Correlation analysis of sperm DNA fragmentation index with semen parameters and the effect of sperm DFI on outcomes of ART

Meta-correlation of Sperm Morphology and DNA Fragmentation Index

The 6th WHO guidelines for human semen examination recommend advanced semen analysis, such as the sperm DNA fragmentation index (DFI), to evaluate male factor infertility, as oxidative stress in the male reproductive system can damage sperm plasma membranes and compromise DNA integrity. Although sperm DFI was known to be associated with pregnancy probability, its examination is often limited by unavailability and high costs. In contrast, basic semen analysis, which includes sperm morphology assessment, is routinely performed, widely available, and cosf-effective. This systematic review and meta-analysis aimed to evaluate the correlation between sperm morphology and DNA Fragmentation Index (DFI) to improve diagnostic and clinical applications. Relevant studies were retrieved from MedLine, Web of Science, Scopus, EBSCO, and ProQuest, using keywords related to the correlation between sperm morphology and DFI. Correlation analyses were conducted using a random-effects model to calculate r-values for normal and abnormal sperm morphology with DFI. This meta-analysis showed an inverse correlation between normal sperm morphology and DFI with r: -0.30 and a positive correlation between abnormal sperm morphology and DFI with r: 0.39. Specifically, the head deformities had stronger correlation with DFI compared to neck and tail deformities. This study underscores the potential to predict DFI from sperm morphology results in settings where DFI testing is unavailable.

Relationship between seminal plasma trace elements and sperm quality

Male fertility has declined recently, mainly due to reduced sperm quality. While common factors contribute to this issue, they do not adequately explain all cases. Environmental pollutants, especially trace elements, significantly affect sperm quality, but the link between trace element exposure in seminal plasma and male fertility decline is still poorly understood. Here, inductively coupled plasma mass spectrometry was employed to detect 25 trace elements in seminal plasma from 209 Chinese men of reproductive age. The study utilized logistic regression and restricted cubic splines to examine the relationship between specific trace elements and semen parameters across different groups. Group comparisons revealed that the concentrations of Mg, Ca, Fe, Cu, Zn, Mn, Sr, Cd, and Co were significantly higher in patients with asthenozoospermia. The concentration of Mo was significantly lower in patients with teratozoospermia. Notably, the trace element exposure levels in patients with oligozoospermia were comparable to those of healthy individuals. Additionally, correlation analyses indicated that Mg, Ca, Fe, Zn, As, and Cd levels positively correlated with sperm DFI. Furthermore, significant positive correlations were identified between the Mg, Fe, Zn, and Tl concentrations and sperm concentration. Low Cu, Mn, and Co levels positively correlated with sperm concentration. Mg, Zn, Cd, and low concentrations of Co were negatively correlated with sperm motility. This study presents the largest-scale profile of trace element exposure in seminal plasma to date, emphasizing the significance of seminal trace elements as biomarkers that accurately reflect the environmental exposure levels of male germ cells. Our findings suggest that increased trace elements, particularly metal elements, in seminal plasma primarily reduce sperm motility rather than affecting sperm concentration or morphology. Further studies are needed to explore the biological mechanisms that link seminal trace elements to male fertility decline.

The Nexus Between Sperm Membrane Integrity, Sperm Motility, and DNA Fragmentation

This study investigated the interrelationships between sperm plasma membrane integrity, motility, and DNA fragmentation (SDF) to provide a more holistic understanding of male fertility. A total of 1159 ejaculates were analyzed for sperm membrane integrity (% dead spermatozoa), motility (% immotile spermatozoa), and SDF (% sperm with fragmented DNA). The statistical methods included non-parametric correlation analysis and artificial intelligence (AI)-generated cluster analysis to identify patterns based on these three parameters. The results showed a moderate correlation (ρ = 0.65; p < 0.000) between sperm membrane integrity and motility, indicating that immotile sperm were more likely to exhibit membrane damage. A weak correlation (ρ = 0.21; p < 0.000) suggested that DNA damage was largely independent of the other sperm parameters. Cluster analysis identified three main clusters: Cluster 0: high levels of low membrane integrity, immotile sperm, and moderate DNA fragmentation. Cluster 1: moderate membrane integrity and motility but extremely high DNA fragmentation. Cluster 2: the lowest levels of membrane damage, immotile sperm, and DNA fragmentation, indicating overall better sperm quality. The clustering techniques demonstrated their ability to integrate multiple sperm parameters, enabling a more individualized fertility diagnosis and potentially enhancing male infertility assessments.

