Sperm deoxyribonucleic acid fragmentation as a prognostic indicator of assisted reproductive technology outcome

ICSI using testicular spermatozoa after failure of ICSI with ejaculated spermatozoa could be a good choice: A propensity score-matched cohort study

BACKGROUND

Ejaculated spermatozoa are considered to possess a higher fertilisation potential than testicular spermatozoa. In selected cases, the use of testicular spermatozoa from non-azoospermic infertile men resulted in a higher implantation and pregnancy rate than the use of ejaculated spermatozoa.

OBJECTIVE

The primary objective was to compare the live birth rate and cumulative live birth rate between couples with failed intracytoplasmic sperm injection procedure using ejaculated spermatozoa who subsequently had an intracytoplasmic sperm injection cycle with testicular spermatozoa and those who subsequently had an intracytoplasmic sperm injection cycle with ejaculated spermatozoa. The secondary objective was to determine the indications for the use of testicular spermatozoa after intracytoplasmic sperm injection failure with ejaculated spermatozoa.

MATERIALS AND METHODS

A retrospective study of matched couples using propensity score matching analysis was performed. After an intracytoplasmic sperm injection failure (cycle_1), intracytoplasmic sperm injection with either ejaculated spermatozoa (ejaculated sperm group), or testicular spermatozoa (testicular sperm group), was performed (cycle_2). The matching was on intracytoplasmic sperm injection performed in cycle_1 according to spermatozoa used (testicular or ejaculated) in cycle_2. Logistic regression was used to evaluate the influence of sperm origin on cumulative live birth rate. Univariate analysis on parameters of cycle_1 was used to identify the prognostic factors to propose an intracytoplasmic sperm injection with testicular spermatozoa in case of cycle_1 failure. The study outcomes were live birth rate and cumulative live birth rate.

RESULTS

Among the 6034 couples available, 63 were selected to constitute the testicular sperm group and 63 were selected by propensity score matching to constitute the ejaculated sperm group. After matching, the DNA fragmentation index was higher in the testicular sperm group (13.43% ± 9.65% vs. 8.93% ± 4.47%, p = 0.013); no significant difference was observed for the fertilisation rate, the number of obtained embryos, blastulation rate and frozen embryo rate. In cycle_2, the live birth rate was higher in the testicular group (22.2% vs. 0.0%, p < 0.001), as was the cumulative live birth rate (25.4% vs. 6.3%, p = 0.065). The prognostic factors identified for the proposal of intracytoplasmic sperm injection procedure with testicular spermatozoa after intracytoplasmic sperm injection failure with ejaculated spermatozoa were: teratozoospermia, cryptozoospermia and high DNA fragmentation index.

DISCUSSION

According to the present study and current knowledge, the use of testicular spermatozoa after failed intracytoplasmic sperm injection procedure in non-azoospermic men could be proposed instead of sperm donation in case of high sperm DNA fragmentation index, cryptozoospermia and teratozoospermia. A good oocyte response to ovarian stimulation during the previous assisted reproductive technology attempt will increase the chance of success. Although the main limitation of the current study is its retrospective nature, the use of the propensity score matching to perform causal inference study increases its reliability.

CONCLUSION

The present study supports that the use of testicular spermatozoa outside the classical indication of azoospermia is a good option when the indication is well established. However, before proposing a testicular biopsy, an improvement in sperm characteristics should be considered by treating the causes of sperm alteration.

Genome and Epigenome Disorders and Male Infertility: Feedback from 15 Years of Clinical and Research Experience

Infertility affects around 20% of couples of reproductive age; however, in some societies, as many as one-third of couples are unable to conceive. Different factors contribute to the decline of male fertility, such us environmental and professional exposure to endocrine disruptors, oxidative stress, and life habits with the risk of de novo epigenetics dysregulation. Since the fantastic development of new "omes and omics" technologies, the contribution of inherited or de novo genomes and epigenome disorders to male infertility have been further elucidated. Many other techniques have become available to andrology laboratories for the investigation of genome and epigenome integrity and the maturation and the competency of spermatozoa. All these new methods of assessment are highlighting the importance of genetics and epigenetics investigation for assisted reproduction pathology and for supporting professionals in counselling patients and proposing different management strategies for male infertility. This aims to improve clinical outcomes while minimizing the risk of genetics or health problems at birth.

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.

Next-Generation Sequencing to Elucidate the Semen Microbiome in Male Reproductive Disorders

Mean sperm counts are declining at an accelerated rate and infertility is increasingly becoming a public health concern. It is now understood that human semen, previously considered to be sterile, harbours its own specific microbiome. Via activated leucocytes and the generation of reactive oxygen species, bacteria have the capability of evoking an immune response which may lead to sperm damage. Men with infertility have higher rates of both reactive oxygen species and sperm DNA damage. Due to the lack of sensitivity of routine culture and PCR-based methods, next-generation sequencing technology is being employed to characterise the seminal microbiome. There is a mounting body of studies that share a number of similarities but also a great range of conflicting findings. A lack of stringent decontamination procedures, small sample sizes and heterogeneity in other aspects of methodology makes it difficult to draw firm conclusions from these studies. However, various themes have emerged and evidence of highly conserved clusters of common bacteria can be seen. Depletion or over-representation of specific bacteria may be associated with aberrations in traditional and functional seminal parameters. Currently, the evidence is too limited to inform clinical practice and larger studies are needed.

Human Papillomavirus and Male Infertility: What Do We Know?

In recent years, increasing attention has been paid to understanding the causes of infertility, which is being recognized as a growing health problem affecting large numbers of couples worldwide. Male infertility is a contributing factor in approximately 30-40% of cases, and one of its etiological causes is sexually transmitted infections (STIs). Among sexually transmitted pathogens, human papillomavirus (HPV) can contribute in various ways to the failure of spontaneous and assisted reproduction, acting in the different phases of conception, especially in the early ones. In particular, HPV infection can affect sperm DNA integrity, sperm motility, count, viability, and morphology and can induce the production of anti-sperm antibodies (ASAs). In this narrative review, we aimed to provide an overview of existing research on the potential adverse effects of HPV infection on male reproductive health. Furthermore, we analyzed how limiting the spread of the infection, particularly with gender-neutral vaccination, could be a possible therapeutic tool to counteract male and female fertility problems.

[Assessment of the man in the infertile couple]

BACKGROUND

Among couples consulting for infertility, there is a male component, either alone or associated with a female aetiology in around one in 2 cases.

MATERIAL AND METHODS

Bibliographic search in PubMed using the keywords "male infertility", "diagnosis", "management" and "evaluation" limited to clinical articles in English and French prior to 1/01/2023.

RESULTS

The AFU recommends: (1) a complete medical history including: family history, patient history affecting fertility, lifestyle habits (toxicity), treatments, symptoms, sexual dysfunctions; (2) a physical examination including: BMI, signs of hypogonadism, secondary sexual characteristics, scrotal examination (volume and consistency of testes, vas deferens, epididymal or testicular nodules, presence of varicocele); (3) two spermograms, if abnormal on the first; (4) a systematic scrotal ultrasound,± an endorectal ultrasound depending on the clinic; (5) a hormonal work-up (testosterone, FSH; if testosterone is low: LH assay to differentiate between central or peripheral hypogonadism); (6) karyotype if sperm concentration≤10 million/mL; (7) evaluation of Y chromosome microdeletions if concentration≤1 million/mL; (8) evaluation of the CFTR gene in cases of suspected bilateral or unilateral agenesis of the vas deferens and seminal vesicles. The role and usefulness of direct and indirect tests to assess the effects of oxidative stress on sperm DNA will also be explained.

CONCLUSION

This review complements and updates the AFU/SALF 2021 recommendations.

Effects of preconception exposure to phthalates on mouse sperm capacitation parameters

BACKGROUND

Phthalates have been linked to adverse male reproductive health, including poor sperm quality and embryo quality as well as a longer time to pregnancy (months of unprotected intercourse before conception occurs). The present study aimed to evaluate the effect of preconception exposure to two ubiquitous phthalate chemicals, di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and their mixture on sperm function, fertilization, and embryo development in mice.

