别为57.4%(39/68)、54.5%(24/44)、27.3%(6/22),异常组低于正常组和临界组(P值均<0.05)。TLI正常组、TLI临界组和TLI异常组3组的妊娠率比较,差异无统计学意义(P>0.05)。常规组3组之间以及TLI 3组之间的早期流产率比较,差异无统计学意义(P>0.05)。结论精子DFI值的升高会影响精子前向运动率,还会影响胚胎的受精率,高DFI精子进行ICSI助孕时使用TLI胚胎培养系统可以获得稳定的妊娠率。

基于氧化应激效应探讨精索静脉曲张患者显微结扎术对精子DNA碎片及试管婴儿临床结局的影响指数

目的:探讨精索静脉显微结扎术对精索静脉曲张(VC)患者精子DNA碎片指数(DFI)及临床结局的影响。方法:选取VC伴有精子DNA碎片异常并行辅助生殖技术治疗的患者80例,按照随机数字表法分成观察组和对照组,每组40例。观察组行精索静脉显微结扎术,术后联合左卡尼汀口服溶液治疗;对照组单纯采用左卡尼汀口服溶液治疗。疗程3个月。治疗后,观察两组患者精子DNA碎片指数(DFI)、精子浓度、前向运动精子百分比(PR)及临床结局指标的变化。结果:治疗后,观察组总有效率高于对照组(P<0.05);观察组DNA碎片指数明显低于对照组(P<0.05),观察组精子浓度、PR明显高于对照组(P<0.01)。观察组受精率、卵裂率、优质胚胎率、养囊成功率及妊娠率均高于对照组(P<0.05)。结论:精索静脉曲张结扎术后联合左卡尼汀口服溶液能明显改善精索静脉曲张患者的精子质量,同时能修复患者精子DNA的完整结构,对体外受精(IVF)的临床结局有促进作用,疗效优于单纯运用左卡尼汀口服溶液治疗。

Obesity leads to higher risk of sperm DNA damage in infertile patients

There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index （BMI）. A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling （TUNEL） assay, we observed an increased rate of sDerm DNA damage in obese men （odds ratio （95% confidence interval）： 2.5 （1.2-5.1））.

Sperm nuclear histone H2B： correlation with sperm DNA denaturation and DNA stainability

Aim： To examine the relationship between sperm DNA damage and sperm nuclear histone （H2B） staining. Methods： We evaluated sperm samples from 14 consecutive asthenoteratozoospermic infertile men and six consecutive fertile controls. Sperm nuclear histone （H2B） staining and sperm chromatin integrity （assessed by sperm chromatin structure assay and expressed using the percentage of （i） DNA fragmentation index [%DFI] and （ii） high DNA stainability [%HDS）]） were evaluated. Results： Histone H2B immunocytochemistry demonstrated two nuclear staining patterns： （i） focal punctate staining; and （ii） diffuse staining. Infertile men had a higher mean percentage of spermatozoa exhibiting diffuse H2B staining than did fertile men （7.7%± 4.6% vs. 1.6% ±1.2%, respectively, P 〈 0.01）. We observed significant relationships between the proportion of spermatozoa with diffuse nuclear histone staining and both sperm %DFI （r = 0.63, P 〈 0.01） and sperm %HDS （r = 0.63, P 〈 0.01）. Conclusion： The data demonstrate that infertile men have a higher proportion of spermatozoa with diffuse histone H2B than do fertile men and suggest that sperm DNA damage might, at least in part, be due to abnormally high histone H2B levels.

The ability of sperm selection techniques to remove single- or double-strand DNA damage

A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are densitygradient centrifugation （DGC） and swim-up （SUP）. To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques （ART）, but they may have negative effects on sperm DNA. In this study, the ability of these semen processing techniques to eliminate spermatozoa containing single- and double-strand DNA damage was assessed by the two-tailed comet assay and the sperm chromatin dispersion test in 157 semen samples from patients seeking assisted reproduction treatment. Our results indicated that SUP and DGC are equally efficient in eliminating spermatozoa containing double-strand DNA damage and sperm with highly damaged （degraded） DNA, as characterized by the presence of both single- and double-strand DNA breaks. However, DGC is more efficient than SUP in selecting spermatozoa that are free from single-strand DNA damage. Future studies should characterise the importance of the various types of DNA damage and examine the sperm processing protocols used in each laboratory to determine their ability to eliminate DNA damage and hence, prevent the potential transmission of genetic mutations via ART.