Abnormal sperm tails correlate with the sperm DNA fragmentation index, irrespective of progressive motility, according to an analysis of 5125 semen reports

PURPOSE

Sperm progressive motility (PR) is correlated with the sperm DNA fragmentation index (SDF). Moreover, abnormalities in sperm tails are closely associated with the quality of sperm PR. However, the correlation of abnormal sperm tails with the SDF remains unknown.

METHODS

Routine semen examination was performed according to the World Health Organization guidelines with a computer-assisted semen analysis system. SDF analysis was conducted via the sperm chromatin structure assay method. Spearman correlation was used to test the correlation of the SDF with age and conventional semen parameters. The relationship between the SDF and abnormal tails was explored by binary logistic regression analysis, restricted cubic spline (RCS) analyses and subgroup analysis. ROC curves were used to assess the predictive capacity of age, abnormal tails and PR for the SDF.

RESULTS

The SDF was associated with sperm morphology, with a significant correlation observed with abnormal sperm tails (r = 0.491, P < 0.001). Binary regression analysis revealed that abnormal sperm tails were an independent influencing factor of the SDF. RCS analyses and Trend analysis suggested that as the number of abnormal sperm tails increased, the risk of an abnormal SDF also increased, and the trend was statistically significant (P for trend < 0.001). The ROC curve demonstrated that abnormal sperm tails had good discriminatory ability for the SDF (AUC: 0.757, P < 0.001).

CONCLUSION

Abnormal sperm tails are an independent influencing factor of the SDF, and a higher number of abnormal tails is associated with an increased risk of an abnormal SDF.

A novel biosensor for highly sensitive DNA damage detection using TdT and CRISPR-Cas12a

This study presents a highly sensitive fluorescence biosensor integrating TdT enzyme and CRISPR-Cas12a for precise detection of sperm DNA damage, achieving a detection limit of 0.99 pM and a linear range of 0.001-0.2 nM. Its exceptional sensitivity, simplicity, and versatility make it a transformative tool for reproductive medicine and clinical diagnostics.

Paternal Effects in Mammalian Reproduction: Functional, Environmental, and Clinical Relevance of Sperm Components in Early Embryos and Beyond

In addition to widely recognized contributions of the paternal genome, centriole, and oocyte-activation factors, sperm deliver a wide range of macromolecules to the fertilized embryo. The impacts of these factors on the embryo, progeny, and even subsequent generations have become increasingly apparent, along with an understanding of an extensive potential for male health and environmental exposures to exert both immediate and long-term impacts on mammalian reproduction. Available data reveal that sperm factors interact with and regulate the actions of oocyte factors as well as exerting additional direct effects on the early embryo. This review provides a summary of the nature and mechanisms of paternal effects in early mammalian embryos, long-term effects in progeny, susceptibility of sperm components to diverse environmental factors, and potential approaches to mitigate adverse effects of such exposures.

B cell translocation gene 2 expression levels in human granulosa cells is negatively associated with in vitro fertilization/intracytoplasmic sperm injection outcomes: a pilot study

PURPOSE

This study aimed to monitor the expression of B-cell translocation gene 2 (BTG2) in granulosa cells of patients undergoing IVF/ICSI with respect blastocyst quality outcomes.

METHODS

We recruited 181 women undergoing IVF/ICSI cycles for infertility. Granulosa cells were extracted from follicular fluid. BTG2 expression level of granulosa cells were stratified into tertiles (low, middle, and high), and the patients of each tertile were compared for outcome indicators by Kruskal-Wallis analysis. Spearman's correlation analyses were used to evaluate the correlation between BTG2 mRNA levels and outcome indicators. Generalized linear models and generalized additive models with smoothing splines were used to adjust for potential confounders.

RESULTS

Patients in the low BTG2 tertile had higher oocyte retrieval, fertilization, blastocyst formation, and high-quality blastocyst rates than those in the high BTG2 tertile. Patients in the high BTG2 tertile exhibited a downward trend in implantation and clinical pregnancy rates compared to those in the low or middle BTG2 tertiles, whereas the early pregnancy loss rate showed an upward trend, although the difference was not significant. After adjusting for confounding factors, the expression level of BTG2 was negatively correlated with oocyte retrieval, blastocyst formation, and high-quality blastocyst rates. Stratified analysis of AMH > 4 ng/ml showed elevated BTG2 expression was associated with reduced oocyte retrieval, fertilization, cleavage, blastocyst formation, and high-quality blastocyst rates. No differences in these outcomes were observed in patients with AMH ≤ 4 ng/ml.