MATERIALS AND METHODS

Adult male C57BL/6J mice aged 8-9 weeks were exposed to di(2-ethylhexyl) phthalate, di-n-butyl phthalate, or their mixture (di-n-butyl phthalate + di(2-ethylhexyl) phthalate) at 2.5 mg/kg/day or vehicle for 40 days (equivalent to one spermatogenic cycle) via surgically implanted osmotic pumps. Caudal epididymal spermatozoa were extracted and analyzed for motility using computer-assisted sperm analyses. Sperm phosphorylation of protein kinase A substrates and tyrosine phosphorylation, markers of early and late capacitation events, respectively, were analyzed by Western blots. In vitro fertilization was used to evaluate the sperm fertilizing capacity.

RESULTS

While the study did not reveal any significant differences in sperm motility and fertilization potential, abnormal sperm morphology was observed in all phthalate exposures, particularly in the phthalate mixture group. In addition, the study revealed significant differences in sperm concentration between control and exposed groups. Moreover, protein phosphorylation of protein kinase A substrates was decreased in the di(2-ethylhexyl) phthalate and mixture exposure groups, while no significant changes in protein tyrosine phosphorylation were observed in any of the groups. Assessment of the reproductive functionality did not reveal significant effects on in vitro fertilization and early embryo development rates but showed wide variability in the phthalate mixture group.

CONCLUSION

Our findings suggest that preconception phthalate exposure affects sperm numbers and phosphorylation of protein kinase A substrates involved in capacitation. Future research is warranted to examine the associations between phthalate exposure and capacitation in human spermatozoa.

Cryopreservation of Human Spermatozoa: Functional, Molecular and Clinical Aspects

Cryopreservation is an expanding strategy to allow not only fertility preservation for individuals who need such procedures because of gonadotoxic treatments, active duty in dangerous occupations or social reasons and gamete donation for couples where conception is denied, but also for animal breeding and preservation of endangered animal species. Despite the improvement in semen cryopreservation techniques and the worldwide expansion of semen banks, damage to spermatozoa and the consequent impairment of its functions still remain unsolved problems, conditioning the choice of the technique in assisted reproduction procedures. Although many studies have attempted to find solutions to limit sperm damage following cryopreservation and identify possible markers of damage susceptibility, active research in this field is still required in order to optimize the process. Here, we review the available evidence regarding structural, molecular and functional damage occurring in cryopreserved human spermatozoa and the possible strategies to prevent it and optimize the procedures. Finally, we review the results on assisted reproduction technique (ARTs) outcomes following the use of cryopreserved spermatozoa.

The efficacy of novel centrifugation-free sperm selection (Io-Lix) on sperm parameters and ICSI reproductive outcomes

RESEARCH QUESTION

What is the effect of a novel non-centrifugation method (Io-Lix) of sperm selection on sperm parameters and intracytoplasmic sperm injection (ICSI) reproductive outcomes?

DESIGN

This pilot study elevated the capacity of the Io-Lix sperm selection protocol to improve sperm parameters (concentration, motility and sperm DNA fragmentation) of the neat ejaculate. Once established, the reproductive outcomes of Io-Lix selected spermatozoa were used for autologous and donor oocyte ICSI programmes and their efficacy compared with those using conventional swim-up.

RESULTS

Io-Lix sperm selection resulted in lower sperm concentration yield (P < 0.001) and sperm DNA fragmentation (P < 0.001) but higher sperm motility (P < 0.001) when compared with spermatozoa in the neat ejaculate. When compared with swim-up sperm selection the Io-Lix protocol resulted in a 14.7% (P = 0.028) increase in pregnancy rate and 16.3% (P = 0.047) reduction in miscarriages in the autologous ICSI programme. A similar comparison of sperm selection procedures employed for a donor oocyte ICSI programme showed no difference in terms of their respective reproductive outcomes.

CONCLUSIONS

The Io-Lix sperm selection protocol resulted in improved pregnancy rate and reduction in miscarriage when applied to autologous ICSI, which was attributed to a reduction in the proportion of spermatozoa with DNA damage post-selection. A similar finding was not apparent in the donor oocyte programme, which may be associated with the capacity of the donor oocyte to repair sperm DNA post-syngamy.

Cryopreservation of Yak Semen: A Comprehensive Review

An urgent need to boost the sustainability and efficiency of animal production exists, owing to the growing global population. Enhancing the global fertility of animals, especially cattle, is essential to ameliorate this issue. Artificial insemination and sperm cryopreservation have a considerable and favorable influence on the quantity and quality of the cattle produced. Sperm cryopreservation is crucial for livestock production because it promotes and accelerates genetic diversity and the worldwide dispersion of animals with enhanced genetics. Owing to the importance of cryobiology in reproductive technologies, researchers are developing new approaches, and they are testing cryoprotectant drugs to enhance sperm cryosurvival. However, the viability of sperm after freezing is low and widely varies across breeding yaks. These faults are crucial because they impede advances in reproductive biotechnology and the study of mammalian gametes at a fundamental level. Using chemicals, researchers have developed and enhanced various extenders with varying degrees of efficiency to reduce cryodamage and oxidative stress. In this article, we review the cryopreservation of yak semen, the development of extenders, the difficulties faced during cryopreservation, and the evaluation of semen quality using various methodologies. This review might be helpful for researchers exploring semen cryopreservation in the future, as demand for enhanced cryopreservation exists to boost the post-thaw viability and fertility of sperm.

Nuclear DNA Fragmentation in Boar Spermatozoa: Measurement Methods and Reproductive Performance Implications

The aim of this research was to compare the different techniques to measure sperm nuclear DNA fragmentation (sDF) and to check its relations to boar reproductive value, classical spermiogram parameters, and reproductive results of the doses in sows. Sperm chromatin stability assay (SCSA), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and sperm chromatin dispersion test (SCD, Halomax^®) results were compared, finding a statistically significant correlation only between SCSA and TUNEL results. The fertility direct boar effect (DBE) index, calculated from the whole productive life of the boar, was not correlated (p > 0.05) with sDF (measured by any technique). Total or progressive sperm motility was not correlated with sDF, while it found a positive correlation between TUNEL measure and abnormal acrosomes (%) and between SCD measure and total sperm morphological abnormalities (%). No significant correlations were obtained between fertility or prolificacy results and sDF results with the different techniques. However, in the case of total born and SCSA measure, the correlation was close to significance (r partial = −0.095; p = 0.066), appointing to a tendency; as SCSA increases, the number of total piglets born decreases. In conclusion, although the different techniques for the sDF seem not to target exactly the same DNA events and the relationship between their values and the reproductive results and the classical spermiogram results is still to be elucidated, the studied sDF techniques may offer extra information that could be useful for the management of AI studs.

Can sperm quality influence embryo development and its ploidy? Analysis of 811 blastocysts obtained from different sperm sources

The aim of our study was to evaluate the correlation between sperm quality and ploidy status of the derived blastocysts. We performed a retrospective analysis on a restricted pool of patients enrolling only those who had no female factors. Male patients with genetic factors affecting spermatogenesis were also excluded. We chose a maternal age ≤38 years to decrease the female factor, therefore the male factor was the main component of sterility. We divided the patients in four groups based on semen quality and comparing fertilization, pregnancy and euploidy rates above all. In total, 201 intracytoplasmic sperm injection (ICSI) cycles were enrolled in the study. Cycles were divided into four groups, according to semen source: normal semen, oligoasthenoteratozoospermia (OAT), cryptospermia or non-obstructive azoospermia (NOA). An extremely statistically lower fertilization rate was found in NOA patients. Unexpectedly, no differences were detected in blastocyst formation, euploidy, aneuploidy and mosaicism rates among the four groups. Interestingly, we also found a higher abortion rate comparing NOA to normal semen with an odds ratio of 4.67. In our study no statistically significant differences among the analyzed groups were found, showing little or no effect at all using spermatozoa from different semen sources or quality. This may be linked to the oocyte competence of fixing sperm DNA damage and it could be hypothesized that only sperm with a good rate of DNA integrity are able to fertilize the oocyte, explaining why poor quality semen is reflected in a low fertilization rate without effect on ploidy.

