BACKGROUND: Sperm DNA fragmentation testing is a valuable tool for predicting male infertility independent of routine semen analysis. However, it remains unclear whether sperm DNA fragmentation affects in vitro fertilization/intracytoplasmic sperm injection outcomes, especially their live birth rates. This study aimed to investigate the effects of sperm DNA fragmentation on the cumulative live birth rates over 1 year of in vitro fertilization/intracytoplasmic sperm injection treatment.
METHODS: This retrospective study included 5050 couples who had undergone in vitro fertilization/intracytoplasmic sperm injection treatment from 2016 to 2022. These patients were divided into four groups according to their sperm DNA fragmentation percentages (group 1: sperm DNA fragmentation ≤10%, group 2: > 10% to ≤20%, group3: > 20% to ≤30%, and group 4: > 30%) determined using the sperm chromatin dispersion assay. Both conservative and optimistic methods were used for estimating cumulative live birth rates, the primary outcome, was defined as an ongoing pregnancy leading to live birth that had arisen from all embryo transfers performed within 1 year following the first ovum pick-up.
RESULTS: The conservative and optimistic cumulative live birth rates showed no significant differences between sperm DNA fragmentation groups when total patients or in vitro fertilization patients were analyzed while adjusting for the confounders. However, compared with those in the group with low sperm DNA fragmentation values (≤10%), the conservative cumulative live birth rate was significantly decreased in intracytoplasmic sperm injection patients in the group with sperm DNA fragmentation > 30%, and the optimistic cumulative live birth rates were significantly decreased in intracytoplasmic sperm injection patients in the three groups with high sperm DNA fragmentation values (> 10% to ≤20%, > 20% to ≤30%, > 30%). These results were further confirmed by the analyses of smooth curves generated by generalized additive models. In intracytoplasmic sperm injection patients, the cumulative live birth rates decreased significantly as the sperm DNA fragmentation increased (p = 0.034), and these effects were stronger with the increase in female age. A similar pattern of correlation between sperm DNA fragmentation and cumulative live birth rate was found in in vitro fertilization patients, but the correlation was not significant (p = 0.232).
CONCLUSIONS: Sperm DNA fragmentation has a significant effect on the cumulative probability of achieving a live birth during 1 year of treatment involving intracytoplasmic sperm injection.

UNASSIGNED: Increased oxidative stress (OS), resulting from the delicate balance between reactive oxygen species (ROS) production and antioxidant defense, is closely linked to sperm abnormalities and male subfertility. Elevated ROS levels particularly affect sperm quality. The vulnerability of spermatozoa to ROS is due to the absence of DNA repair mechanisms and the high presence of polyunsaturated fatty acids in their membranes.
UNASSIGNED: This article updates and advances our understanding of the molecular damage caused by OS in spermatozoa, including lipid peroxidation, DNA damage, motility, and functionality. Additionally, the review discusses the challenges in diagnosing OS in semen and recommends accurate and sensitive testing methods. Case studies are utilized to demonstrate the effective management of male infertility caused by OS.
UNASSIGNED: Highlighting the need to bridge the gap between research and clinical practice, this review suggests strategies for clinicians, such as lifestyle and dietary changes and antioxidant therapies. The review emphasizes lifestyle modifications and personalized care as effective strategies in managing male infertility caused by OS.
UNASSIGNED: This review calls for early detection and intervention and interdisciplinary collaboration to improve patient care in male infertility cases related to increased OS.

OBJECTIVE: 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.
CONCLUSIONS: 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.

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.

OBJECTIVE: Elevated sperm DNA fragmentation has potential implications for semen quality and fertility. The commonly used sperm chromatin dispersion test offers an indirect estimation but has limitations in terms of bias and variability. This study aimed to assess the reliability of the sperm chromatin dispersion assay for predicting assisted reproductive technology outcomes.
METHODS: This systematic review included studies published until December 2023 that adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed/MEDLINE, Scopus, and Google Scholar databases were searched. Various assisted reproductive technology outcomes in patients with high (≥ 30%) versus low (< 30%) sperm DNA fragmentation were compared using a sperm chromatin dispersion assay and including a sub-analysis of intracytoplasmic sperm injection versus in vitro fertilization. A comprehensive meta-analysis software facilitated quantitative analysis with statistical comparisons between cases and controls. Interstudy heterogeneity was assessed, and sensitivity and publication bias tests were performed.
RESULTS: Of the 199 abstracts assessed, 64 full-text articles were screened, and 44 articles were qualitatively synthesized. Fourteen articles representing 5346 participants were quantitatively analyzed. Using the sperm chromatin dispersion assay, elevated sperm DNA fragmentation was associated with lower fertilization and embryo cleavage rates. Notably, high sperm DNA fragmentation levels did not affect the clinical pregnancy, implantation, miscarriage, or live birth outcomes. Sub-analysis revealed lower fertilization, embryo cleavage, clinical pregnancy, live birth rates, and higher miscarriage rates in the intracytoplasmic sperm injection subgroup only.
CONCLUSIONS: The sperm chromatin dispersion assay did not show significant differences in pregnancy or live birth rates between the high- and low-sperm DNA fragmentation groups. Noteworthy, high sperm DNA fragmentation was associated with worse assisted reproductive technology outcomes in the intracytoplasmic sperm injection group. Given the current quality of the evidence, affected by the experimental design and the absence of correction for female factors of infertility, clinicians should be wary of the assay\'s limited predictive power for pregnancy and live birth outcomes.