CONCLUSION

In women with high AMH levels (> 4 ng/ml) elevated BTG2 expression in granulosa cells was associated with poor quality blastocyst outcomes.

Sperm DNA fragmentation index: limited effectiveness on predicting embryo quality in assisted reproduction technology treatments

PURPOSE

Prior sperm DNA fragmentation index (DFI) thresholds for diagnosing male infertility and predicting assisted reproduction technology (ART) outcomes fluctuated between 15 and 30%, with no agreed standard. This study aimed to evaluate the impact of the sperm DFI on early embryonic development during ART treatments and establish appropriate DFI cut-off values.

METHODS

Retrospectively analyzed 913 couple's ART cycles from 2021 to 2022, encompassing 1,476 IVF and 295 ICSI cycles, following strict criteria. The WHO guidelines directed the semen analysis, while the acridine orange test (AOT) determined the DFI. Male factors (age, BMI, DFI, infertility duration, sperm parameters) and female parameters (age, BMI, AMH, retrieved oocytes) were evaluated. We also assessed embryological parameters like fertilization rate, cleavage rate, and blastocyst quality. Correlations between DFI and embryo quality were examined and DFI cut-off values were established using ROC analysis.

RESULTS

The Sperm DFI demonstrated a positive correlation with male age and a negative correlation with sperm motility, concentration, and normal morphology, while showing no relation to BMI. No connection between DFI and embryological parameters in only IVF and ICSI groups was found, but a negative correlation with fertilization rate was seen in all ART cycles. ROC curve analysis revealed a DFI cut-off value of 21.15% having 36.7% sensitivity and 28.9% specificity in predicting high fertilization rate (≥ 80%).

CONCLUSION

Sperm DFI had a negative correlation with fertilization rate, but limited predictive efficacy and no significant link to other embryological parameters. DFI assessments may improve early embryo development prediction during ART treatments, particularly in older males or those exhibiting poor sperm quality.

Association between sperm DNA fragmentation index and recurrent pregnancy loss: results from 1485 participants undergoing fertility evaluation

Objective

Several male factors have been reported to play a role in recurrent pregnancy loss (RPL). The aim of this study is to explore the relationship between semen parameters, sperm DNA fragmentation index (DFI) and RPL.

Method

A total of 1485 participants were recruited from a university hospital between April 2020 and August 2022. Six hundred and thirtyfour men from couples with RPL were assigned to the case group, while 851 men from couple without RPL who underwent fertile evaluation were assigned to the control group. Semen parameters including sperm DNA fragmentation, were assessed.

Results

No statistically significant differences in semen parameters, sperm kinematics and DFI were observed between the case group and the control group. A higher proportion of men in the case group had a DFI > 30% compared to those in the control group; however, this difference was not statistically significant. Restricted cubic spline analysis revealed no significant non-linear relationships between continuous DFI and risk of RPL.

Conclusion

Our study indicates that there is no significant relationship between DFI and RPL risk. Further prospective studies are needed to explore the impact of DFI on fertility outcomes in couples experiencing RPL.

Heterozygous mutation in BRCA2 induces accelerated age-dependent decline in sperm quality with male subfertility in rats

Tumor suppressor BRCA2 executes homologous recombination to repair DNA double-strand breaks in collaboration with RAD51, involving exon 11 and 27. Exon 11 constitutes a region where pathogenic variants (PVs) accumulate, and mutations in this region are known to contribute to carcinogenesis. However, the impact of the heterozygous PVs of BRCA2 exon 11 on the life quality beyond cancer risk, including male fertility, remains unclear. Here, we established a rat model with a frameshift on the seventh BRC repeat in Brca2 exon 11 (Brca2+/p.T1942fs), which is homologous to human BRCA2+/p.T1974fs, using CRISPR/Cas9 system. Our analyses revealed that the heterozygous rats with the PV in the BRCA2 exon 11 showed increased DNA double-strand breaks and apoptosis in spermatogonia and spermatocytes, accelerated testicular germ cell loss, and deterioration in sperm quality according with aging, ultimately resulting in early male reproductive dysfunction. Of note, these alterations in testes and sperm, including DNA fragmentation in spermatozoa, were observed from completion of sexual maturation. The present findings suggest that it is crucial to consider not only cancer risk but also potential declines in reproductive capacity in men carrying BRCA2 exon 11 PVs. Further investigation is warranted to determine whether similar traits appear in humans.