Obesity and male infertility: multifaceted reproductive disruption

Background

The global prevalence of obesity has soared to a concerning height in the past few decades. Interestingly, the global decline in semen quality is a parallel occurrence that urges researchers to evaluate if obesity is among the most essential causatives of male infertility or subfertility.

Main body

Obesity may alter the synchronized working of the reproductive-endocrine milieu, mainly the hypothalamic-pituitary-gonadal (HPG) axis along with its crosstalks with other reproductive hormones. Obesity-mediated impairment in semen parameters may include several intermediate factors, which include physical factors, essentially increased scrotal temperature due to heavy adipose tissue deposits, and systemic inflammation and oxidative stress (OS) initiated by various adipose tissue-derived pro-inflammatory mediators. Obesity, via its multifaceted mechanisms, may modulate sperm genetic and epigenetic conformation, which severely disrupt sperm functions. Paternal obesity reportedly has significant adverse effects upon the outcome of assisted reproductive techniques (ARTs) and the overall health of offspring. Given the complexity of the underlying mechanisms and rapid emergence of new evidence-based hypotheses, the concept of obesity-mediated male infertility needs timely updates and pristine understanding.

Conclusions

The present review comprehensively explains the possible obesity-mediated mechanisms, especially via physical factors, OS induction, endocrine modulation, immune alterations, and genetic and epigenetic changes, which may culminate in perturbed spermatogenesis, disrupted sperm DNA integrity, compromised sperm functions, and diminished semen quality, leading to impaired male reproductive functions.

Comparative Effect of Photobiomodulation on Human Semen Samples Pre- and Post-Cryopreservation

The primary objective of this study is to evaluate and to compare the effects of photobiomodulation (PBM) on sperm parameters both before and after cryopreservation. In this regard, 24 freshly ejaculated semen samples from normozoospermic men were included in this study. Each semen sample was randomly divided into three groups (1 ml aliquot for each group): the control group (group one) underwent conventional sperm cryopreservation (n = 24), group two underwent pre-freezing PBM exposure (810 nm, diode laser, and 0.6 J/cm²) (n = 24), and group three underwent post freezing and thawing PBM exposure (n = 24). Indicators of sperm quality, including total sperm motility (TSM), progressive sperm motility (PSM), DNA fragmentation, lipid peroxidation levels, apoptosis-like changes, and gene expression levels of protamine (PRM) 1, PRM2, and adducin 1 alpha (ADD1), were investigated in a blinded style. Due to the beneficial effect of pre-freezing PBM therapy, group 2 exhibited the highest TSM and PSM levels compared to groups 1 and 3. At the same time, DNA fragmentation and lipid peroxidation were significantly reduced in the group 2 compared to the group 1 (p = 0.024 p = 0.016, respectively). Evaluation of apoptotic/necrotic changes revealed that parameters including early apoptosis, dead, and necrotic cells decreased in the group 2 compared to the either groups 1 (p = 0. 008, p = 0. 032, p = 0. 02, respectively) or group 3 (p = 0.037, p = 0.108, p = 0.083). There were no significant differences in the expression levels of PRM1, PRM2, and ADD1 among the study groups. Based on our results, PBM therapy prior to cryopreservation, even in the normal semen samples, plays a significant protective role against cryo-damage by preserving the functional parameters of spermatozoa.

Cryoprotectant With A Mitochondrial Derived Peptide, Humanin, Improves Post-Thaw Quality Of Buffalo Spermatozoa

BACKGROUND: Semen cryopreservation results in deleterious effects on spermatozoa, including lipid peroxidation and a reduction in the total antioxidant components of seminal plasma. The ultimate outcome of these changes is a reduction in post-thaw semen quality. A mitochondrial derived peptide, humanin, a potent cytoprotective and antioxidant agent was used in the present study. OBJECTIVE: To evaluate the efficacy of a mitochondrial-derived peptide, humanin to improve the post-thaw quality of buffalo spermatozoa. MATERIALS AND METHODS: A total of 18 ejaculates from three Murrah buffalo bulls (n=6 each) were collected. Each ejaculate was divided into four aliquots. The first aliquot was diluted with standard EYTG dilutor (Group I, control), whereas the other three aliquots were diluted with EYTG supplemented with 2 μM (Group II), 5 μM (Group III) and 10 μM humanin (Group IV), respectively. Semen was evaluated for physico-morphological and functional attributes such as progressive motility, viability, abnormality, acrosome integrity, plasmamembrane integrity of fresh samples, pre-freeze and post-thaw stages. Oxidative stress parameters [lipid peroxidation (LPO) and total antioxidant capacity (TAC)] were also measured at the pre-freeze and post-thaw stages. RESULTS: Humanin s upplementation resulted in significantly higher (p≤0.05) post- thaw motility in all treatment groups and, higher (p≤0.05) viability in Groups III and IV in comparison to the control at the post-thaw stage. Spermatozoa with intact acrosome and plasma membran e were higher (p≤0.05) in Groups III and IV as compared to Group s I and II. The LPO levels at the post- thaw stage were found to be lower (p≤0.05) in all treatment groups versus the control group, whereas, higher (p≤0.05) TAC value s were recorded in Groups III and IV in comparison to the control and Group II. CONCLUSION: Humanin supplementation in the extender improved the freezabilty of buffalo spermatozoa.

The relationship between genitourinary microorganisms and oxidative stress, sperm DNA fragmentation and semen parameters in infertile men

An imbalance in the genitourinary microbiome is emerging as a contributing factor to male infertility. The purpose of this study was to determine whether there is an association between genitourinary microorganisms and seminal oxidative stress, sperm DNA fragmentation and semen parameters. It included 770 men attending for diagnostic testing for subfertility. Genitourinary microorganisms were identified in 43.0% men; 20.1% had microorganisms in semen; 18.7% in urine; and 5.8% had microorganisms in urine and semen. Enterococcus faecalis was the most prevalent organism in semen (22.0% samples; 61.5% organisms) with Ureaplasma spp. (16.9% samples; 53.3% organisms) and Gardnerella vaginalis (11.4% samples; 37.4% organisms) most prevalent in urine. Semen parameters were unaffected by microorganisms (p > 0.05). Seminal ROS were significantly higher in men with microorganisms compared to those without (p < 0.001), particularly when present in both urine and semen (p < 0.01). Microorganisms were associated with significantly higher DNA fragmentation, irrespective of whether they were in semen or urine (p < 0.001). An imbalance in the genitourinary microbiome is associated with DNA damage and oxidative stress which may have considerable consequences for achieving an ongoing pregnancy. This highlights the need for incorporating genitourinary microorganism screening for all men as part of diagnostic evaluation prior to undergoing treatment for infertility.

Outcomes of Frozen Oocyte Donor In Vitro Fertilization (IVF) Cycles Using Fresh Versus Frozen Sperm

The ability to use frozen sperm for insemination during in vitro fertilization (IVF) is crucial for patients and for reproductive endocrinologists. However, concerns exist regarding the effects of cryopreservation on sperm quality and IVF outcomes. This study compares outcomes of frozen donor oocyte IVF cycles with intracytoplasmic sperm injection (ICSI) of good quality fresh versus frozen ejaculated sperm. Patients who underwent their first frozen donor oocyte IVF cycle between 2013 and 2019 at Mayo Clinic were identified. The primary outcome was live birth rate (LBR). Secondary outcomes included fertilization rate (FR), blastocyst development rate (BR), and clinical pregnancy rate (CPR). Twenty-six patients used fresh sperm and 19 patients utilized frozen sperm; there were no significant demographic differences between the groups. There were no significant differences noted in CPR, FR, and BR. Although the LBR was not statistically different when frozen versus fresh sperm was utilized (52.6% vs. 61.5%, p = 0.55), there was a distinct trend towards improved outcomes with fresh sperm that may be clinically significant. This data suggests that frozen sperm may be an alternative to a fresh sample, however fresh sperm may ultimately be a better option. This finding should be further explored with studies utilizing a larger sample size.

