A microfluidic sperm-sorting device reduces the proportion of sperm with double-stranded DNA fragmentation

Quantifying the association of sperm DNA fragmentation with assisted reproductive technology outcomes: An umbrella review

BACKGROUND

Systematic reviews and meta-analyses are instrumental in shaping clinical practice. However, their findings can sometimes be marred by discrepancies and potential biases, thereby diluting the strength of the evidence presented. Umbrella reviews serve to comprehensively assess and synthesise these reviews, offering a clearer insight into the quality of the evidence presented. In the context of the relationship between sperm DNA fragmentation (SDF) and assisted conception outcomes, there is a divergence in the literature. Some reviews suggest a clear cause-and-effect linkage, whereas others present conflicting or inconclusive results.

OBJECTIVES

In this umbrella review we aimed to synthesise the evidence collated in systematic reviews and meta-analyses summarising the association of SDF with assisted reproductive technology (ART) outcomes.

SEARCH STRATEGY

After preregistration (https://doi.org/10.17605/OSF.IO/6JHDP), we performed a comprehensive search of the PubMed, Scopus, Cochrane Library, Web of Science and Embase databases. We conducted a search for systematic reviews on the association between SDF and ART without any restrictions on language or publication date.

SELECTION CRITERIA

Systematic reviews and meta-analyses assessing the association between SDF and ART outcomes were eligible.

DATA COLLECTION AND ANALYSIS

We assessed the quality of the included reviews using AMSTAR 2 and ROBIS, and determined the degree of overlap of primary studies between reviews estimating the corrected covered area (CCA), adjusted for structural missingness. We evaluated the most recent reviews assessing the association of SDF with live birth, pregnancy, miscarriage, implantation, blastulation and fertilisation. The synthesis of evidence was harmonised across all included quantitative syntheses, re-estimating the odds ratio (eOR) in random-effects meta-analyses with 95% confidence intervals (95% CIs) and 95% prediction intervals (95% PIs). We categorised the evidence strength into convincing, highly suggestive, suggestive, weak or nonsignificant, according to the meta-analysis re-estimated P-value, total sample size, I2 statistic for heterogeneity, small study effect, excess significance bias and the largest study significance.

MAIN RESULTS

We initially captured and screened 49 332 records. After excluding duplicate and ineligible articles, 22 systematic reviews, 15 of which were meta-analyses, were selected. The 22 reviews showed a moderate degree of overlap (adjusted CCA 9.2%) in their included studies (overall n = 428, with 180 unique studies). The 15 meta-analyses exhibited a high degree of overlap (adjusted CCA = 13.6%) in their included studies (overall n = 274, with 118 unique studies). AMSTAR 2 categorised the quality of evidence in 18 reviews as critically low and the quality of evidence in four reviews as low. ROBIS categorised all the reviews as having a high risk of bias. The re-estimated results showed that the association of SDF with live birth was weak in one and nonsignificant in four meta-analyses. Similarly, the association of SDF with pregnancy, miscarriage, implantation, blastulation and fertilisation was also weak or nonsignificant. The association of high SDF with different ART outcomes was also weak or nonsignificant for different interventions (IVF, ICSI and IUI) and tests.

CONCLUSIONS

This umbrella review did not find convincing or suggestive evidence linking SDF with ART outcomes. Caution should be exercised in making any claims, policies or recommendations concerning SDF.

Advanced Sperm Selection Techniques for Assisted Reproduction

Male infertility accounts for approximately 40% of infertility cases. There are many causes of male infertility, including environmental factors, age, lifestyle, infections, varicocele, and cancerous pathologies. Severe oligozoospermia, cryptozoospermia, and azoospermia (obstructive and non-obstructive) are identified as severe male factor infertility, once considered conditions of sterility. Today, in vitro fertilization (IVF) techniques are the only treatment strategy in cases of male factor infertility for which new methodologies have been developed in the manipulation of spermatozoa to achieve fertilization and increase success rates. This review is an update of in vitro manipulation techniques, in particular sperm selection, emphasizing clinical case-specific methodology. The success of an IVF process is related to infertility diagnosis, appropriate choice of treatment, and effective sperm preparation and selection. In fact, selecting the best spermatozoa to guarantee an optimal paternal heritage means increasing the blastulation, implantation, ongoing pregnancy and live birth rates, resulting in the greater success of IVF techniques.

The impact of microfluidics sperm processing on blastocyst euploidy rates compared with density gradient centrifugation: a sibling oocyte double-blinded prospective randomized clinical trial

OBJECTIVE

To compare the euploidy rates among blastocysts created from sibling oocytes injected with sperm and processed using microfluidics or density gradient centrifugation.