Correlation between standard sperm parameters and sperm DNA fragmentation from 11,339 samples

Conventional semen parameters have long been considered fundamental in male fertility analyses. However, doubts have been raised regarding the clinical utility of the assessment of spermatozoa (sperm) DNA damage. In this retrospective study, we investigated the potential correlation between conventional semen parameters and semen DNA fragmentation (SDF) assessed as sperm DNA damage, in 11,339 semen samples collected between January 2019 and June 2022. We observed significant negative correlations between the DNA fragmentation index (DFI) and sperm viability (correlation coefficient [r] = -0.514) as well as progressive sperm motility (r = -0.512, p < 0.05). Samples were categorized into three groups according to DFI levels (Groups A, B, and C: ≤15%, 15 < DFI ≤30%, and >30%, respectively). Furthermore, the percentage of semen samples with normal sperm conventional parameters in Groups A, B, and C was 76.7% (4369/5697), 61.4% (2351/3827), and 39.7% (721/1815), respectively. Moreover, according to the reference values of conventional sperm parameters, the samples were divided into Groups F, G, and H with all normal, only one abnormal, and > two abnormal parameters, respectively. In addition, the proportions of samples with abnormal DFI values (>30) in Groups F, G, and H were 9.7% (721/7441), 23.1% (618/2676), and 39.0% (476/1222), respectively. Multivariate logistic regression models demonstrated that sperm vitality, progressive sperm motility, normal sperm form, total sperm count, semen volume, age, and some sperm kinematics collectively improved the area under the receiver operating characteristic curve (AUROC) to 0.861, surpassing the predictive value of a single predictor of pathologically damaged sperm DNA. Our study suggests that samples with abnormal sperm parameters may have a higher likelihood of high DNA fragmentation. Furthermore, certain semen parameters could be potential indicators of sperm DNA fragmentation, aiding sperm selection in assisted reproductive procedures.

Antioxidant Genes Variants and Their Association with Sperm DNA Fragmentation

Semen possesses a variety of antioxidant defense mechanisms which protect sperm DNA from the damaging effects of oxidative stress. Correlation between antioxidant genes variants and sperm DNA fragmentation (SDF) level is not sufficiently studied. Therefore, we investigated the association between several single nucleotide polymorphisms (SNPs): CYP1A1 (rs1048943A > G), CYP4F2 (rs2108622G > A), NRF2 (rs6721961C > A), PON1 (rs662A > G), NOS3 (rs1799983G > T), GSTM1 (null), CAT (rs1001179C > T), SOD2 (rs4880A > G), GSTP1 (rs1695A > G), PON2 (rs7493G > C), EPHX2 (rs1042064T > C), and AHR (rs2066853G > A) and elevated SDF. The study employed a case-control design where, the allele and genotype frequencies of the selected SNPs were compared between 75 semen samples with abnormal SDF (the cases) and 75 samples with normal SDF (the controls). DNA was extracted from the semen samples and allele-specific PCR (AS-PCR) was used for genotyping the SNPs. Relevant data were collected from the patients' records et al.-Basma Fertility Center. Suitable statistical tests and multifactorial dimensionality reduction (MDR) test were used to anticipate SNP-SNP interactions. Comparison of semen parameters revealed significant differences between cases and controls in terms of liquefaction time, sperm total motility, and normal form. Genotype frequencies of NOS3 G > T (GT), SOD2 A > G (AA and AG), EPHX2 T > C (CC and CT), and AHR G > A (GA and GG) were significantly different between cases and controls. Allele frequencies of SOD2 (G-allele), and EPHX2 (T-allele) also significantly varied between cases and controls. MDR analysis revealed that the NOS3, SOD2, and EPHX2 SNPs combination has the highest impact on SDF. The study findings suggest that genetic variations in genes involved antioxidant defenses contribute to abnormal SDF.

Comparison of Cholesterol Carriers and Substitution of Fructose and Glycerol With Trehalose on Frozen/Thawed ATP Content, DNA Integrity and Kinematics Variables of Ram Spermatozoa

