Sperm DNA fragmentation valued by SCSA and its correlation with conventional sperm parameters in male partner of recurrent spontaneous abortion couple

The objective of this study is to evaluate the predictive value of sperm DNA fragmentation Index (DFI) in unexplained recurrent spontaneous abortion (RSA) and to investigate its correlation with conventional sperm parameters. Besides, we aimed to reveal the necessity of establishing a DFI clinical threshold of each laboratory for the prognostic diagnosis of RSA and establish our own DFI threshold. Semen samples were collected from male partners of RSA patients (n = 139) and healthy recent fathers (control, n = 200). DFI was tested using SCSA and conventional semen analysis was performed using an automatic semen analyzer. The DFI value and distribution were compared between the two groups using corresponding statistical software. The diagnostic threshold value was established by ROC curve. The correlation between DFI and the conventional semen parameters of the 139 cases was further analyzed using Student's t test and Mann-Whitney U test. Our result showed that DFI was significantly higher in RSA patients compared with normal donor controls. We established our own DFI threshold at 13.59%. There was only a weak partial correlation between DFI values and conventional sperm analysis parameters. Our present study suggested that DFI might be used as a valuable predictor for RSA independent of conventional sperm parameters. Additionally, we recommend that each laboratory should establish its own clinical DFI threshold for more precise prediction of RSA and we recommend that sperm DNA fragmentation test should be included in complete sperm quality assessment in addition to conventional semen analysis for RSA male partners.

Cryopiece, a novel carrier with faster cooling rate, high recovery rate and retrieval rate, for individual sperm cryopreservation

Background

Cryopreservation of extremely few spermatozoa is still a major challenge for male fertility preservation. This study aims to evaluate the cooling rate, recovery rate, and retrieval rate, along with other parameters of spermatozoa that cryopreserved using Cryopiece, a novel carrier, for individual sperm cryopreservation.

Methods

Semen samples from 60 fertile donors were collected, and each semen sample was screened for motile sperm and mixed with cryoprotective agent (CPA), and then frozen using Cryopiece, micro-straw, and mini-straws. The cooling rate, retrieval rate, and recovery rate, morphology, DNA fragmentation index (DFI) and mitochondrial membrane potential (MMP), were compared among the un-frozen sperm and the sperm cryopreserved using these carriers.

Results

Cryopiece possessed the fastest cooling rate. After freeze-thaw, the average retrieval rate of sperm cryopreserved using Cryopiece was 96.25%, and the average recovery rate was 64.40%, which were higher than that of sperm cryopreserved using the other two carriers (71.42% and 54.30% for micro-straw, and 63.54% and 58.04% for mini-straw, respectively). There was no significant impact on DFI after sperm cryopreservation, and no significant difference in morphology between sperm cryopreserved using these carriers was observed. Though MMP of sperm changed significantly after cryopreservation, micro-straw maintained sperm MMP better than Cryopiece and mini-straw did, while no significant difference was observed in MMP between sperm cryopreserved using Cryopiece and mini-straw.

Conclusions

Cryopiece produced satisfying retrieval and recovery rates in sperm cryopreservation and should be an ideal carrier for cryopreservation of small number of sperm.

Does sperm DNA fragmentation affect clinical outcomes during vitrified-warmed single-blastocyst transfer cycles? A retrospective analysis of 2034 vitrified-warmed single-blastocyst transfer cycles

BACKGROUND

Sperm DNA is essential in embryo development. The sperm DNA fragmentation index (DFI), which reflects the degree of sperm DNA fragmentation (SDF), is a crucial biomarker in evaluating the sperm quality. However, whether SDF influences the clinical outcomes after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) remains controversial.

OBJECTIVE

This study aimed to investigate the relationship between sperm DNA SDF and clinical outcomes of vitrified-warmed single-blastocyst transfer cycles.