Does Microfluidic Sperm Sorting Affect Embryo Euploidy Rates in Couples with High Sperm DNA Fragmentation?

Male infertility contributes as the main factor in 30-50% of infertility cases. Conventional methods for sperm preparation have induced questioning of sperm recovery rates. The microfluidic sperm sorting (MSS) technique selects highly motile sperm with lower levels of SDF (sperm DNA fragmentation) compared to conventional sperm sorting techniques. This study aimed to determine whether utilizing this technique will reveal better embryo quality and euploidy rates in couples with repeated implantation failure (RIF) and high SDF in a new PGT-A (preimplantation genetic testing for aneuploidies) cycle. This retrospective study included couples referred to PGT-A for previous repeated ART (assisted reproductive techniques) cycle failures and with high SDF. In their new cycles, couples who accepted the technique were assigned to the MSS group, and the rest were managed with DGC (density-gradient centrifugation). Two groups were compared in terms of fertilization and euploidy rates, clinical miscarriage and live birth rates, the total number of blastocysts, and top quality blastocysts. There was no difference between the groups regarding fertilization rates, euploidy rates, clinical miscarriage, and live birth rates. The total number of blastocysts and top quality blastocysts were significantly higher in the MSS group. The MSS technique provides a higher number of top-quality blastocysts than DGC; however, neither euploidy nor live birth rates improved. Studies focusing on confounding factors to embryonic genomic status in the presence of high SDF are needed.

Correlation of sperm DNA damage with blastocyst formation: systematic review and meta-analysis

Background

The routine semen analysis fails to detect sperm DNA damage which contributes to the majority of male factor infertility. Sperm DNA fragmentation test (DFI) measures the sperm DNA damage. Blastocyst formation is an important step in IVF ± ICSI. At present, the literature lacks any data that correlates DFI and blastocyst formation.

Main body of the abstract

We searched MEDLINE and other databases till 2020 for the studies that reported on sperm DNA damage and blastocyst formation in assisted reproductive technology (ART). The outcomes analyzed were (1) a comparison of blastulation rates in high DFI and low DFI groups. (2) Comparison of blastulation rates in high DFI and low DFI groups based on (a) different sperm DNA fragmentation assays (COMET, SCD, SCSA, TUNEL), (b) different types of ART (IVF/IVF + ICSI/ICSI). 10 studies were included in this review. A non-significant increase in the blastocyst formation was observed in high DFI group (OR = 0.70; 95% CI = 0.4 to 1.21; P = 0.20) and with SCD and TUNEL assays.

Short conclusion

Our study emphasizes on sperm DNA fragmentation (sperm DNA damage) as an important marker of blastocyst formation. The results of this meta-analysis suggest that the high sperm DNA fragmentation may not adversely affect the blastocyst formation.

Predictive Significance of Sperm DNA Fragmentation Testing in Early Pregnancy Loss in Infertile Couples Undergoing Intracytoplasmic Sperm Injection

Objective

This study aimed to determine the role of sperm DNA fragmentation as a marker that could predict early pregnancy loss (EPL), either independently or in combination with another marker or markers, after intracytoplasmic sperm injection (ICSI) cycles.

Methods

This prospective descriptive cohort study retrieved data from 162 couples who underwent their first ICSI cycles at the Center for Reproductive Endocrinology and Infertility of Hue University Hospital in Vietnam from May 2018 to December 2019. General characteristics, semen parameters, sperm DNA fragmentation index (DFI), fertilization, embryo development, pregnancy rates, and EPL were assessed. The receiver-operating characteristic (ROC) method was performed to identify the threshold of DFI in EPL. Multivariate analysis was used to demonstrate the relationship between the sperm DNA fragmentation level and EPL.

Results

Of 162 ICSI cycles, 23 (14.2%) involved EPL. There was no significant difference between the sperm DNA fragmentation rate and the overall rate of pregnancy loss, although the negative pregnancy outcome group had a median DFI that was higher than that of the positive pregnancy outcome group (20% vs 17.8%). The ROC analysis indicated that a sperm DNA fragmentation rate of 16.6% was the priority cut-off that could be used to distinguish EPL with a sensitivity of 73.9% (95% confidence interval [CI], 67.15-80.67) and specificity of 47.48% (95% CI, 39.79-55.17). The multivariate analysis confirmed that in female factors such as age, body mass index (BMI), and sperm DNA fragmentation level affected the EPL rate. However, a combination of the sperm DNA fragmentation level and female age or female BMI could not sufficiently predict EPL.

Conclusion

EPL can be affected by multiple factors including sperm DNA fragmentation; however, there is no sufficient evidence indicating that sperm DNA fragmentation, both as a single marker and combined with other markers, is a good predictor of EPL.

Sperm DNA fragmentation measured by sperm chromatin dispersion impacts morphokinetic parameters, fertilization rate and blastocyst quality in ICSI treatments

To determine the effects of sperm DNA fragmentation (SDF) on embryo morphokinetic parameters, cleavage patterns and embryo quality, this retrospective study analyzed 151 intracytoplasmic sperm injection (ICSI) cycles (1152 embryos collected) between November 2016 and June 2019. SDF was assessed using sperm chromatin dispersion. The cycles were divided into two groups based on the SDF rate: SDF < 15% (n = 114) and SDF ≥ 15% (n = 37). The embryo morphokinetic parameters, cleavage patterns, and embryo quality were compared between the two groups. The morphokinetic parameters tPNf, t2, t3, t4, t5, t6, and t8 were achieved significantly earlier in the SDF < 15% group compared with in the SDF ≥ 15% group. The fertilization and 2PN rates seemed to be significantly higher in the SDF < 15% group compared with in the SDF ≥ 15% group, while the abnormal cleavage rates were similar. However, a significantly higher rate of chaotic cleavage (CC) was observed in the SDF ≥ 15% group. The D3 high-quality embryo and available embryo rates were similar between the two groups. The blastocyst formation, high-quality blastocyst, and available blastocyst rates in the SDF < 15% group were significantly higher than those in the SDF ≥ 15% group. With an increase in SDF level, the chemical pregnancy, clinical pregnancy and implantation rates tended to decrease, while the miscarriage rate increased. This study demonstrated that SDF ≥ 15% reduces the fertilization rate of ICSI cycles and affects certain morphokinetic parameters. A higher SDF level can also induce a higher rate of CC, with subsequent decreases in the blastocyst formation rate and blastocyst quality.

Liquid chromatography-tandem mass spectrometry reveals an active response to DNA damage in human spermatozoa

OBJECTIVE

To investigate how endogenously elevated DNA fragmentation alters the human sperm proteome, and whether this fragmentation contributes to genomic deletions.

DESIGN

Research study.

SETTING

Commercial fertility clinic.

PATIENT(S)

Men with low (0%-4%, n = 7) or high (≥16%, n = 6) sperm DNA fragmentation, as assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling assay.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Global sperm proteome, single-nucleotide polymorphism genotyping array.

RESULT(S)

A total of 78 significantly differentially abundant proteins (30 decreased, 48 increased) were observed in control vs. high DNA damage samples. DNA damage resulted in robust proteomic responses, including markers of oxidative stress and apoptosis, DNA damage repair proteins, and transcription/translation and protein turnover machinery. Several key sperm functional proteins were significantly decreased in ejaculates with high DNA damage. We were unable to substantiate a link between increased DNA fragmentation and genomic deletions in human spermatozoa.

CONCLUSION(S)

Developing human spermatozoa initiate an active transcriptional response to endogenous DNA damage, which manifests as alterations in the sperm proteome.