Current study was aimed to assess the β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD) on delivery of cholesterol, and substitution of fructose and glycerol with trehalose on the ram semen cryosurvival. Samples were collected, diluted with Tris-citric acid-LDL extender, pooled, and used. In experiment I, βCD and MβCD carriers were used and compared to deliver the cholesterol (at 0, 0.5, 1, 1.5, 2, and 4 mg/mL). In the experiment II, trehalose (0, 7, 14, 21, and 28 mM) was substituted with fructose (28, 21, 14, 7, 0 mM, respectively). In the experiment III, the best cholesterol/carrier dose groups from the first experiment, were selected to be evaluated with the fructose/trehalose (14/14 mM) combination compared to fructose (28 mM) alone. The concentration of glycerol in the above-mentioned experiments was set at 4.5%. In the experiment IV, the effect of lowering glycerol (4% vs. 4.5%) was assessed using selected cholesterol/carrier groups. Kinematics, chromatin integrity, ATP contents, malondialdehyde amounts and viability were evaluated. Cholesterol (especially at 1.5 and 2 mg/mL) improved the kinematics and ATP levels using both carriers. The optimised amounts of trehalose (14 mM)/fructose(14 mM) reduced peroxidation and DNA fragmentation levels. Co-administration of optimised levels of cholesterol with trehalose/fructose did not show extra beneficial effects compared to each of them. Trehalose could not protect the spermatozoa at lower amounts of glycerol (4% vs. 4.5%). In conclusion, either the optimised levels of cholesterol (using βCD or MβCD carriers) or substitution of half of the fructose with the trehalose alone could lead to improvement in quality of frozen/thawed ram semen.

Association of lifestyle and occupational exposure factors with human semen quality: a cross-sectional study of 1060 participants

The incidence of male infertility (MI) is rising annually. However, the lifestyle and occupational exposure factors contributing to MI remain incompletely understood. This study explored the effects of self-reported lifestyle and occupational exposure factors on semen quality. Among 1060 subjects invited to participate, 826 were eligible. The participants' general characteristics, lifestyle, and occupational exposure factors were collected immediately before or after semen evaluation through an online questionnaire. Initially, univariate analysis was used to investigate the relationship between the abovementioned factors and semen quality. The results indicated significant associations between low semen quality and various factors, including age, BMI, infertility type and duration, abstinence time, semen and sperm parameters, smoking, alcohol consumption, irregular sleep habits, and frequent exposure to high temperatures and chemicals at work (p < 0.05). Then, multivariate analysis was conducted to identify factors independently associated with low semen quality. Adjustment for relevant confounders was achieved by including factors with a p-value < 0.25 from univariate analyses as covariates in the binomial and ordered logistic regression models. The results suggested that alcohol consumption was a positive factor for sperm concentration (odds ratio [OR] = 0.60; 95% confidence interval [CI] = 0.36-0.99; p = 0.045). The groups with a BMI ≥ 24 and <28 kg/m2 showed a significant decrease in sperm progressive motility when compared to the reference group (BMI < 24 kg/m2) (OR = 0.63; 95% CI = 0.46-0.87, p = 0.005). In addition, the groups that drank green tea <1 time/week (OR = 1.52, 95% CI = 1.05-2.2) and 1-4 times/week (OR = 1.61, 95% CI = 1.02-2.54) exhibited significantly increased sperm DFI values compared with the group that drank green tea 5-7 times/week. In conclusion, these findings underscore the importance of maintaining a normal weight and regularly consuming green tea for men.

DNA breakpoints and free DNA fragments as potential predictors of infertility

The study investigated the impact of varicocele on male infertility by analyzing sperm samples from 42 varicocele patients and 22 healthy individuals. Basic sperm parameters such as concentration and vitality were assessed, along with the DNA Fragmentation Index (DFI) using the SCSA method. Additionally, the mean number of sperm DNA breaks (MDB) and free DNA fragments amount in seminal plasma (fDFA) were analyzed using the TDT-Strand Displacement Probe Technique. Results showed higher levels of DFI, MDB, and fDFA in varicocele-related infertility cases. Combining MDB and fDFA proved more effective in predicting fertility compared to individual assessments or the DFI alone. While these findings suggest a potential role for MDB and fDFA as predictors of male fertility, further rigorous studies are needed to validate their application in varicocele-related male infertility.

Assessing the efficacy of a novel sperm-washing medium enriched with serotonin, L-carnitine, and coenzyme Q10: an observational cohort study

