Reproductive Outcomes of Different Sperm Selection Techniques for ICSI Patients with Abnormal Sperm DNA Fragmentation: a Randomized Controlled Trial

A Narrative Review on the Sperm Selection Methods in Assisted Reproductive Technology: Out with the New, the Old Is Better?

Background: Male infertility, accounting for nearly half of infertility cases worldwide, has spurred significant research into its causes, diagnosis, and treatment strategies. Genetic abnormalities, social causes, environmental exposures, lifestyle, and further health conditions are key contributors. Methods: Essential to improving the outcomes of ART is, among other things, the selection of high-quality sperm, which requires methods that assess sperm motility, morphology, DNA integrity, and oxidative stress levels. Results: Traditional techniques such as semen analysis, swim-up, and density gradient centrifugation (DGC) are still widely used, but there is ongoing discussion regarding the limitations in detecting DNA damage and oxidative stress. Advanced methods like magnetic-activated cell sorting (MACS) and microfluidic sorting have emerged as more precise tools for selecting sperm with better genetic integrity, although they face challenges in terms of their standardization, cost, and clinical adoption. Emerging technologies such as artificial intelligence (AI) and Raman spectroscopy offer the potential for more automated, accurate sperm selection, minimizing human error and variability. However, the integration of these methods into clinical practice requires further validation through large-scale studies, including assessments of their long-term safety and cost-effectiveness. Conclusions: Future research should focus on refining sperm selection techniques, tailoring them to personalized infertility approaches, and addressing the gaps in the evidence to improve ART outcomes and patient care.

Sperm chromatin: Evaluation, epigenetic signatures and relevance for embryo development and assisted reproductive technology outcomes

Sperm chromatin is distinct from somatic cell chromatin, as a result of extensive remodeling during the final stages of spermatogenesis. In this process, the majority of histones is replaced with protamines. The chromatin is consequently highly condensed and inert, which facilitates protection of the DNA. The sperm epigenomic landscape is shaped by histone retention, histone and protamine modification, DNA methylation, and RNAs. In recent years, sperm chromatin integrity and its epigenetic marks have been increasingly studied, and the constitution of sperm chromatin is steadily being uncovered. This growing body of research prompts assessment of the frequently overlooked involvement of sperm in fertility and embryonic development. Moreover, numerous endogenous and exogenous factors are known to affect sperm chromatin, which may in turn impact the reproductive success. Concerns have been raised about the effects of assisted reproductive technology (ART) on the sperm epigenome, embryonic development and offspring health. This review examines the structure and epigenetic signatures of sperm chromatin in the context of fertility and early embryonic development. Additionally, sperm chromatin evaluation and causes of aberrant integrity are outlined. Building on the knowledge discussed in the current review, future research should aim to elucidate the intricate relationship between all aspects of sperm chromatin and embryo development. This could lead to the uncovering of new targets for treating infertility, as well as the acquisition of much needed insights into the possible reciprocal association between ART and sperm chromatin integrity.

In cases with raised sperm DNA fragmentation, can sperm selection by magnetic-activated cell sorting or testicular sperm aspiration help improve reproductive outcomes?

PURPOSE

To evaluate the efficacy of magnetic-activated cell sorting (MACS) or testicular sperm aspiration (TESA) to improve reproductive outcomes in cases with elevated sperm DNA fragmentation undergoing assisted reproduction.

METHODS

This randomized controlled trial included couples with failed IVF cycles and sperm DNA fragmentation > 30%. Sperm DNA fragmentation was assessed using the sperm chromatin structure assay (SCSA) method. Participants were randomly assigned to either the MACS or TESA group. Testicular sperm retrieval was performed for the TESA group, while MACS involved sperm selection using magnetic beads. Extended blastocyst culture, freeze all policy of blastocysts by vitrification, and frozen embryo transfer were undertaken as per clinic's standard operating protocols. Blastocyst formation rate, implantation rate, miscarriage rate, multiple pregnancy rate, and live birth rate were analyzed and compared between MACS and TESA groups.

RESULTS

There were no significant differences in female age, male age, or sperm DNA fragmentation index (DFI) between the MACS and TESA groups. The blastocyst conversion rate was slightly higher in the TESA group (39%) compared to the MACS group (32%). However, the MACS group had a higher implantation rate (50%) than the TESA group (35%). Miscarriage rates, multiple pregnancy rates, and live birth rates did not show statistically significant differences between the groups. A chi-squared test was conducted to compare categorical variables, and t-tests were done to compare continuous variables.