Clinical implications of sperm DNA damage in IVF and ICSI: updated systematic review and meta-analysis

The clinical effect of sperm DNA damage in assisted reproduction has been a controversial topic during recent decades, leading to a variety of clinical practice recommendations. While the latest European Society of Human Reproduction and Embryology (ESHRE) position report concluded that DNA damage negatively affects assisted reproduction outcomes, the Practice Committee of the American Society for Reproductive Medicine (ASRM) does not recommend the routine testing of DNA damage for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Herein, our aim was to perform a systematic review and meta-analysis of studies investigating whether sperm DNA damage affects clinical outcomes in IVF and ICSI, in order to contribute objectively to a consistent clinical recommendation. A comprehensive systematic search was conducted according to PRISMA guidelines from the earliest available online indexing year until March 2020, using the MEDLINE-PubMed and EMBASE databases. We included studies analysing IVF and/or ICSI treatments performed in infertile couples in which sperm DNA damage was well defined and assessed. Studies also had to include information about pregnancy, implantation or live birth rates as primary outcomes. The NHLBI-NIH quality assessment tool was used to assess the quality of each study. Meta-analyses were conducted using the Mantel-Haenszel method with random-effects models to evaluate the Risk Ratio (RR) between high-DNA-damage and control groups, taking into account the 95% confidence intervals. Heterogeneity among studies was evaluated using the I² statistic. We also conducted sensitivity analyses and post-hoc subgroup analyses according to different DNA fragmentation assessment techniques. We identified 78 articles that met our inclusion and quality criteria and were included in the qualitative analysis, representing a total of 25639 IVF/ICSI cycles. Of these, 32 articles had sufficient data to be included in the meta-analysis, comprising 12380 IVF/ICSI cycles. Meta-analysis revealed that, considering IVF and ICSI results together, implantation rate (RR = 0.74; 95% CI = 0.61-0.91; I²  = 69) and pregnancy rate (RR = 0.83; 0.73-0.94; I²  = 58) are negatively influenced by sperm DNA damage, although after adjustment for publication bias the relationship for pregnancy rate was no longer significant. The results showed a non-significant but detrimental tendency (RR = 0.78; 0.58-1.06; I²  = 72) on live birth rate. Meta-analysis also showed that IVF outcomes are negatively influenced by sperm DNA damage, with a statistically significant impact on implantation (RR = 0.68; 0.52-0.89; I²  = 50) and pregnancy rates (RR = 0.72; 0.55-0.95; I²  = 72), although the latter was no longer significant after correction for publication bias. While it did not quite meet our threshold for significance, a negative trend was also observed for live birth rate (RR = 0.48; 0.22-1.02; I²  = 79). In the case of ICSI, non-significant trends were observed for implantation (RR = 0.79; 0.60-1.04; I²  = 72) or pregnancy rates (RR = 0.89; 0.78-1.02; I²  = 44), and live birth rate (RR = 0.92; 0.67-1.27; I²  = 70). The current review provides the largest evidence to date supporting a negative association between sperm DNA damage and conventional IVF treatments, significantly reducing implantation and pregnancy rates. The routine use of sperm DNA testing is therefore justified, since it may help improve the outcomes of IVF treatments and/or allow a given couple to be advised on the most suitable treatment. Further well-designed controlled studies on a larger number of patients are required to allow us to reach more precise conclusions, especially in the case of ICSI treatments.

Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations

We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations. Of these, 13 recommendations concern technical aspects of sperm DNA fragmentation testing, including pre-analytical information, clinical thresholds and interpretation of results. The remaining 28 recommendations relate to indications for sperm DNA fragmentation testing and clinical management. Clinical scenarios like varicocele, unexplained infertility, idiopathic infertility, recurrent pregnancy loss, intrauterine insemination, in vitro fertilisation/intracytoplasmic sperm injection, fertility counselling for men with infertility risk factors and sperm cryopreservation have been contemplated. The bulk evidence supporting the recommendations has increased in recent years, but it is still of moderate to low quality. This guideline provides clinicians with advice on best practices in sperm DNA fragmentation testing. Also, recommendations are provided on possible management strategies to overcome infertility related to sperm DNA fragmentation, based on the best available evidence. Lastly, we identified gaps in knowledge and opportunities for research and elaborated a list of recommendations to stimulate further investigation.

Peijingsu effectively improves sperm DNA integrity

Intact human sperm DNA is an essential prerequisite for successful fertilization and embryo development. Abnormal sperm DNA fragmentation is a independent factor for male infertility. The objective of this study was to investigate the effects of Peijingsu, a health product, on the DNA integrity of human sperm. Peijingsu was administered for 15 days to 22 patients who had an abnormal sperm DNA fragmentation index (DFI). The DFIs before and after treatment were compared and analyzed using paired t-test. DFIs decreased significantly (P = 0.0008) after treatment, therefore it was concluded that Peijingsu effectively improved sperm DNA integrity in infertile patients who had an abnormal sperm DFI.

Decreased DNA Repair Ability: A Mechanism for Low Early Embryonic Development Potential of Oocytes From Overweight Patients After Fertilization in IVF Cycles

BACKGROUND

Whether female BMI impacts the DNA repair ability in the oocytes after fertilization has not been investigated. The aim of this study is to assess the early embryo quality and reproductive outcomes of oocytes from overweight women when fertilized with sperm with varying degrees of DNA fragmentation.

METHODS

A total number of 1,612 patients undergoing fresh autologous in vitro fertilization (IVF) cycles was included. These patients were divided into two groups according to maternal body mass index (BMI): normal weight group (18.5-24.9 kg/m²; n=1187; 73.64%) and overweight group (≥25 kg/m²; n=425; 26.36%). Each group was then subdivided into two groups by sperm DNA fragmentation index (DFI): low fragmentation group (<20% DFI, LF) and high fragmentation group (≥20% DFI, HF). Laboratory and clinical outcomes were compared between subgroups.

RESULTS

For the normal-weight group, there was no statistical significance in embryo quality and reproductive outcomes between the LF and HF groups. But in the overweight group, significantly lower fertilization rate (LF: 64%; HF: 59%; p=0.011), blastocyst development rate (LF: 57%; HF: 44%; p=0.001), as well as high-quality blastocyst rate (LF: 32%; HF: 22%; p=0.034) were found in the HF group, despite the similar pregnancy rates (LF: 56%; HF: 60%; p=0.630).

CONCLUSIONS

Decreased DNA repair activity in oocytes may be a possible mechanism for the low early development potential of embryos from overweight patients in in vitro fertilization cycles.

Cellular and Functional Physiopathology of Bull Sperm With Altered Sperm Freezability

The objective of this study was to ascertain the cellular and functional parameters as well as ROS related changes in sperm from bulls with varied sperm freezability phenotypes. Using principal component analysis (PCA), the variables were reduced to two principal components, of which PC1 explained 48% of the variance, and PC2 explained 24% of the variance, and clustered animals into two distinct groups of good freezability (GF) and poor freezability (PF). In ROS associated pathophysiology, there were more dead superoxide anion positive (Dead SO+) sperm in GF bulls than those in PF (15.72 and 12.00%; P = 0.024), and that Dead SO+ and live hydrogen positive cells (live H₂O₂+) were positively correlated with freezability, respectively (R² = 0.55, P < 0.0130) and (r_s = 0.63, P = 0.0498). Related to sperm functional integrity, sperm from PF bulls had greater dead intact acrosome (DIAC) than those from GF bulls (26.29 and 16.10%; P = 0.028) whereas sperm from GF bulls tended to have greater live intact acrosome (LIAC) than those from PF bulls (64.47 and 50.05%; P = 0.084). Sperm with dead reacted acrosome (DRAC) in PF bulls were greater compared to those in GF (19.27 and 11.48%; P = 0.007). While DIAC (R² = 0.56, P = 0.0124) and DRAC (R² = 0.57, P < 0.0111) were negatively correlated with freezability phenotype, LIAC (R² = 0.36, P = 0.0628) was positively correlated. Protamine deficiency (PRM) was similar between sperm from GF and PF bulls (7.20 and 0.64%; P = 0.206) and (r_s = 0.70, P = 0.0251) was correlated with freezability. Sperm characteristics associated with cryotolerance are important for advancing both fundamental andrology and assisted reproductive technologies across mammals.