ABSTRACT

This observational cohort study investigated the potential of a novel sperm-washing medium (SWM) enriched with serotonin (5-HT), L-carnitine (L-C), and coenzyme Q10 (CoQ10) to enhance sperm motility and reduce DNA damage. It compared this innovative medium (5-HT/L-C/CoQ10 SWM) with two widely used commercial media (SWM 1 and SWM 2). Ninety-eight volunteers from an infertility clinic provided semen samples, which were divided into three aliquots for analysis in different SWMs: group 1, SWM was composed of hydroxyethyl piperazineethanesulfonic acid (HEPES), sodium bicarbonate, human serum albumin (HSA), taurine, and gentamicin sulfate (SWM 1); group 2, SWM was composed of HEPES, sodium bicarbonate, and HSA (SWM 2); and group 3, SWM was composed of HEPES-buffered human tubal fluid supplemented with 5-HT, L-C, and CoQ10 (5-HT/L-C/CoQ10 SWM). Sperm motility was categorized as progressive, nonprogressive, or immotile. Apoptosis, reactive oxygen species (ROS) production, and DNA fragmentation were also assessed. There were no significant differences in total or progressive sperm motility among the groups. Spermatozoa in group 3 exhibited reduced apoptosis, necrosis, and ROS levels and increased viability. No significant differences were observed in the DNA fragmentation index among groups. The 5-HT/L-C/CoQ10 SWM reduced sperm oxidative stress and apoptosis compared with those of the two commercially available SWMs, suggesting that 5-HT/L-C/CoQ10 SWM could be useful for enhancing in vitro fertilization success rates.

Reliable Detection of Excessive Sperm Ros Production in Subfertile Patients: How Many Men with Oxidative Stress?

Sperm oxidative stress has been extensively associated to male infertility. However, tests to detect this parameter have not been yet introduced in clinical practice and no definitive data are present on the extent of oxidative stress in male infertility. In this study, we used a novel and reliable flow cytometric method to reveal sperm ROS production in subfertile patients (n = 131) and in healthy donors (n = 31). Oxidative stress was higher in subfertile patients (14.22 [10.21-22.08]%) than in healthy donors (9.75 [8.00-14.90]% (p < 0.01)), but no correlation was found with age, semen quality or sDF. We also failed to detect an increase in sperm ROS production with semen viscosity or leukocytospermia, but a sharp impact of semen bacteria was evident (with bacteria: 31.61 [14.08-46.78]% vs. without bacteria: 14.20 [10.12-22.00]%, p < 0.01). Finally, after establishing a threshold as the 95th percentile in healthy donors, we found that 29% of subfertile patients exceeded this threshold. The percentage decreased to 25.56% when we excluded subjects with bacteriospermia and increased to 60.87% when only these patients were considered. In conclusion, 29% of subfertile patients showed an excessive sperm ROS production. Surprisingly, this parameter appears to be independent from routine semen analysis and even sDF determination, promising to provide additional information on male infertility.

Elucidating the impact of Y chromosome microdeletions and altered gene expression on male fertility in assisted reproduction

BACKGROUND

Genetic abnormalities like Y chromosome microdeletions are implicated in male infertility. This study investigated the association of azoospermia factor (AZF) region microdeletions with unsuccessful assisted reproductive techniques (ART), including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

METHODS

This cross-sectional analysis study examined 80 Iranian oligospermic men (mean age 34 years) with prior failed ICSI and IVF cycles (IR.IAU.TNB.REC.1401.041). Semen analysis evaluated quantity/quality parameters based on World Health Organization guidelines. Participants were stratified by sperm DNA fragmentation (SDF) levels into: control (SDF < 15%, n = 20), mild elevation (15% ≤ SDF ≤ 30%, n = 60), and high (SDF > 30%, n = 20). Multiplex PCR mapped AZF microdeletions in the high SDF group. The AZF-associated genes were selected by RNA Seq analysis, and the candidate genes were checked for expression level by real-time PCR.

RESULTS

High SDF individuals exhibited poorer semen metrics, including 69% lower sperm concentration (P = 0.04) than those without SDF. Of this subset, 45% (9/20 men) harboured predominately AZF microdeletions. Men with AZF microdeletions showed higher SDF (32% vs 21%, P = 0.02) and altered AZF-associated genes expression. As USP9Y 3-fold, UTY 1.3-fold, and BPY2 1-fold revealed up-regulation, while IQCF1 8-fold, CDY 6.5-fold, DAZ 6-fold, and DDX3Y 1-fold underwent down-regulation. The PAWP gene was also down-regulated (5.7-fold, P = 0.029) in the IVF/ICSI failure group.

CONCLUSION

AZF microdeletions significantly impact male infertility and ART outcomes. High SDF individuals exhibited poorer semen metrics, with 45% AZF microdeletions. These microdeletions altered AZF-associated genes expression, affecting fertility mediator PAWP independently. Dual AZF and SDF screening enables personalized management in severe male infertility, potentially explaining IVF/ICSI failures.