CONCLUSION

In cases with raised sperm DNA fragmentation, sperm selection by MACS or TESA seems to offer comparable reproductive outcomes. There seems no superiority of one intervention over the other in cases with raised sperm DNA fragmentation undergoing assisted reproduction. Both interventions seem to be beneficial for couples seeking assisted reproduction with raised sperm DNA fragmentation.

Does Testicular Sperm Improve Intracytoplasmic Sperm Injection Outcomes for Nonazoospermic Infertile Men with Elevated Sperm DNA Fragmentation? A Systematic Review and Meta-analysis

CONTEXT

For nonazoospermic infertile men with elevated sperm DNA fragmentation (SDF), it is unclear whether the use of testicular sperm for intracytoplasmic sperm injection (ICSI) may offer advantages over ejaculated sperm.

OBJECTIVE

To determine whether ICSI outcomes (fertilisation rate, pregnancy rate, miscarriage rate, and live birth rate) are better with testicular sperm than with ejaculated sperm for men with elevated SDF.

EVIDENCE ACQUISITION

We searched the Cochrane Central, EMBASE, MEDLINE, Web of Science, and Scopus databases (1946-2023) in February 2023 for relevant human comparative studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

EVIDENCE SYNTHESIS

Out of 2032 records, nine studies (more than 536 participants, mean age range 33-40.5 yr for males and 30.1-37.9 yr for females) were included in the systematic review and meta-analysis. Pooled estimates demonstrated that the pregnancy rate was significantly higher with testicular than with ejaculated sperm according to a sperm chromatin structure assay (SCSA)/sperm chromatin integrity test (SCIT) (odds ratio [OR] 2.51; p = 0.001) and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assays (OR 3.65; p = 0.005). The live birth rate was significantly higher according to SCSA/SCIT (OR 2.59; p = 0.005). There were no significant differences in the fertilisation rate or miscarriage rate.

CONCLUSIONS

Although significant improvements in pregnancy and live birth rates were observed with testicular sperm, the strength of findings is limited by availability and quality of evidence, both of which undermine recommendations for clinical practice. Standardised randomised controlled trials are needed to definitively determine whether the use of testicular sperm improves ISCI outcomes for men with high SDF. Until such evidence exists, ICSI after testicular sperm extraction or aspiration should not be routinely performed.

PATIENT SUMMARY

Our review showed that for infertile men with a high level of DNA damage in their sperm, use of sperm extracted from the testicles may give better results than ejaculated sperm for a particular IVF (in vitro fertilisation) technique. However, there is a lack of high-quality data.

Good practice recommendations on add-ons in reproductive medicine†

STUDY QUESTION

Which add-ons are safe and effective to be used in ART treatment?

SUMMARY ANSWER

Forty-two recommendations were formulated on the use of add-ons in the diagnosis of fertility problems, the IVF laboratory and clinical management of IVF treatment.

WHAT IS KNOWN ALREADY

The innovative nature of ART combined with the extremely high motivation of the patients has opened the door to the wide application of what has become known as 'add-ons' in reproductive medicine. These supplementary options are available to patients in addition to standard fertility procedures, typically incurring an additional cost. A diverse array of supplementary options is made available, encompassing tests, drugs, equipment, complementary or alternative therapies, laboratory procedures, and surgical interventions. These options share the common aim of stating to enhance pregnancy or live birth rates, mitigate the risk of miscarriage, or expedite the time to achieving pregnancy.

STUDY DESIGN, SIZE, DURATION

ESHRE aimed to develop clinically relevant and evidence-based recommendations focusing on the safety and efficacy of add-ons currently used in fertility procedures in order to improve the quality of care for patients with infertility.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ESHRE appointed a European multidisciplinary working group consisting of practising clinicians, embryologists, and researchers who have demonstrated leadership and expertise in the care and research of infertility. Patient representatives were included in the working group. To ensure that the guidelines are evidence-based, the literature identified from a systematic search was reviewed and critically appraised. In the absence of any clear scientific evidence, recommendations were based on the professional experience and consensus of the working group. The guidelines are thus based on the best available evidence and expert agreement. Prior to publication, the guidelines were reviewed by 46 independent international reviewers. A total of 272 comments were received and incorporated where relevant.

MAIN RESULTS AND THE ROLE OF CHANCE

The multidisciplinary working group formulated 42 recommendations in three sections; diagnosis and diagnostic tests, laboratory tests and interventions, and clinical management.

LIMITATIONS, REASONS FOR CAUTION

Of the 42 recommendations, none could be based on high-quality evidence and only four could be based on moderate-quality evidence, implicating that 95% of the recommendations are supported only by low-quality randomized controlled trials, observational data, professional experience, or consensus of the development group.