Investigation of molecular cryopreservation, fertility potential and microRNA-mediated apoptosis in Oligoasthenoteratozoospermia men

Investigation of the cryo-injury mechanism can provide novel insight into cryopreservation. The objective of this study is to assess the effect of cryopreservation on fertility potential, motility, oxidative stress (OS), DNA fragmentation, microRNAs (miRNAs), and apoptotic target genes in the infertile men compared to the fertile men. All 40 samples were divided into two leading groups of fresh and cryopreserved sperms. Each main group was subdivided into three groups including, Normozoospermia, and Mild, and Severe Oligoasthenoteratozoospermia (OAT). In all collected samples the following were assessed: microRNA-34c (miR-34c) and miR-184, P53 and Caspase9 using Quantitative real-time polymerase chain reaction (RT-PCR), malondialdehyde (MDA), Superoxide dismutase (SOD) using imaging multi-mode reader, and DNA fragmentation using Sperm DNA Fragmentation Assay Test (SDFA). Within the studied groups, immotile spermatozoa were increased due to cryopreservation. We observed an increasing levels of SOD, MDA, and DNA fragmentation. Also, cryopreservation was associated with decreasing the expression of P53, mir-43c, and miR-184 while capase9 was showed enhancing expression after freeze-thawing of sperm cells. During cryopreservation, sperm fertility and motility were influenced via apoptosis cascade-mediated mitochondrial dysfunctions such as caspase9. Also, we found that miR-34c, miR184, and P53 could impact fertility potential. In Addition, there was a meaningful correlations between microRNAs and motility post freeze-thawing process in Severe Oligoasthenoteratozoospermia men.

Sperm DNA Fragmentation: A New Guideline for Clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Mitigating the Effects of Oxidative Sperm DNA Damage

Sperm DNA damage is correlated with reduced embryo development and increased miscarriage risk, reducing successful conception. Given its links with oxidative stress, antioxidants have been investigated as a potential treatment, yet results are conflicting. Importantly, individual antioxidants are not identical in composition, and some compounds may be more effective than others. We investigated the use of the polyphenol-rich, high-antioxidant-capacity fruit acai as a treatment for elevated sperm DNA fragmentation (>16%), measured by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Following ≥ 74 days of treatment, we observed a significant decrease in sperm DNA fragmentation (-17.0% ± 2.5%) to 11.9 ± 1.7% (0-37%), with a 68.6% success rate (defined as post-treatment TUNEL < 16%). Post-treatment decreases in DNA fragmentation and success rates were not significantly impacted by low motility and/or concentration, or exceptionally high (> 25%) TUNEL. Treatment significantly reduced concentration in men with normal semen parameters, but 88% remained normal. Overall, successful treatment was not associated with age, semen parameters or TUNEL result at baseline. However, body mass index was significantly higher in nonresponders at baseline. This study provides evidence of a low-cost, effective treatment for elevated sperm DNA damage using acai.

Sperm DNA Integrity and Male Fertility in Farm Animals: A Review

The accurate prediction of male fertility is of major economic importance in the animal breeding industry. However, the results of conventional semen analysis do not always correlate with field fertility outcomes. There is evidence to indicate that mammalian fertilization and subsequent embryo development depend, in part, on the inherent integrity of the sperm DNA. Understanding the complex packaging of mammalian sperm chromatin and assessment of DNA integrity could potentially provide a benchmark in clinical infertility. In the era of assisted reproduction, especially when in-vitro fertilization or gamete intrafallopian transfer or intracytoplasmic sperm injection is used, assessment of sperm DNA integrity is important because spermatozoa are not subjected to the selection process occurring naturally in the female reproductive tract. Although sperm DNA integrity testing measures a significant biological parameter, its precise role in the infertility evaluation in farm animals remains unclear. In this review, the earlier findings on sperm DNA integrity in relation to male fertility are compiled and analyzed. Furthermore, the causes and consequences of sperm DNA damage are described, together with a review of advances in methods for detection of sperm DNA damage, and the prognostic value of sperm DNA quality on male fertility.

Diagnostic value of advanced semen analysis in evaluation of male infertility

Conventional semen analysis is the standard of care to initially evaluate the fertility status of a male patient. However, it has some limitations and among these are failure to correctly identify the aetiology underlying fertility problems, intra- and inter-observer variability and incomplete information about sperm function. Considering these drawbacks, advanced semen tests have been developed to assess male infertility, including sperm function tests, oxidative stress (OS) and sperm DNA fragmentation (SDF) tests. This review illustrates the commonly utilised sperm function techniques, along with the assays used to assess SDF and OS and their diagnostic value.

Obesity and male infertility: Mechanisms and management

Obesity is considered a global health problem affecting more than a third of the population. Complications of obesity include cardiovascular diseases, type 2 diabetes mellitus, malignancy (including prostatic cancer), neurodegeneration and accelerated ageing. In males, these further include erectile dysfunction, poor semen quality and subclinical prostatitis. Although poorly understood, important mediators of obesity that may influence the male reproductive system include hyperinsulinemia, hyperleptinemia, chronic inflammation and oxidative stress. Obesity is known to disrupt male fertility and the reproduction potential, particularly through alteration in the hypothalamic-pituitary-gonadal axis, disruption of testicular steroidogenesis and metabolic dysregulation, including insulin, cytokines and adipokines. Importantly, obesity and its underlying mediators result in a negative impact on semen parameters, including sperm concentration, motility, viability and normal morphology. Moreover, obesity inhibits chromatin condensation, DNA fragmentation, increases apoptosis and epigenetic changes that can be transferred to the offspring. This review discusses the impact of obesity on the male reproductive system and fertility, including associated mechanisms. Furthermore, weight management strategies, lifestyle changes, prescription medication, and complementary and alternative medicine in the management of obesity-induced subfertility is discussed.

The effects of Pb on sperm parameters and sperm DNA fragmentation of men investigated for infertility

Background Lead (Pb) is one of the metals most prevalent in the environment and is known to cause infertility and deoxyribonucleic acid (DNA) fragmentation. This study aimed to determine the association between seminal plasma Pb and sperm DNA fragmentation in men investigated for infertility. Methods Male partners (n = 300) of couples investigated for infertility were recruited after informed consent was obtained. Sperm parameters were assessed according to the World Health Organization (WHO) guidelines. Seminal plasma Pb was estimated by atomic absorption spectrophotometry after digestion with nitric acid. Results In Pb-positive and -negative groups the sperm parameters and sperm DNA fragmentation were compared using independent sample t-test and the Mann-Whitney U-test, respectively. The mean [standard deviation (SD)] age and duration of infertility were 34.8 (5.34) years and 45.7 (35.09) months, respectively, and the mean Pb concentration was 15.7 μg/dL. In Pb positives compared to Pb negatives the means (SD) of sperm count, progressive motility viability and normal morphology were lower (p > 0.05) but the DNA fragmentation was significantly higher 39.80% (25.08) than Pb negatives 22.65% (11.30). Seminal plasma Pb concentration and sperm DNA fragmentation had a positive correlation (r = 0.38, p = 0.03). A negative correlation was observed between sperm DNA fragmentation and sperm concentration, progressive motility, total motility and viability. When the DNA fragmentation was ≥30% sperm concentration and viability decreased (p < 0.05). Conclusions Pb in seminal plasma had a significant effect on sperm DNA fragmentation but not with other sperm parameters.