Optimized sperm selection: a highly efficient device for the isolation of progressive motile sperm with low DNA fragmentation index

PURPOSE

To identify the sperm preparation procedure that selects the best sperm population for medically assisted reproduction.

METHODS

Prospective observational study comparing the effect of four different sperm selection procedures on various semen parameters. Unused raw semen after routine diagnostic analysis was split in four fractions and processed by four different methods: (1) density gradient centrifugation (DGC), (2) sperm wash (SW), (3) DGC followed by magnetic activated cell sorting (MACS), and (4) using a sperm separation device (SSD). Each fraction was analyzed for progressive motility, morphology, acrosome index (AI), and DNA fragmentation index (DFI).

RESULTS

With DGC as standard of care in intraclass correlation coefficient analysis, only SSD was in strong disagreement regarding progressive motility and DFI [0.26, 95%CI (- 0.2, 0.58), and 0.17, 95%CI (- 0.19, 0.45), respectively]. When controlling for abstinence duration, DFI was significantly lower after both MACS and SSD compared to DGC [- 0.27%, 95%CI (- 0.47, - 0.06), p = 0.01, and - 0.6%, 95%CI (- 0.80, - 0.41), p < 0.001, respectively]. Further comparisons between SSD and MACS indicate significantly less apoptotic cells [Median (IQR) 4 (5), 95%CI (4.1, - 6.8) vs Median (IQR) 5 (8), 95%CI (4.9, - 9.2), p < 0.001, respectively] and dead cells [Median (IQR) 9.5 (23.3), 95%CI (13.2, - 22.4) vs Median (IQR) 22 (28), 95%CI (23.1, - 36.8), p < 0.001, respectively] in the SSD group.

CONCLUSION

The selection of a population of highly motile spermatozoa with less damaged DNA from unprocessed semen is ideally performed with SSD. Question remains whether this method improves the embryological outcomes in the IVF laboratory.

Emerging trends in sperm selection: enhancing success rates in assisted reproduction

This comprehensive review explores the evolving landscape of sperm selection techniques within the realm of Assisted Reproductive Technology (ART). Our analysis delves into a range of methods from traditional approaches like density gradient centrifugation to advanced techniques such as Magnetic-Activated Cell Sorting (MACS) and Intracytoplasmic Morphologically Selected Sperm Injection (IMSI). We critically assess the efficacy of these methods in terms of sperm motility, morphology, DNA integrity, and other functional attributes, providing a detailed comparison of their clinical outcomes. We highlight the transition from conventional sperm selection methods, which primarily focus on physical characteristics, to more sophisticated techniques that offer a comprehensive evaluation of sperm molecular properties. This shift not only promises enhanced prediction of fertilization success but also has significant implications for improving embryo quality and increasing the chances of live birth. By synthesizing various studies and research papers, we present an in-depth analysis of the predictability of different sperm selection procedures in ART. The review also discusses the clinical applicability of these methods, emphasizing their potential in shaping the future of assisted reproduction. Our findings suggest that the integration of advanced sperm selection strategies in ART could lead to more cost-effective treatments with reduced duration and higher success rates. This review aims to provide clinicians and researchers in reproductive medicine with comprehensive insights into the current state and future prospects of sperm selection technologies in ART.

Relationship of environmental exposure temperature and temperature extremes on sperm DNA fragmentation index in men with different BMI values and the indirect effect of DNA fragmentation index on semen parameters

Prior studies have established a significant correlation between the DNA fragmentation index (DFI) and infertility. Additionally, certain investigations suggest that environmental exposure may serve as an etiological factor impacting semen quality. This study aimed to explore the impact of season, ambient temperature, and weather extremes on the DFI of sperm, along with other relevant parameters. Furthermore, it sought to assess how ambient temperature affects the DFI of sperm and other semen parameters in populations with varying BMI values. Additionally, the study analyzed the transient indirect effect of DFI on sperm parameters. This retrospective study analyzed semen samples from 11,877 men, selected based on female factor considerations, spanning from January 2016 to December 2021. Participants were grouped according to the season of semen collection. The results showed that samples collected in summer had a lower semen volume and sperm motility, while those collected in autumn had a lower DFI. We analyzed the exposure-response ratio between environmental exposure temperature and semen parameters using a generalized additive model. Results showed that the curve of the exposure-response relationship was U-shaped or inverted U-shaped; when the air temperature exposure was below the threshold, for each degree of temperature increase, the total sperm motility, sperm concentration, and progressive motility increased by 0.16 %, 0.29 × 10 (Levine, 1999)/ml and 0.14 %, respectively, while the DFI and inactivity rate decreased by 0.078 % and 0.15 %, respectively. When the air temperature exposure exceeded the threshold, for each degree of temperature increase, the sperm concentration, total sperm motility, semen volume and progressive motility decreased by 0.42 × 10 (Levine, 1999)/ml, 0.11 %, 0.0078 ml and 0.15 %, respectively, while the DFI and inactivity rate increased by 0.13 % and 0.12 %, respectively. Extremely cold weather during spermatogenesis was positively correlated with DFI, and extremely hot weather was negatively correlated with sperm motility. Subgroup analysis revealed that individuals classified as overweight / obese exhibited more pronounced changes in sperm parameters and the DFI in response to variations in environmental exposure temperature compared to those with a normal BMI. In the analysis of the relationship between DFI and sperm parameters, the results showed an inverted U-shape relationship between DFI and semen volume, and a negative correlation between DFI and sperm concentration and sperm motility. And we found that ambient temperature affects sperm parameters through DFI at low as well as average temperatures, whereas at high temperatures this indirect effect is no longer present.