WIDER IMPLICATIONS OF THE FINDINGS

These guidelines offer valuable direction for healthcare professionals who are responsible for the care of patients undergoing ART treatment for infertility. Their purpose is to promote safe and effective ART treatment, enabling patients to make informed decisions based on realistic expectations. The guidelines aim to ensure that patients are fully informed about the various treatment options available to them and the likelihood of any additional treatment or test to improve the chance of achieving a live birth.

STUDY FUNDING/COMPETING INTEREST(S)

All costs relating to the development process were covered from ESHRE funds. There was no external funding of the development process or manuscript production. K.L. reports speakers fees from Merck and was part of a research study by Vitrolife (unpaid). T.E. reports consulting fees from Gynemed, speakers fees from Gynemed and is part of the scientific advisory board of Hamilton Thorne. N.P.P. reports grants from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare, speakers fees from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare. S.R.H. declares being managing director of Fertility Europe, a not-for-profit organization receiving financial support from ESHRE. I.S. is a scientific advisor for and has stock options from Alife Health, is co-founder of IVFvision LTD (unpaid) and received speakers' fee from the 2023 ART Young Leader Prestige workshop in China. A.P. reports grants from Gedeon Richter, Ferring Pharmaceuticals and Merck A/S, consulting fees from Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos and Merck A/S, speakers fees from Gedeon Richter, Ferring Pharmaceuticals, Merck A/S, Theramex and Organon, travel fees from Gedeon Richter. The other authors disclosed no conflicts of interest.

DISCLAIMER

This Good Practice Recommendations (GPRs) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation.ESHRE GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or bedeemedinclusive of all proper methods of care, or be exclusive of other methods of care reasonably directed to obtaining the same results.Theydo not replace the need for application of clinical judgement to each individual presentation, or variations based on locality and facility type.Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring, of any of the included technologies by ESHRE.

Unraveling the Impact of Sperm DNA Fragmentation on Reproductive Outcomes

In recent years, there has been a growing interest in identifying subcellular causes of male infertility, and sperm DNA fragmentation (SDF) research has been at the forefront of this focus. DNA damage can occur during spermatogenesis due to faulty chromatin compaction or excessive abortive apoptosis. It can also happen as sperm transit through the genital tract, often induced by oxidative stress. There are several methods for SDF testing, with the sperm chromatin structure assay, terminal deoxynucleotidyl transferase d-UTI nick end labeling (TUNEL) assay, comet assay, and sperm chromatin dispersion test being the most commonly used. Numerous studies strongly support the negative impact of SDF on male fertility potential. DNA damage has been linked to various morphological and functional sperm abnormalities, ultimately affecting natural conception and assisted reproductive technology outcomes. This evidence-based review aims to explore how SDF influences male reproduction and provide insights into available therapeutic options to minimize its detrimental impact.

Sperm DNA fragmentation testing in clinical management of reproductive medicine

Background

Approximately 8%-12% of couples worldwide face infertility, with infertility of individuals assigned male at birth (AMAB) contributing to at least 50% of cases. Conventional semen analysis commonly used to detect sperm abnormalities is insufficient, as 30% of AMAB patients experiencing infertility show normal results in this test. From a genetic perspective, the assessment of sperm DNA fragmentation (SDF) is important as a parameter of sperm quality.

Methods

In this narrative study, we review and discuss pathophysiological causes, DNA repair mechanisms, and management of high SDF. We then summarize literature exploring the association between SDF and reproductive outcomes.

Main Findings

Recent systematic reviews and meta-analyses have revealed a significant association between high SDF in AMAB individuals and adverse reproductive outcomes including embryo development, natural conception, intrauterine insemination, and in vitro fertilization. However, the association with live birth rates and pregnancy rates following intracytoplasmic injection remains inconclusive. The disparities among quantitative assays, inconsistent reference range values, absent high-quality prospective clinical trials, and clinical heterogeneity in AMAB patients with elevated SDF represent the main limitations affecting SDF testing.

Conclusion

The evaluation and management of SDF plays an important role in a subset of AMAB infertility, but widespread integration into clinical guidelines will require future high-quality clinical trials and assay standardization.