DESIGN

Sibling oocyte randomized controlled trial.

SETTING

Single university-affiliated infertility practice.

PATIENTS

A total of 106 patients aged 18-42 years undergoing fresh in vitro fertilization treatment cycles with preimplantation genetic testing between January 2021 and April 2022 contributed 1,442 mature oocytes, which were injected with sperm and processed using microfluidics or density gradient centrifugation.

INTERVENTION(S)

The sperm sample is divided and processed using a microfluidics device and density gradient centrifugation for injection into sibling oocytes.

MAIN OUTCOME MEASURE(S)

The primary outcome was the embryo euploidy rate. Secondary outcomes included fertilization, high-quality blastulation, and ongoing pregnancy rates.

RESULT(S)

The blastocyst euploidy rate per mature oocyte was not significantly different in the study group compared with the control group (22.9% vs. 20.5%). The blastocyst euploidy rate per biopsied embryo was also similar between the 2 groups (53.0% vs. 45.7%). However, the fertilization rate per mature oocyte injected was found to be significantly higher in the study group compared with the control group (76.0% vs. 69.9%). The high-quality blastulation rate per mature oocyte injected was similar between the 2 groups, as was the total number of embryos frozen. There were no differences in the number of participants with no blastocysts for biopsy or the number of participants with no euploid embryos between the 2 groups. Among the male factor infertility and recurrent pregnancy loss subgroups, there were no differences in euploidy rates, fertilization rates, blastulation rates, or total numbers of blastocysts frozen, although the study was underpowered to detect these differences. Seventy-seven patients underwent frozen embryo transfer; there were no significant differences in pregnancy outcomes between the 2 groups.

CONCLUSION(S)

Microfluidics processing did not improve embryo euploidy rates compared with density gradient centrifugation in this sibling oocyte study, although fertilization rates were significantly higher.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04744025.

Sperm Preparation with Microfluidic Sperm Sorting Chip May Improve Intracytoplasmic Sperm Injection Outcomes Compared to Density Gradient Centrifugation

Does sperm preparation using the FERTILE PLUS™ Sperm Sorting Chip improve fertilization rates, blastocyst formation, utilization, and euploidy rates in patients undergoing intracytoplasmic sperm injection (ICSI), compared with density gradient centrifugation (DGC)? A single-cohort, retrospective data review including data from 53 couples who underwent ICSI cycles within a 12-month period. For each couple, the two closest, consecutive cycles were identified, where one used the standard technique of sperm preparation (DGC) and the subsequent used FERTILE PLUS™, therefore, couples acted as their own controls. Paired samples t-test was used to compare means for the outcomes (fertilization, blastocyst formation, utilization, and euploidy rates). Binary logistic regression analysis assessed the relationship between female age, the presence of male factor infertility, and euploidy rates. Blastocyst, utilization, and euploidy rates were significantly higher for cycles using FERTILE PLUS™ compared to DGC (76% vs 56%, p = 0.002; 60% vs 41%, p = 0.005, and 40% vs 20%, p = 0.001, respectively). Although there was an increase in fertilization rates for cycles using FERTILE PLUS™, this was not significant (72% vs 68%, p = 0.449). The euploidy rates of females ≤ 35 years were significantly increased when the FERTILE PLUS™ sperm preparation method was used, compared to the older age group (OR 2.31, p = 0.007). No significant association was found between the presence or absence of male factor infertility and euploidy rates between the two cycles. This study provides tentative evidence that the FERTILE PLUS™ microfluidic sorting device for sperm selection can improve blastocyst formation, utilization, and euploidy rates following ICSI in comparison to the DGC method.

Microfluidic sperm sorting selects a subpopulation of high-quality sperm with a higher potential for fertilization

STUDY QUESTION

Is a microfluidic sperm sorter (MSS) able to select higher quality sperm compared to conventional methods?

SUMMARY ANSWER

The MSS selects sperm with improved parameters, lower DNA fragmentation, and higher fertilizing potential.

WHAT IS KNOWN ALREADY

To date, the few studies that have compared microfluidics sperm selection with conventional methods have used heterogeneous study population and have lacked molecular investigations.