Improving human sperm motility via red and near-infrared laser irradiation: in-vitro study

Improved sperm motility is necessary for successful sperm passage through the female genital system, efficacious fertilization, and a greater probability of pregnancy. By stimulating the mitochondrial respiratory chain, low-level laser photobiomodulation has been shown to increase sperm motility and velocity. The respiratory chain in mitochondria is the primary site of action for cytochrome c oxidase because it can absorb light in the visible and infrared ranges. The present study aimed to investigate the effects of red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both on human spermatozoa motility and DNA integrity at different doses. An in-vitro controlled trial was performed in Al Zahraa university hospital laboratory using thirty fresh human semen specimens. Samples were exposed to red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both for various irradiation times. Sperm motility for the test and control aliquots was assessed as recommended in the manual of WHO-2021. Sperm chromatin integrity was evaluated using the Sperm Chromatin Structure Assay. Results revealed almost 70%, 80% and 100% increase in the total motility after 3 min of the 650-nm, 980-nm and the combined laser irradiation, respectively. Additionally, the Sperm Chromatin Dispersion assay was carried out on sperm heads utilizing human sperm DNA fragmentation, demonstrating that none of the three laser types had any discernible effects.

Outcomes comparison of testicular versus ejaculated sperm for intracytoplasmic sperm injection in infertile men with high DNA fragmentation: updated systematic review and meta-analysis

Background

The testicular sperm instead of ejaculated sperm for intracytoplasmic sperm injection (ICSI) in infertile men with high sperm DNA fragmentation (SDF) is a controversial topic. This updated systematic review and meta-analysis aims to evaluate whether couples with high level of SDF will benefit more from intracytoplasmic sperm injection with testicular sperm (Testi-ICSI) as compared to intracytoplasmic sperm injection with ejaculated sperm (Ejac-ICSI).

Methods

A systematic search was conducted according to PRISMA guidelines, using PubMed, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL), encompassing studies from the earliest record until May 2022. We included studies analyzing comparative pregnancy outcomes of testicular versus ejaculated sperm for ICSI in infertile men with high DNA fragmentation. The risks of bias and certainty of evidence were assessed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework, respectively.

Results

Eleven studies were included. Meta-analysis showed that SDF levels revealed a significant difference association [odds ratio (OR) =-25.81; 95% confidence interval (CI): -34.82, -16.81; I2=94%; P<0.00001] between testicular and ejaculated sperm. Compared with Ejac-ICSI, a non-significant tendency was observed for fertilization rates (FRs) in the Testi-ICSI group (OR =0.87; 95% CI: 0.67, 1.12; I2=81%; P=0.28). However, there was significant difference pointing to better outcomes for Testi-ICSI in clinical pregnancy rates (CPRs) (OR =2.36; 95% CI: 1.71, 3.24; I2=0%; P<0.00001), live birth rates (LBRs) (OR =3.10; 95% CI: 2.13, 4.51; I2=4%; P<0.00001) and miscarriage rates (MRs) (OR =0.28; 95% CI: 0.13, 0.60; I2=0%; P=0.001).

Conclusions

Results of this updated meta-analysis reveal that SDF rates are lower in testicular sperm than in ejaculated sperm and that Testi-ICSI is correlated with better clinical outcomes, including higher CPRs, higher LBRs, and lower MRs in infertile males with high SDF levels. Nevertheless, with the overall low to moderate quality of the studies, further well-designed controlled studies are required.