Sperm selection with Annexin-V coated polystrene bead technique (APB-Tech): A novel and reliable method for the microscopic selection of viable and non-apoptotic sperm to be used for intracytoplasmic sperm injection

Infertility is a growing health problem that affects 20% of couples who want to conceive. 'Intracytoplasmic sperm injection' (ICSI) is a commonly used assisted reproduction treatment technique that offers the couples to overcome a wide variety of infertility reasons, including female, male and unexplained infertility. A crucial step in ICSI is choosing the correct sperm with the highest potential to form a healthy embryo and thus a healthy offspring. The sperm selection strategies aim to obtain a sperm population with better motility and morphology, which are insufficient to predict a sperm's reproductive potential. The elimination of apoptotic sperms, which is shown to be higher in infertile males and which is shown to affect embryo development and reproductive cohort significantly should also be included in the selection strategies. Among all sperm selection methods, there are only a few which can eliminate apoptotic sperm, but because they need extra types of equipments, a long training period, and high costs, they couldn't find place in the most commonly used techniques in an IVF lab. Selecting the non-apoptotic sperm cells will help us choose a sperm that is more likely to be chosen by the natural selection mechanisms and thus will help to mimic the natural conception more. The study aimed to develop a novel, easy and a harmless individual sperm selection technique to enable choosing non-apoptotic viable sperm cells via light microscopy without any need for extra equipment, education and cost to be used for ''ICSI'. The technique is based on the binding ability of Annexin-V covered polystrene beads to the externalized phosphatidylserine at the outer leaflet of an apoptotic sperm's plasma membrane. After Annexin-V covered polystyrene beads were prepared, beads obtained were attached to BALB-c mice sperm, and the technique is optimized to obtain the most efficient attachment conditions. The results are then compared with the results of four well-known reliable apoptosis detection techniques to test the validity and sperm survival test to test the toxicity of the technique. The method is proven to be '''reliable' by comparing it with the results of well-known techniques, including TUNEL and SCSA (sperm chromatin structure assay), and '''safe' by showing its non-toxicity via sperm survival test (SST). In addition, the method enables the selection of sperm cells more closer to naturally-chosen ones from a pool of sperm that should not be allowed to be randomly chosen during microinjection. To date, it was impossible to distinguish a non-apoptotic sperm without harming it or without needing additional equipment other than a routine IVF lab and extra training other than routine andrology work. The technique is named as 'Annexin-V coated polystyrene bead technique (APB-Tech)'. Based on our results, further studies on APB-Tech should be focused on the possible improvement of ICSI outcomes and, thus, success rates.

Clinical study of Wuwei Fuzheng Yijing formula in the treatment of sperm DNA damage in male infertility: A study protocol for a randomized controlled trial

BACKGROUND

The incidence of male infertility is increasing in recent years, and the semen routine examination of some patients is normal, but the semen pathological examination shows that the sperm DNA fragmentation index (DFI) is high, and the patients' clinical manifestations are infertility or recurrent abortion of their spouses. At present, there is no special treatment for male infertility caused by high DFI, and traditional Chinese medicine compound prescription shows potential value in the treatment of male infertility. Wuwei Fuzheng Yijing formula (WFY) is an effective prescription for the treatment of sperm DNA damage in male infertility, but there is no strict clinical trial to support its application. Therefore, we designed a randomized controlled trial to evaluate the efficacy and safety of WFY in patients with sperm DNA damage in male infertility.

METHODS

In this randomized controlled study, 100 patients who met the inclusion criteria were randomly divided into WFY group and levocarnitine oral solution group. The treatment period was 12 weeks. The main observation index was sperm DFI, and the secondary observation index was sperm concentration, motility, survival rate, and TCM syndrome score. Safety observation indicators will include electrocardiogram, blood tests (including blood routine tests, liver and renal function), routine urine tests, and routine stool tests. All results were evaluated at the 4th and 8th week of the baseline, and the end of treatment.

DISCUSSION

This study will provide a basis for the efficacy and safety of WFY in the treatment of sperm DNA damage in male infertility with spleen and kidney qi deficiency and blood stasis.

Effect of Sperm Selection by Magnetic-Activated Cell Sorting in D-IUI: A Randomized Control Trial

Clinical outcome in assisted reproduction techniques (ARTs) is mainly influenced by the quality of gametes used. It is known that a high percentage of sperm DNA fragmentation (DNAf) decreases the success of ART clinical results. Therefore, techniques such as magnetic-activated cell sorting (MACS) help to improve results in cases of patients with a high percentage of DNAf. Cryopreservation of sperm in donor intrauterine insemination (D-IUI) treatments increases sperm DNAf, so patients using these sperm samples can benefit from using this technique. This prospective randomized national multicenter study analyzed clinical outcomes of 181 D-IUI treatments. MACS was performed after density gradient centrifugation (DGC) in 90 thawed semen donor samples (MACSG), whereas only DGC was performed in 91 thawed semen donor samples (CG). To our knowledge, this is the first study analyzing the effect of MACS on D-IUI cycles. Our results show no significant differences in gestation, live birth, or miscarriage rates between the two groups. We believe that further studies with a larger sample size are needed to evaluate the application of MACS in combination with standard IUI donor sperm preparations in fertility clinics.