MATERIALS AND METHODS

A total of 2034 vitrified-warmed single-blastocyst transfer cycles (536 from ICSI and 1498 from IVF) were included in this analysis. According to the sperm DFI, all cycles were divided into two groups (DFI < 27.3% group and DFI ≥ 27.3% group). The Mann-Whitney and chi-squared tests were used to compare patient characteristics and clinical outcomes between the two groups. Furthermore, logistic regression analysis was performed to analyze the association between SDF and clinical outcomes.

RESULTS

The chi-squared test showed no differences in positive human chorionic gonadotropin (HCG) rate, clinical pregnancy rate, miscarriage rates, and live birth rate between the two groups. Logistic regression analysis indicated that SDF was not a prognostic predictor of positive HCG, clinical pregnancy, miscarriage, and live birth.

CONCLUSION

SDF was not associated with clinical outcomes either in ICSI or IVF cycles during vitrified-warmed single-blastocyst transfer cycles.

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.

Improved sperm DNA fragmentation levels in infertile men following very short abstinence of 3-4 hours

Background

Limited data exists on possible approaches to improve sperm DNA fragmentation index (DFI) when no identifiable cause is found. The effect of short abstinence on sperm parameters has been extensively studied, but rarely reported on the effect on DFI in infertile men. In this study, we aimed to determine whether a second ejaculate provided after very short abstinence demonstrates lower DFI rates in infertile men.

Methods

This prospective cohort study was conducted at Mount Sinai Hospital, Toronto, Canada, a tertiary university affiliated hospital. All men having DFI testing in addition to the standard semen analysis were identified via a prospectively collected database. Infertile men were instructed to provide two semen samples 3-4 hours apart (the first sample was given after 2-5 days of abstinence) to test the effect on DFI levels. Data analysis was performed for the comparison of the change in sperm parameters and DFI between samples and between men with DFI above and under 30%.

Results

A total of 52 men provided double ejaculates 3-4 hours apart. In the entire group, DFI decreased from 38.9%±21.4% to 35.1%±21.6% in the second sample (P<0.001). Semen volume was lower on the second sample (2.3±1.4 vs. 1.5±0.9 mL, P<0.001), while the remaining parameters did not change. Forty out of 52 patients (76.9%) had improved DFI (average of 6.0±4.0 percentage points). Change in DFI varied with 22/52 (42.3%) and 7/52 (13.5%) of patients found to have decreases in DFI >5% and >10% in the second ejaculate, respectively. For men with DFI of 30-40%, 64% (7/11) of DFIs reduced to the under 30% range. First DFI value was the only parameter associated with DFI decrease to under 30% in multivariate models [odds ratio (OR), 0.62; 95% confidence interval (CI): 0.39-0.98; P=0.04].

Conclusions

This study identified significant improvements in DFI in infertile men providing a second sample after 3-4 hours. Controlled trials are needed to determine if reproductive outcomes are improved using a second ejaculate for infertile men with high initial sperm DFI values.

What sperm parameters effect blastocyst formation and quality during ICSI with severe male infertility

Sperm-derived genetic material contributes half of the genome to the embryo, hence it's crucial to investigate which sperm parameter influences blastocyst formation in the intracytoplasmic sperm injection (ICSI) cycles with severe male infertility. The retrospective study analyzed 296 ICSI cycles with severe oligoasthenoteratozoospermia (OAT) and 99 ICSI cycles with preimplantation genetic testing for aneuploidy (PGT-A). Following the correlation analysis, data stratifications were performed in the OAT ICSI subgroup. The results showed that the matching blastocyst in the OAT ICSI cycles had inferior sperm parameters. DFI and sperm morphology had an influence on the blastocyst formation rate and the high-quality blastocysts formation rate on Day6, but no significant effect on the blastocyst development on Day 5. The high-quality blastocysts formation rate and ratio of high-quality blastocyst on Day 6 were demonstrably better in the subgroup of the teratozoospermic morphology when DFI was within the normal range. In the case of the normal sperm morphology, no statistically significant difference was found in blastocyst development, although there were numerical differences within different DFI subgroups. It was concluded that the blastocyst quality and development declined with the decreased sperm qualities.

