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

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2025 Update on Male Infertility

BACKGROUND AND OBJECTIVE

To present a summary of the updated 2025 European Association of Urology (EAU) Guidelines on Sexual and Reproductive Health (SRH) on male infertility, providing practical recommendations on the clinical work-up with a focus on diagnosis, treatment and follow-up.

METHODS

For the 2025 SRH guidelines, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of a thorough urological assessment of all men seeking medical help for fertility problems to ensure appropriate treatment. The guidelines also stress the clinical relevance of a parallel investigation of the female partner during the diagnostic and management work-up of the infertile couple, to promote shared-decision making in terms of timing and therapeutic strategies. Furthermore, the guidelines recommend to counsel all infertile men and men with abnormal semen parameters on the associated health risks. Key changes in the male infertility guidelines for 2025 include: the addition of two new sections addressing exome sequencing and probiotic treatment; and significant update of the evidence base and recommendations for the diagnostic work-up of male infertility.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2025 SHR guidelines offers valuable insights into the diagnosis, classification, treatment and follow-up of male factor infertility and are designed for effective integration into clinical practice.

Global Andrology Forum Clinical Guidelines on the Relevance of Sperm DNA Fragmentation in Reproductive Medicine

PURPOSE

To evaluate the evidence on sperm DNA fragmentation (SDF) and its clinical applications in reproductive medicine, highlighting benefits, limitations, and guidelines for its use to assist clinicians in objective decision-making.

MATERIALS AND METHODS

A multidisciplinary team of clinicians and reproductive experts from the Global Andrology Forum (GAF) reviewed the latest evidence on SDF, covering indications, testing methods, recurrent pregnancy loss, varicocele and its repair, assisted reproductive technologies (ART), treatment of associated conditions, antioxidant therapy, and sperm selection for ART. Expert statements and recommendations were developed and graded with the GRADE system using a modified Delphi process.

RESULTS

Based on the GAF surveys, systematic reviews, and meta-analyses related to SDF, 52 experts introduced and scored 24 statements and recommendations using the GRADE system. Of these, 87.5% (21/24) achieved strong ratings, reflecting broad consensus, while 12.5% (3/24) were rated weak. The guidelines provide evidence-based recommendations for clinical scenarios, including the role of SDF in infertility, recurrent pregnancy loss, and ART outcomes.

CONCLUSIONS

While there is growing interest and evidence regarding the clinical benefit of SDF testing and its utility in managing male infertility, significant gaps in the literature limit its routine use in clinical practice. The guidelines offer a structured framework for integrating SDF testing into male infertility management, emphasizing a tailored approach based on individual clinical scenarios. Clinicians must balance the benefits and limitations of SDF testing and antioxidant treatment to optimize care in reproductive medicine. These guidelines are critical for advancing evidence-based practices in male infertility management.

Superior Live Birth Rates, Reducing Sperm DNA Fragmentation (SDF), and Lowering Miscarriage Rates by Using Testicular Sperm Versus Ejaculates in Intracytoplasmic Sperm Injection (ICSI) Cycles from Couples with High SDF: A Systematic Review and Meta-Analysis

This study aimed to compare sperm DNA fragmentation (SDF) levels between ejaculate and testicular sperm and evaluate clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles using testicular sperm (T-ICSI) versus ejaculate sperm (E-ICSI) in males with high ejaculate SDF, prior ICSI failures, or severe male infertility. A systematic review of major databases and a subsequent meta-analysis were performed to compare clinical outcomes in men with high SDF, oligozoospermia, or prior ICSI failures undergoing T-ICSI or E-ICSI. Thirteen studies met the inclusion criteria. Outcomes analyzed included SDF levels, fertilization rate (FR), clinical pregnancy rate (CPR), live birth rate (LBR) per embryo transfer (ET), and miscarriage rate (MR) per pregnancy. The mean difference (MD) and odds ratio (OR) were calculated for each outcome. Paired assessments of SDF showed significantly lower levels in testicular sperm compared to ejaculated sperm (MD = -25.42 [-31.47, -17.30], p < 0.00001). While no significant difference in FR was observed in T-ICSI cycles overall (OR = 0.94 [0.74, 1.20]), a subgroup analysis revealed significantly higher FR with E-ICSI in men with oligozoospermia and no prior ICSI failures (OR = 0.61 [0.52, 0.71], p < 0.00001). CPR was significantly higher in T-ICSI cycles (OR = 2.13 [1.35, 3.36], p < 0.001; n = 540 ET), along with a significantly lower MR (OR = 0.31 [0.14, 0.70], p = 0.004; n = 35) and increased LBR (OR = 2.40 [1.32, 4.36], p = 0.004; n = 446 ET). In conclusion, using testicular sperm in cases of elevated ejaculate SDF, oligozoospermia, or prior failed ICSI cycles enhances the selection of sperm with lower DNA damage, leading to improved pregnancy rates, reduced miscarriage rates, and higher live birth rates. However, the studies included were rated as having a moderate to serious risk of bias. Further well-designed randomized controlled trials are necessary to confirm these findings with stronger evidence.