STUDY DESIGN, SIZE, DURATION

The efficiency of a newly designed MSS in isolating high-quality sperm was compared to the density-gradient centrifugation (DGC) and swim-up (SU) methods, using 100 semen samples in two groups, during 2023-2024.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Semen specimens from 50 normozoospermic and 50 non-normozoospermic men were sorted using MSS, DGC, and SU methods to compare parameters related to the quality and fertilizing potential of sperm. The fertilizing potential of sperm was determined by measurement of phospholipase C zeta (PLCζ) and post-acrosomal sheath WW domain-binding protein (PAWP) expression using flow cytometry, and the chromatin dispersion test was used to assess sperm DNA damage.

MAIN RESULTS AND THE ROLE OF CHANCE

In both normozoospermic and non-normozoospermic groups, the MSS-selected sperm with the highest progressive motility, PLCζ positive expression and PLCζ and PAWP fluorescence intensity the lowest non-progressive motility, and minimal DNA fragmentation, compared to sperm selected by DGC and SU methods (P < 0.05).

LIMITATION, REASONS FOR CAUTION

The major limitations of our study were the low yield of sperm in the MSS chips and intentional exclusion of severe male factor infertility to yield a sufficient sperm count for molecular experiments; thus testing with severe oligozoospermic semen and samples with low count and motility is still required. In addition, due to ethical considerations, at present, it was impossible to use the sperm achieved from MSS in the clinic to assess the fertilization rate and further outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Our research presents new evidence that microfluidic sperm sorting may result in the selection of high-quality sperm from raw semen. This novel technology might be a key to improving clinical outcomes of assisted reproduction in infertile patients.

STUDY FUNDING/COMPETING INTEREST(S)

The study is funded by the Iran University of Medical Sciences and no competing interest exists.

TRIAL REGISTRATION NUMBER

N/A.

Does microfluidic sperm selection improve clinical pregnancy and miscarriage outcomes in assisted reproductive treatments? A systematic review and meta-analysis

BACKGROUND

The microfluidic sperm selection (MFSS) device has emerged as a promising adjunct in assisted reproduction treatments (ART). It employs mechanisms of biomimicry based on the microanatomy of the female reproductive tract through strategies like chemotaxis and rheotaxis. Numerous studies assert improvements in ART outcomes with the use of MFSS, often attributed to the theoretical reduction in sperm DNA damage compared to other techniques. However, these attributed benefits lack validation through large-scale clinical trials, and there is no significant evidence of enhanced assisted reproductive treatments (ART) outcomes.

OBJECTIVE

To evaluate whether the utilization of MFSS enhances clinical pregnancy results and abortion outcomes in couples undergoing ART compared to standard sperm selection techniques for Intracytoplasmic Sperm Injection (ICSI). We also assessed laboratory outcomes as a supplementary analysis.

SEARCH METHODS

We conducted searches across databases including PubMed, NIH, LILACS, CENTRAL, Crossref, Scopus, and OpenAlex. A total of 1,255 records were identified. From these, 284 duplicate records were eliminated, and an additional 895 records were excluded due to their association with patent applications, diagnostic tests, forensic analyses, or irrelevance to the research focus. Among the initially eligible 76 studies, 63 were excluded, encompassing abstracts, studies lacking adequate control groups, and ongoing clinical trials. Ultimately, 13 studies were selected for inclusion in the ensuing meta-analysis.

RESULTS

Regarding clinical pregnancy, we assessed a total of 868 instances of clinical pregnancies out of 1,646 embryo transfers. Regarding miscarriage, we examined 95 cases of pregnancy loss among the 598 confirmed clinical pregnancies in these studies.

CONCLUSION

The utilization of MFSS demonstrates marginal positive outcomes compared to standard sperm selection techniques, without statistical significance in any of the analyses.

BROADER IMPLICATIONS

This study conducted the first meta-analysis to evaluate clinical pregnancy rates, miscarriage rates, and laboratory results associated with the use of MFSS compared to standard sperm selection techniques. We have also listed potentially eligible studies for future inclusion. It's important to emphasize the need for multicenter studies with standardized parameters to attain a more robust clarification of this issue.

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.

Surgically retrieved spermatozoa for ICSI cycles in non-azoospermic males with high sperm DNA fragmentation in semen