OBJECTIVE: To study the association between sperm DNA fragmentation index (DFI) and the odds of preeclampsia and other adverse perinatal outcomes after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.
METHODS: A prospective cohort study including infertile couples undergoing conventional IVF or ICSI treatment and their children. Data regarding preeclampsia and perinatal outcomes were derived from the Swedish National Birth Register.
METHODS: 1594 infertile couples undergoing IVF or ICSI treatment and their 1660 children conceived by assisted reproduction.
METHODS: Sperm DNA fragmentation index measured by Sperm Chromatin Structure Assay.
METHODS: The primary outcome was preeclampsia. Secondary outcomes were preterm birth, low birth weight, low Apgar score, and small for gestational age.
RESULTS: With DFI < 20% as a reference, the OR for preeclampsia was statistically significantly increased in the group with DFI ≥ 20% when IVF was used as fertilization method (OR 2.2; 95% CI 1.1 to 4.4; p = 0.02). Already at DFI levels ≥ 10%, in IVF pregnancies, preeclampsia odds were increased in a dose-response manner, from a prevalence of 3.1% in the reference group to more than 10% among those with DFI of 30% or higher. The DFI was not associated with preeclampsia odds in the ICSI group. In the entire cohort, DFI ≥ 20% was associated with an increased OR of preterm birth (OR 1.4; 95% CI 1.0 to 2.0; p = 0.03).
CONCLUSIONS: High DNA fragmentation index was associated with increased odds of preterm birth and, in IVF pregnancies, also increased odds of preeclampsia.

Background/Objectives: Semen cryopreservation is routinely performed in fertility clinics for a variety of reasons, including fertility preservation and storage of donor sperm, yet the freeze-thaw process leads to cellular damage via ice crystal formation, osmotic shock, and supraphysiological levels of oxidative stress. Sperm resistance to damage during the freeze-thaw process varies widely, yet the intrinsic factors associated with sperm cryotolerance are largely unknown. The study aimed to investigate whether poor chromatin condensation renders sperm vulnerable to DNA fragmentation and cell death induced by the freeze-thaw process. Methods: Participants (n = 51) from the general community who met the inclusion criteria collected a semen sample after 3-8 days of abstinence. Neat semen samples underwent traditional semen analysis, aniline blue (AB)-eosin staining for chromatin condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay for DNA fragmentation, and the Annexin V assay for apoptosis/necrosis, prior to being cryopreserved using the liquid nitrogen vapour method and stored at -196 °C. Stored samples were later thawed at room temperature and processed using density gradient centrifugation. Motile sperm concentration, DNA fragmentation and apoptosis/necrosis were analysed in post-thaw samples. Results: As indicated by a significant interaction effect in linear mixed models, an increased proportion of AB-positive sperm in the pre-freeze sample exacerbated the adverse effect of freezing on sperm DNA fragmentation (p = 0.004), late apoptosis (p = 0.007), and necrosis (p = 0.007). AB-staining was positively correlated with all three parameters in the post-thaw sample (all rs ≥ 0.424, all p < 0.01) and remained significant after adjusting for neat sperm concentration (all partial rs ≥ 0.493, all p < 0.01). Similarly, AB-staining was significantly correlated with the percentage point change in sperm DNA fragmentation (rs = 0.366, p = 0.014) and necrosis (rs = 0.403, p = 0.009), both of which remained significant after adjusting for neat sperm concentration (both partial rs ≥ 0.404, both p < 0.01), and borderline significantly correlated with percentage point change in late apoptosis (rs = 0.307, p = 0.051). Conclusions: Sperm with poorly condensed chromatin may be more susceptible to cellular damage during the freeze-thaw process, independent of pre-freeze sperm concentration. These findings may help to explain the intrinsic variation in sperm resistance to cryodamage within and between individuals that is poorly understood.