The paternal clock: Uncovering the consequences of advanced paternal age on sperm DNA fragmentation

The objective of the study was to investigate the relationship between advanced paternal age and sperm DNA fragmentation (SDF) levels, specifically identifying the age at which a significant increase in SDF occurs. This is a retrospective cohort study involving 4250 consecutive semen samples from patients presenting for infertility evaluation. Patients were stratified into seven age groups: < 26 (n = 36; 0.8 %), 26-30 (n = 500; 11.8 %), 31-35 (n = 1269; 29.9 %), 36-40 (n = 1268; 29.8 %), 41-45 (n = 732; 17.2 %), 46-50 (n = 304; 7.2 %), > 50 (n = 141; 3.3 %). The main outcome measures included comparing mean SDF levels throughout different age groups and assessing the prevalence of normal, intermediate, and high SDF among the age groups. A positive correlation was observed between paternal age and SDF (r = 0.17, p < 0.001). SDF remained relatively constant until the age of 35 but increased significantly beyond age 35. Mean SDF levels in the older age groups (36-40, 41-45, 46-50, and >50 years) were significantly higher than in the younger age groups (<26, 26-30, and 31-35 years) (p < 0.001). The prevalence of normal SDF was highest among the younger age groups, whereas the prevalence of high SDF was highest among the older age groups. Interestingly, the prevalence of intermediate SDF was relatively constant throughout the age groups (ranging between 29.8 % to 37.2 %). The increase in SDF after the age of 35 highlights the importance of considering male age in infertility evaluations. Assessing SDF in men over the age of 35 is crucial in couples seeking to conceive.

Impact of short abstinence versus testicular sperm on sperm DNA fragmentation: a systematic review and meta-analysis

PURPOSE

Optimal sperm DNA integrity is essential for fertilization and embryo health. Research indicates that testicular sperm (TS), obtained via TESA or TESE, typically show lower sperm DNA fragmentation (SDF) than ejaculated sperm after standard abstinence. Shortening abstinence to less than 2 days might reduce SDF, offering a less invasive and more cost-effective alternative to surgical sperm retrieval. Yet, no studies have directly compared the efficacy of shorter abstinence against TS extraction for lowering SDF. Our meta-analysis aims to address this gap by comparing SDF levels in TS to those in ejaculated sperm after a short abstinence period.

METHODS

Meta-analysis of 16 randomized controlled and prospective observational studies included 4 on TS and 12 on short abstinence ejaculation. The meta-analysis followed MOOSE guidelines, scrutinizing databases including Cochrane Library, Web of Science, Embase, MEDLINE(R), and PUMBED up to November 16, 2023. The analysis was conducted using RevMan. The observational studies' methodological quality was assessed using the Newcastle-Ottawa Scale, and the overall evidence quality was evaluated following the GRADE criteria. To compare short ejaculation duration and TS (are not directly compared in the literature) for SDF levels, we analyzed relevant data from studies of each method. We adjusted the participant numbers in the TS group by 1/3 and included each TS study three times, to perform a comparison against the short duration studies which were in a ratio of 1:3. This approach maintained an unaltered cumulative subject count for the meta-analysis of TS studies.

RESULTS

A total of 641 patients were included, comprising 120 and 521 patients with SDF measurements following TS and ejaculation after a short abstinence period, respectively. The studies had varied inclusion criteria, with not all patients having an initial elevated SDF. Some studies had incomplete details on age and other demographics. However, the mean ± SD age of 93 TS patients was 38.15 ± 5.48 years vs. 37.7 ± 6.0 years of 444 short abstinence patients, demonstrating no significant difference (P = 0.544). Short abstinence durations ranged from 1 to 48 h. Diverse DNA fragmentation tests were used: TUNEL assay in three testicular sperm studies, SCD assay in one, and in the short abstinence group, four used TUNEL and six used SCD assays, along with one each using SCSA and Halosperm. The mean ± SD SDF was lower in the TS group than in the short abstinence group (mean difference - 9.48, 95%CI - 12.45 to - 6.52, P < 0.001, I2 = 85%). Sensitivity analysis revealed that no single study significantly influenced the results. Employing the GRADE criteria, the initial assessment categorized the overall quality of evidence as low due to the observational nature of the acquired data. All studies were of medium to high quality.

CONCLUSION

This study suggests testicular sperm may be better than ejaculated sperm for improving SDF in infertility cases. Direct comparisons are needed, before deeming short abstinence less effective. Future research should directly compare reproductive outcomes using both methods.

Sperm DNA Fragmentation in Male Infertility: Tests, Mechanisms, Meaning and Sperm Population to Be Tested

Sperm DNA fragmentation (sDF) is a DNA damage able to predict natural conception. Thus, many laboratories added tests for the detection of sDF as an adjunct to routine semen analysis with specific indications. However, some points related to sDF are still open. The available tests are very different each from other, and a direct comparison, in terms of the prediction of reproductive outcomes, is mandatory. The proposed mechanisms responsible for sDF generation have not yielded treatments for men with high levels of sDF that have gained the general consent in clinical practice, thus requiring further research. Another relevant point is the biological meaning to attribute to sDF and, thus, what we can expect from tests detecting sDF for the diagnosis of male infertility. SDF can represent the "tip of iceberg" of a more extended and undetected sperm abnormality somehow impacting upon reproduction. Investigating the nature of such a sperm abnormality might provide novel insights into the link between sDF and reproduction. Finally, several studies reported an impact of native sDF on assisted reproduction technique outcomes. However, to fertilise the oocyte, selected spermatozoa are used where sDF, if present, associates with highly motile spermatozoa, which is the opposite situation to native semen, where most sDF associates with non-viable spermatozoa. Studies comparing the impact of sDF, as assessed in both native and selected spermatozoa, are needed.

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.