Intracytoplasmic sperm injection (ICSI) using surgically retrieved spermatozoa outside the classic context of azoospermia has been increasingly used to overcome infertility. The primary indications include high levels of sperm DNA damage in ejaculated spermatozoa and severe oligozoospermia or cryptozoospermia, particularly in couples with ICSI failure for no apparent reason. Current evidence suggests that surgically retrieved spermatozoa for ICSI in the above context improves  outcomes, mainly concerning pregnancy and miscarriage rates. The reasons are not fully understood but may be related to the lower levels of DNA damage in spermatozoa retrieved from the testis compared with ejaculated counterparts. These findings are consistent with the notion that excessive sperm DNA damage  can be a limiting factor responsible for the failure to conceive. Using testicular in preference of low-quality ejaculated spermatozoa bypasses post-testicular sperm DNA damage caused primarily by oxidative stress, thus increasing the likelihood of oocyte fertilization by genomically intact spermatozoa. Despite the overall favorable results, data remain limited, and mainly concern males with confirmed sperm DNA damage in the ejaculate. Additionally, information regarding the health of ICSI offspring resulting from the use of surgically retrieved spermatoa of non-azoospermic males is still lacking. Efforts should be made to improve the male partner's reproductive health for safer ICSI utilization. A comprehensive andrological evaluation aiming to identify and treat the underlying male infertility factor contributing to sperm DNA damage is essential for achieving this goal.

Future of Male Infertility Evaluation and Treatment: Brief Review of Emerging Technology

Over the past few decades, there have been significant advances in male infertility, particularly in the development of novel diagnostic tools. Unfortunately, there remains a substantial number of patients that remain infertile despite these improvements. In this review, we take heed of the emerging technologies that will shape the future of male infertility diagnosis, evaluation and treatment. Improvement in computer-assisted semen analyses and portability allow males to obtain basic semen parameters from the comfort of their home. Additionally, breakthrough ultrasound technology allows for preoperative prediction of potential areas of spermatogenesis within the testes, high-resolution optics permits better visualization during microdissection testicular sperm extraction (mTESE), and artificial intelligence improves sperm selection and identification.

Embryologic outcomes among patients using a microfluidics chip compared to density gradient centrifugation to process sperm: a paired analysis

PURPOSE

To evaluate embryologic outcomes among paired IVF cycles in which a microfluidics chip was utilized compared to density gradient centrifugation for sperm processing.

METHODS

This was a retrospective cohort study of 88 paired IVF cycles from patients aged 18-44 years at a university-affiliated IVF center. Fresh cycles from patients undergoing ICSI with sperm processed by a microfluidics chamber (microfluidics cycles) were compared to the same patients' previous ICSI cycles in which sperm was processed via density gradient centrifugation (control cycles). The primary outcome was the high-quality blastulation rate.

RESULTS

High-quality blastulation rate per oocyte retrieved was significantly higher in the microfluidics group compared to the control group (21.1% versus 14.5%, p < 0.01) as was the blastulation rate per 2PN (42.7% versus 30.8%, p < 0.01). Fertilization rates were significantly higher in the microfluidics group. The euploidy rate per oocyte retrieved was significantly higher in the microfluidics group compared with the control group (8.5% versus 4.3%, p = 0.04), while the euploidy rate per embryo biopsied was comparable (32.6% versus 21.8%, p = 0.09). In patients with male factor infertility, the high-quality blastulation rate was similar between the control and microfluidics cycles. There was a significantly higher blastulation rate among microfluidics cycles in patients without a diagnosis of male factor infertility (p < 0.01).

CONCLUSION

In this study, several embryologic outcomes, including fertilization rate, high-quality blastulation rate, and euploidy rate, were significantly higher in the microfluidics group compared to the control group. Microfluidics sperm processing may be a way to improve embryologic outcomes.

Sperm Selection and Embryo Development: A Comparison of the Density Gradient Centrifugation and Microfluidic Chip Sperm Preparation Methods in Patients with Astheno-Teratozoospermia

In recent years, microfluidic chip-based sperm sorting has emerged as an alternative tool to centrifugation-based conventional techniques for in vitro fertilization. This prospective study aims to compare the effects of density gradient centrifugation and microfluidic chip sperm preparation methods on embryo development in patient populations with astheno-teratozoospermia. In the study, the semen samples of the patients were divided into two groups for preparation with either the microfluidic or density gradient methods. Selected spermatozoa were then used to fertilize mature sibling oocytes and the semen parameters and embryo development on days 3 and 5 were assessed. While the density gradient group was associated with a higher sperm concentration, motility (progressive and total) was significantly higher in the microfluidic chip group. No significant differences were observed in the fertilization rates or grade 1 (G1) and grade 2 (G2) proportions of the third-day embryos. Furthermore, while the proportions of the poor, fair and good blastocysts on day 5 did not differ significantly, excellent blastocysts (indicating high-quality embryos) were observed in a significantly higher proportion of the microfluidic chip group. When compared to the classical density gradient method, the microfluidic chip sperm preparation yielded sperm with higher motility and higher quality blastocysts at day 5; in patients with astheno-teratozoospermia.