No difference in high-magnification morphology and hyaluronic acid binding in the selection of euploid spermatozoa with intact DNA

In this study, we compared conventional sperm selection with high-magnification morphology based on the motile sperm organellar morphology examination （MSOME） criteria, and hyaluronic acid （HA） binding for sperm chromosome aneuploidy and DNA fragmentation rates. Semen from 50 severe male factor cases was processed through density gradient centrifugation, and subjected to sperm selection by using the conventional method （control）, high magnification at x6650 or HA binding. Aneuploidy was detected by fluorescence in situ hybridization with probes for chromosomes 13, 18, 21, X and Y, and DNA fragmentation by the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） method. Spermatozoa selected under high-magnification had a lower DNA fragmentation rate （2.6% vs. 1.7%; P=0.032）, with no significant difference in aneuploidy rate （0.8% vs0.7%; P=0.583）, than those selected by the HA binding method. Spermatozoa selected by both methods had much lower aneuploidy and DNA fragmentation rate than the controls （7% aneuploidy and 26.8% DNA fragmentation rates, respectively）. In the high-magnification group, the aneuploidy rate was lower when the best spermatozoa were selected than when only the second-best spermatozoa were available for selection, but the DNA fragmentation rate was not different. In conclusion, sperm selection under high magnification was more effective than under HA binding in selecting spermatozoa with low DNA fragmentation rate, but the small difference （0.9%） might not be clinically meaningful. Both methods were better than the conventional method of sperm selection.

精子DNA碎片率与年龄、精液参数和生活习惯相关性分析

目的分析男性精子DNA碎片率(DFI)与年龄、精液参数和生活习惯相关性。方法选择405例患者进行一般描述性分析、回归分析,观察有无统计学意义。结果主要体现在年龄与精子DFI呈正向相关、雌二醇和精子DFI负相关(P<0.05)。不抽烟不喝酒与精子DFI负相关(P<0.05)。结论男性年龄、生殖激素水平、生活习惯与精子DFI有相关性。生活习惯或许是造成男性生育力下降的因素之一,但是其分子机理以及损伤机制仍然需要通过进一步的体内外实验进行证实。此外,考虑到当前实验在选择研究对象时可能存在未有效鉴别和剔除其他可变因素的情况,本研究尚需进行进一步大样本量对实验进行验证。

精子DNA碎片对体外受精-胚胎移植妊娠结局及胚胎发育的影响

目的:分析精子DNA碎片指数(DFI)对体外受精-新鲜胚胎移植(IVF-ET)助孕及活产结局的影响。方法:选取2015年6月至2020年12月因女方因素首次行IVF并进行新鲜胚胎移植的患者共947例,根据DFI分为低、中、高3组:DFI<15%、15≤DFI≤30%和30%<DFI,比较3组双方基础数据,女方包括年龄、体质量指数(BMI)、基础生殖激素、AMH等;男方包括年龄、BMI、精液参数;超促排卵参数;处理前和处理后IVF精液参数;促排卵结局、胚胎质量及妊娠结局。结果:不同DFI水平间相比,双方年龄在3组间均有显著性差异,15≤DFI≤30%和30%<DFI组双方年龄显著大于DFI<15%组;基础状态精液参数中前向运动精子百分率、非前向运动精子百分率、不活动精子百分率,以及IVF处理前精子总活率、前向运动精子百分率在3组间也均有显著差异(P<0.01);中和高DFI组中基础精子正常形态率、IVF处理前精子浓度、精子总数和处理后精子浓度均显著低于低DFI组;30%<DFI组无论是精液处理前还是精液处理后精子总数均显著低于其他两组(P<0.01)。此外,中和高DFI组受精率显著低于低DFI组,其他临床数据包括促排卵参数、胚胎质量、妊娠结局组间均无显著差异。结论:高DFI水平对精子活率产生显著影响,IVF精液处理后DFI水平与精子浓度、精子总数、受精率均呈显著负相关,对胚胎质量及妊娠结局无影响。

不育患者精子DNA碎片指数、血清25-羟化维生素D与精液常规参数的相关性分析

目的 探讨男性不育患者精子DNA碎片指数(DFI)、血清25-羟化维生素D [25(OH)VD]总量与精液常规参数的相关性。方法 回顾性分析2021年11月至2022年7月在空军军医大学第一附属医院生殖医学中心就诊的627名男性不育患者的检查数据,采用计算机辅助精子分析系统分析精液常规参数,手工法检测正常形态精子百分率,流式细胞仪分析精子DFI,液相色谱-串联质谱检测系统检测血清25(OH)VD总量,采用SPSS 25.0数据分析软件分析精子DFI与精子总数、浓度、前向运动率(PR)、总活动率、正常形态精子百分率的相关性,以及血清25(OH)VD总量与精子总数、浓度、PR、总活动率、正常形态精子百分率、精子DFI的相关性。结果 精子DFI与精子总数、浓度呈负相关,但其相关系数绝对值均<0.1,临床价值较小(r=-0.082、-0.094,P均<0.05),与精子PR、总活动率、正常形态精子百分率呈负相关(r=-0.519、-0.534、-0.327,P均<0.001),差异均具有统计学意义;血清25(OH)VD总量与精子总数、浓度、PR、总活动率无相关性(r=-0.009、-0.020、0.059、0.054,P>0.05),与正常形态精子百分率呈正相关(r=0.147,P<0.001),与精子DFI呈负相关(r=-0.294,P<0.001),差异均具有统计学意义。结论 精子DFI与精子PR、总活动率、正常形态精子百分率呈明显负相关,可以在一定程度上反映精子质量,精子DFI检测与精液常规参数可以互为补充,为全面、客观评估男性生育力提供有效信息;血清25(OH)VD总量与正常形态精子百分率呈正相关,与精子DFI呈负相关,可作为评估男性生育力的参考指标。