Impact of time between repeated sperm freezing cycles on sperm quality

Refreezing of sperm samples would provide the possibility of performing more cycles of fertility treatments. Although the effect of repeated cycles of freezing on sperm quality was studied, the effect of the length of the time interval between each freeze-thaw cycle has not been reported. Hence, we assessed the effect of incubation time on the sperm quality of thawed sperm after repeated freezing. One-hundred samples of potential sperm donations with normal sperm quality were evaluated. The fresh semen samples were analyzed and cryopreserved in liquid nitrogen until use. After thawing, the samples were divided randomly to two groups and reanalyzed for motility, vitality, and DNA fragmentation. They were incubated at room temperature and reanalyzed after either 90 min (group A) or 180 min (group B) of incubation, and once again after a repeated cycle of freezing and thawing. Our results showed that the sperm parameters of fresh samples of both groups were similar. After one freeze-thaw cycle, both groups still had comparable values. At the end of their respective incubation time periods, however, there was a significant difference in the mean values of the assessed parameters between the two groups (p < 0.01). An additional freeze-thaw cycle further exacerbated those differences, with group B undergoing an even more substantial decline (p < 0.001). Our data suggest that thawed human spermatozoa sustain a significant decline in sperm parameters in association with longer incubation time, which is further exacerbated by an additional freeze-thaw cycle.

Can the SCD test and terminal uridine nick-end labeling by flow cytometry technique (TUNEL/FCM) be used interchangeably to measure sperm DNA damage in routine laboratory practice?

Background

Numerous tests have been proposed to evaluate sperm DNA integrity. To assess the sperm chromatin dispersion (SCD) test in an andrology laboratory, twenty-five men attending Clermont-Ferrand (France) University Hospital’s Center for Reproductive Medicine were recruited. Sperm DNA damage was measured in the same semen samples using the SCD test and the Terminal Uridine Nick-end Labeling by flow cytometry technique (TUNEL/FCM) after density gradient centrifugation.

Results

SCD test reliability between readings, readers or slides was clearly established with very high agreement between measurements (Intraclass correlation coefficient (ICC) at 0.97, 0.95 and 0.98 respectively). Despite very good agreement between the SCD test and TUNEL/FCM (ICC at 0.94), the SCD test tended to slightly but significantly underestimate DNA damage compared with TUNEL (p = 0.0127). This systematic difference between the two techniques was − 3.39 ± 1.45% (mean ± SE).

Conclusions

Andrology laboratories using the SCD test to measure sperm DNA damage need to know that it appears to give slightly underestimated measurements compared to TUNEL/FCM. However, this systematic underestimation is very small in amplitude. Both techniques give almost perfectly congruent results. Our study underlines the importance for each laboratory to validate its method to assess sperm DNA damage before implementing it in routine andrology lab practice.

Zeta and hyaluronic acid assessments, novel sperm selection procedures, in animal model for male infertility

Considering varicocele (VCL)-induced severe, progressive DNA damage, histone-protamine anomalies and low sperm production, in the current study, the experimental VCL was induced and the efficiency of hyaluronic acid (HA)-binding method (HABM) and zeta preparation procedure (ZPP) in selection of appropriate spermatozoa was compared with those spermatozoa from intact animals. Following 2 and 4 months, the histological alterations in testicular tissue, sperm count and viability were assessed to prove the VCL condition. The spermatozoa were undergone simple wash, HABM and ZPP. The chromatin condensation, active caspase-3 expression, DNA fragmentation and apoptosis index were analysed after applying selection techniques and compared with the spermatozoa from intact and VCL-induced animals, which were undergone a simple wash. Observations showed that both HABM and ZPP effectively prepared the spermatozoa with higher chromatin condensation and lower DNA damage. Meanwhile, the ZPP exerted a more preferable effect by preparing the spermatozoa with higher chromatin condensation, and lower caspase-3 expression, and DNA disintegrity versus the HABM, especially after 4 months. In conclusion, ZPP seems to exert much more reliable efficiency in selecting appropriate spermatozoa for ICSI processes, while more studies are needed to find out which one is more useful in the clinical assisted reproductive technique (ART) process.

Characterization of DNA cleavage produced by seminal plasma using leukocytes as a cell target

Numerous studies have shown the presence of DNA lesions in human spermatozoa affecting sperm quality. However, the nature of this anomaly and its relationship with patient etiology are poorly understood since different mechanisms can be involved in the formation of these novel DNA configurations including the action of a seminal plasma nuclease activity. The objective of this study was to assess the capacity of seminal plasma for producing endogenous DNA cleavage using nuclei of peripheral blood leukocytes as external targets. For this purpose, we used seminal plasma from fertile males with normal semen parameters to produce DNA cleavage in a sample of leukocytes. Three different tests were performed to visualize DNA cleavage: (a) DNase activity detection, (b) DNA Breakage Detection-Fluorescence In Situ Hybridization (DBD-FISH), and (c) Two-dimensional comet assay (Two-tail comet assay). Our results demonstrate that: (i) the seminal plasma is able to cleave DNA compacted with histones in the leukocytes; (ii) this DNA cleavage can be associated with DNase activity and (iii) DNA damage mainly corresponds to single-strand DNA breaks. In conclusion, capacity of seminal plasma for producing DNA cleavage represents a solid contribution to expand the analysis of the standard seminal profile and could constitute a putative diagnostic tool for evaluating male infertility.Abbreviations: ALS: alkali labile sites; ART: Assisted Reproduction Technologies; DBD-FISH: DNA Breakage Detection-Fluorescence In Situ Hybridization; DNA: deoxyribonucleic acid; DSBs-DNA: double-strand DNA; FITC: Fluorescein IsoThioCyanate; GEDA: Gravity Enforced Diffusion Assays; PBS: phosphate-buffered saline; ROS: Reactive Oxigen Species; SSBs-DNA: single-strand DNA; SSC: saline-sodium citrate.

Advances in Cryopreservation of Bull Sperm

Cryopreservation of semen and artificial insemination have an important, positive impact on cattle production, and product quality. Through the use of cryopreserved semen and artificial insemination, sperm from the best breeding bulls can be used to inseminate thousands of cows around the world. Although cryopreservation of bull sperm has advanced beyond that of other species, there are still major gaps in the knowledge and technology bases. Post-thaw viability of sperm is still low and differs significantly among the breeding bulls. These weaknesses are important because they are preventing advances both in fundamental science of mammalian gametes and reproductive biotechnology. Various extenders have been developed and supplemented with chemicals to reduce cryodamage or oxidative stress with varying levels of success. More detailed insights on sperm morphology and function have been uncovered through application of advanced tools in modern molecular and cell biology. This article provides a concise review of progress in the cryopreservation of bull sperm, advances in extender development, and frontiers using diverse techniques of the study of sperm viability. This scientific resource is important in animal biotechnology because with the advances in discovery of sperm fertility markers, there is an urgent need to improve post-thaw viability and fertility of sperm through enhanced cryopreservation for precision agriculture to produce food animals to ensure food security on the global scale.

Flow cytometry in assessment of sperm integrity and functionality – a review

Spermatozoa must possess many attributes to fertilize an egg but few laboratory methods can assess all of these attributes simultaneously and objectively. Most laboratory methods used to assess the quality of semen in veterinary andrology can be inaccurate and time-consuming. Laboratory techniques which evaluate only one sperm attribute, often provide results that have a weak correlation with fertility. Therefore, semen used for artificial insemination should not be assessed based on the results of one method only but rather on the comprehensive results of several laboratory tests. Flow cytometry is a modern method of analysing diJ169fferent types of cells, including sperm cells. It is based on the scattering of light and fluorescence, the outcome of which yields results that are recorded and evaluated by computer technology which makes an objective assessment. Flow cytometry in combination with fluorescence microscopy and fluorescent probes provides a comprehensive, accurate, objective, and rapid analysis of the ejaculate. In a short time frame it allows us to test thousands of sperm for their structure and properties, even with a minimal amount of semen. This method enables the evaluation of several indicators simultaneously in a population of sperm as a whole or for each sperm individually. It informs us about the selected indicators of sperm quality in the sample by examining the membrane integrity, DNA, mitochondria, acrosome, oxidative stress, and other properties. Flow cytometry has become an important method of evaluating the functional and morphological properties of sperm and is used for research in veterinary science as well as for a routine assessment of the semen quality.