OBJECTIVE: To investigate the distribution of sperm DNA fragmentation (SDF) values and their association with clinical and seminal parameters in idiopathic infertile men.
METHODS: Data from 3224 primary infertile men (belonging to couples having failed to conceive a pregnancy within 12 months) who underwent a thorough diagnostic work-up were analysed. A SDF value ≥ 30% (according to Sperm Chromatin Structure Assay) was considered pathologic. We excluded: (1) men with genetic abnormalities; (2) men with history of cryptorchidism; (3) men with biochemical hypogonadism; (4) men with clinical varicocele; and (5) men with other possible known aetiological factors. Descriptive statistics and logistic regression analyses were used to describe the whole cohort.
RESULTS: Of all, 792 (23%) men with at least one abnormal WHO semen parameter but without any identified aetiologic factor for infertility, were considered as idiopathic infertile men. Of 792, 418 (52.7%) men had SDF ≥30%. Men with pathologic SDF were older (p = .02), had higher Follicle-stimulating hormone (FSH) (p = .04) but lower total testosterone (p = .03) values than those with SDF <30%. The homoeostatic model assessment index for insulin resistance (HOMA-IR) was higher in men with SDF ≥30% (p = .01). Idiopathic infertile men with SDF ≥30% presented with lower sperm concentration (p < .001) and lower progressive sperm motility (p < .01) than those with SDF < 30%. Logistic regression analysis revealed that older age (OR: 1.1, p = .02) and higher HOMA-IR score (OR: 1.8, p = .03) were associated with SDF ≥ 30%, after accounting for FSH and sperm concentration values.
CONCLUSIONS: Approximately half of infertile men categorized as idiopathic had pathologic SDF values. Idiopathic infertile men with pathologic SDF showed worse clinical, hormonal and semen parameters than those with normal SDF values. These results suggest that including SDF testing could be clinically relevant over the real-life management work-up of infertile men.

OBJECTIVE: Are the prospective reproductive outcomes in couples experiencing recurrent pregnancy loss (RPL) related to the sperm DNA fragmentation index (DFI), as measured by sperm chromatin structure assay, sperm morphology and sperm concentration at referral?
METHODS: This prospective cohort study included 95 couples seen between 1 April 2018 and 1 December 2019 at the tertiary Copenhagen RPL Unit, Copenhagen University Hospital, Rigshospitalet and Hvidovre Hospital, Denmark. The couples had experienced three or more unexplained consecutive pregnancy losses or two late pregnancy losses (>12 weeks gestation). Follow-up was 12-31 months.
RESULTS: Eighty-one of 95 (85.3%) couples achieved pregnancy after referral. In the first pregnancy after referral, 46 (56.8%) couples achieved a live birth, and 35 (43.2%) couples experienced another pregnancy loss. There was no significant difference in baseline DFI between couples that experienced pregnancy loss [median 11.7, interquartile range (IQR) 9.1-17.3] and couples that achieved a live birth (median 12.5, IQR 9.3-16.5; P = 0.971). Improving sperm morphology increased the odds of a live birth after referral (adjusted OR 1.26, 95% CI 1.05-1.52; P = 0.014). DFI and sperm concentration were not associated with the outcome of the first pregnancy after referral. Overall, 35.9% of the men had DFI ≥15 at inclusion. Couples that failed to achieve pregnancy had a higher median DFI of 17.7 (IQR 7.7-27.2) compared with the rest of the cohort (median 12.0, IQR 9.3-16.5; P = 0.041).
CONCLUSIONS: At referral, sperm DFI, morphology and concentration cannot be used to identify RPL couples at risk of another pregnancy loss. Increased baseline DFI was associated with difficulty achieving another pregnancy, and improving sperm morphology was associated with increased odds of a live birth.

BACKGROUND: Through the ages, infertility, affecting 8% to 12% of couples worldwide, has been a perturbing clinical problem. Approximately 40% to 50% of all infertility cases are due to \'male factor\' infertility. Semen analysis is crucial in routinely evaluating idiopathic male infertility. Studies support the idea that semen parameters are associated with serum lipids and sperm DNA fragmentation (SDF). Therefore, it is possible to evaluate male infertility by serum lipid levels, especially before assisted reproduction technology, and modify it by bringing about lifestyle modifications. This study aimed to measure the correlation of SDF with levels of total cholesterol (TC), triglycerides (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) among males with abnormal semen parameters.
METHODS: A cross-sectional analytical study was conducted in the infertility clinic of a tertiary care hospital. A total of 106 infertile males with abnormal semen analysis as per the WHO criteria (2010) were enrolled in the study. After routine semen analysis, SDF was studied using the comet assay. The serum fasting lipid profile was analyzed using the spectrophotometric kit in the autoanalyzer. The relationship of SDF with serum lipid profile parameters was analyzed.
RESULTS: Out of 106 infertile men, 52% (n = 55) had severe SDF. A modest positive correlation was observed between SDF (percentage of DNA in comet tail) and serum lipid values (serum TG, serum LDL, and serum VLDL).
CONCLUSIONS: Our study is novel in its research on the correlation between SDF and serum lipid values. Based on the findings of our study, it can be concluded that a significant level of SDF was observed in men with high levels of serum TG, LDL, and VLDL. This provokes a potential relationship between sperm DNA integrity and serum lipid profile, which warrants further research.