Shugan Tongluo Qiangjing recipe protects against varicocele of EVC rats through modulating sperm DNA damage, telomere expression and oxidative stress

Varicocele (VC) refers to expansion and tortuosity of spreading venous plexus in spermatic cord due to poor blood flow. This study aimed to investigate effects of Shugan Tongluo Qiangjing recipe (SGTL) on sperm DNA damage and oxidative stress in experimental VC (EVC) rats. EVC model was established by partial ligation of left renal vein. Spermatic vein diameter, testicular weight, sperm DNA fragmentation index (DFI) were evaluated. Telomere reverse transcriptase (TERT) expression, telomere gene transcription, and testicular tissue morphology were determined·H2O2, catalase, SOD, T-AOC were measured with colorimetry. SGTL significantly decreased spermatic vein diameter (P=0.000) and increased testicular weight (P=0.013) of rats compared those of EVC rats. SGTL maintained testicular tissue morphology in EVC rats. SGTL markedly reduced sperm DFI value in sperm of rats compared to EVC rats (P=0.000). SGTL significantly enhanced TERT expression and telomere gene transcription (P=0.028) in testis of rats compared to EVC rats. SGTL reduced H2O2 levels (P=0.001) and promoted CAT activity (P=0.016), SOD activity (P=0.049), and T-AOC activity (P=0.047) of rats, compared to EVC rats. In conclusion, SGTL could reduce pathogenic process of EVC by reducing sperm DNA damage and regulating telomere length in EVC rats, which may be related to oxidative stress regulation.

Impact of sperm DNA fragmentation in couples with unexplained recurrent pregnancy loss: A cross-sectional study

OBJECTIVE

Recurrent pregnancy loss (RPL) has a multifactorial etiology, with a majority of cases remaining unexplained. To account for these unexplained cases, possible male factors are being explored. Conventional semen analysis lacks a qualitative assessment of sperms and information regarding sperm DNA integrity. Sperm DNA fragmentation (SDF) has diagnostic value in unexplained RPL, and it may account for a number of unexplained cases. Hence, we planned a study to explore and evaluate the impact of sperm DNA fragmentation in couples with unexplained recurrent pregnancy losses.

STUDY DESIGN

Analytical cross-sectional study was conducted at a tertiary-level referral facility in India between August 2021 and July 2023. Participants (n = 70) were divided into two groups-male partners of couples with unexplained RPL (following spontaneous conceptions) (n = 35) and men with at least one previous live birth (spontaneous or following fertility treatments for female factor infertility such as ovulation induction or intrauterine insemination) as controls (n = 35). Neither of the two groups of couples recruited for this study had undergone ART as fertility treatment. Primary outcome assessed was mean DNA fragmentation index (DFI). Secondary outcomes included differences in semen parameters such as sperm concentration, progressive sperm motility and morphology, proportion of men with high (≥30%) and low DFI in the two groups, and the association between various semen parameters and DFI.

RESULTS

Univariate logistic regression revealed that sperm DNA fragmentation was higher in men with unexplained RPL (30.0; IQR (interquartile range) 19.0, 46.0) as compared to controls (22.0; IQR 14.0, 30.0) although it was not statistically significant (OR, odds ratio, 1.02; 95% CI 1.0-1.1, p = 0.08). A higher proportion of men with unexplained RPL had DFI ≥30% compared to controls (54.2% vs. 25.7%; OR 3.43 (95% CI 1.2-9.4); p = 0.02). No statistically significant differences were observed in semen volume, sperm concentration, progressive motility, and morphology between the two groups. Sperm DNA fragmentation index also showed a weak but significant inverse relationship with sperm morphology (r = -0.336, p = 0.004).

CONCLUSION

The current study did not show any significant difference in the mean sperm DNA fragmentation levels in male partners of couples with unexplained RPL compared to controls. However, a higher proportion of men with DFI ≥30% were observed in unexplained RPL population when compared to controls.