The Effect of Sperm DNA Fragmentation Index on the Outcome of Intrauterine Insemination and Intracytoplasmic Sperm Injection

CONTEXT

Elevated sperm DNA fragmentation index (DFI) is found to affect normal embryonic development, implantation and fetal development after intrauterine insemination (IUI), in vitro fertilization and intracytoplasmic sperm injection (ICSI). Estimation of DFI by terminal deoxynucleotidyl transferase-mediated fluorescent deoxy uridine nucleotide nick end labeling (TUNEL) assay was found to have a high predictive value for pregnancy after fertility treatments.

AIM

This study aims to find the effect of increased sperm DNA fragmentation by TUNEL assay on reproductive outcome after IUI and ICSI.

PRIMARY OBJECTIVE

To find the association of DFI and pregnancy rate in IUI and ICSI.

SECONDARY OBJECTIVES

To find the association of DFI with fertilization and implantation in ICSI. To find the association of DFI with miscarriage rate.

SETTINGS AND DESIGN

A prospective observational study performed at a tertiary care university teaching hospital.

SUBJECTS AND METHODS

105 male partners of infertile couple planned for IUI and ICSI underwent estimation of sperm-DFI by TUNEL assay. The treatment outcomes were compared between the DFI-positive (≥20%) and DFI-negative (<20%) groups.

STATISTICAL ANALYSIS USED

Statistical analysis was performed by SPSS version 17, Software. P < 0.05 was considered statistically significant.

RESULTS

The men with abnormal semen analysis were significantly higher in the DFI-positive group (77.15% vs. 22.85%). There was no significant difference in the pregnancy rate in IUI cycles (17.6% vs. 11.8%); but in the ICSI, the pregnancy rate was significantly reduced in the DFI-positive group (16.7% vs. 47.4%).

CONCLUSIONS

Elevated DFI significantly affects the pregnancy rate in ICSI cycles.

DNA fragmentation in concert with the simultaneous assessment of cell viability in a subfertile population: establishing thresholds of normality both before and after density gradient centrifugation

PURPOSE

TUNEL assay is the most common, direct test for sperm chromatin integrity assessment. But, lack of standardized protocols makes interlaboratory comparisons impossible. Consequently, clinical thresholds to predict the chance of a clinical pregnancy also vary with the technique adopted. This prospective study was undertaken to assess the incidence of sperm DNA fragmentation in a subfertile population and to establish threshold values of normality as compared to a fertile cohort, both before and after density gradient centrifugation in the total and vital fractions.

METHOD

Men presenting at a university hospital setup for infertility treatment. DNA damage via TUNEL assay was validated on fresh semen samples, as conventional semen parameters, to reduce variability of results.

RESULTS

Total DNA fragmentation in the neat semen was significantly higher in the subfertile group, but the vital fraction was not significantly different between the two cohorts. After gradient centrifugation, DNA fragmentation increased significantly in the total fraction of the subfertile group but decreased significantly in the vital fraction. In the fertile cohort, there was a non-significant increase in total fragmentation and in the vital fraction the trend was unclear.

CONCLUSIONS

Estimating total and vital sperm DNA fragmentation, after density gradient centrifugation, increased both the sensitivity and the specificity, thereby lowering the number of false negatives and false positives encountered. These findings provide opportunities to investigate the significance of the total and the vital fractions after different assisted reproductive technologies.

Two-dimensional planar swimming selects for high DNA integrity sperm

Selection of high-quality sperm is critical to the success of assisted reproductive technologies. Clinical screening for top sperm has long focused on sperm swimming ability when following boundaries or when fully free of constraints. In this work, we demonstrate a sperm selection approach with parallel 2 μm tall confined selection channels that prohibit rotation of the sperm head and require planar swimming. We demonstrate that a planar swimming subpopulation of sperm capable of entering and navigating these channels has DNA integrity superior to the freely-swimming motile or raw sperm populations over a wide range of semen sample qualities. The DNA integrity of the selected sperm was significantly higher than that of the corresponding raw samples for donor samples and clinical patient samples, respectively. In side-by-side testing, this method outperforms current clinical selection methods, density gradient centrifugation and swim-up, as well as sperm selected via general motility. Planar swimming represents a viable sperm selection mechanism with the potential to improve outcomes for couples and offspring.

Sperm DNA fragmentation index influences assisted reproductive technology outcome: A systematic review and meta-analysis combined with a retrospective cohort study

Studies have explored the influence of DNA damage in assisted reproductive technology (ART), but the outcome remains controversial. To determine whether sperm DNA fragmentation index (DFI) has any effect on ART outcomes, we collected detailed data regarding 1,333 IVF cycles performed at our centre, and the data of our retrospective cohort study were extracted for this meta-analysis. We searched PubMed, Web of Science, EMBASE and Google Scholar and performed a systemic review and meta-analysis. Primary meta-analysis of 10 studies comprising 1,785 couples showed that live birth rate was no significantly different between low-DFI group and high-DFI group (p > 0.05). Secondary meta-analysis of 25 studies comprising 3,992 couples showed a higher miscarriage rate in high-DFI group than in low-DFI group (RR=1.57 [1.18, 2.09], p < 0.01). Meta-analysis of eight studies comprising 17,879 embryos revealed a lower good-quality embryo rate (RR=0.65 [0.62, 0.68], p < 0.01). Meta-analysis of 23 studies comprising 6,771 cycles showed that the high-DFI group had a lower clinical pregnancy rate than low-DFI group (RR=0.85 [0.75, 0.96], p < 0.01). Heterogeneity of included studies weakened our conclusions. Our study showed that DFI has adverse effects on ART outcome. More well-designed studies exploring the association between DFI and ART outcome are desired.

Review of current guidelines for recurrent pregnancy loss: new strategies for optimal evaluation of women who may be superfertile

The current evidence-based guidelines for the evaluation of recurrent pregnancy loss recommended by the American Society for Reproductive Medicine and by the European Society of Human Reproduction and Embryology are compared and contrasted in this review. The clinical use of either of these guidelines will result in a probable diagnosis for only half of the affected patients. New strategies for a full evaluation of recurrent pregnancy loss incorporating 24- chromosome microarary on the products of conception offer more explanations for patients and caregivers. This new algorithm should decrease the use of empiric, unproven treatments. Combining the results of genetic testing on the miscarriage tissue with the conventional diagnostic tests has made it possible to explain the etiology of pregnancy loss in more than 90% of the cases. This cost-saving strategy can decrease the emotional distress and frustration for both couples and physicians when it comes to management of recurrent pregnancy loss.

Effect of Spermatic Nuclear Quality on Live Birth Rates in Intracytoplasmic Sperm Injection

Background:

Our study defines the clinical role of sperm DNA damage in the assisted reproductive technology procedure.

Aim:

To investigate if the compaction of chromatin explored added to the analysis of the sperm DNA fragmentation allows obtaining a new indicator for sperm genome quality linked to live birth rate (LBR).

Design:

This was a prospective study, undergoing 101 cycles in the intracytoplasmic sperm injection (ICSI) program.

Materials and Methods:

The sperm DNA fragmentation index (DFI) has been measured with sperm chromatin dispersion examination. The sperm decondensation index (SDI) of chromatin has been measured with aniline blue procedure; with these indexes, a new parameter has been created: DFI × SDI.

Statistical Analysis:

Pearson's correlation coefficient, Student's t-test, and Chi-square test were used. The quantitative variables were described as mean ± standard deviation. Multivariate logistic regressions were performed with live birth as outcome.

Results:

The sperm concentration, motility, and normal morphology were lower when the DFI was high (P = 0.001). The fertilization rates and the number of obtained embryos were not statistically significant different according to the DFI groups. The SDI does not appear to be linked either with the spermatic parameters or with the ICSI parameters. A low DFI seems to be a beneficial factor to obtain a live birth in ICSI procedure (P = 0.064). In case of high DFI, a high SDI allows to obtain a higher LBR than a low SDI.

Conclusion:

The DFI is a good prognostic for a delivery rate in ICSI procedure, and the SDI could be added to DFI to create a new parameter of sperm nuclear quality. This new parameter seems to be linked to LBR.