Effect of sperm DNA fragmentation on blastocyst formation rate and subsequent IVF outcome

Background: Male infertility associated with sperm DNA alteration has raised a new issue in assisted reproduction techniques (ARTs).Methods: It was a retrospective analytical study on 250 cases of routine IVF/ICSI performed at Swagat ART Centre from January 2017 to January 2020. We divided the patient according to the sperm DNA fragmentation index (DFI) as normal DFI≤15%, n=95, a moderate DFI≤30%, n=89, and a high DFI group >30%, n=66. Oocytes of each patient were almost equally divided and fertilization method was adopted as half IVF half ICSI or only ICSI in poor quality (oligo, astheno, teratozoospermia or with two or all three defect and compared the fertilization, cleavage, embryo formation, blastocyst formation, pregnancy and early embryo formation rate among these six groups. Results: Fertilization, cleavage, embryo formation, and clinical pregnancy rates were reported as higher in ≤15% DFI group of both IVF and ICSI-ET (87.3±26.2, 77.7±26.1, 68.2±28.8, 50.8 in IVF and 78.3±17.8, 70.3±31.2, 67.2±28.8, 57.6 respectively). Significant differences (p<0.01) are observed among all six groups. Higher abortion rate is observed in high DFI group of both IVF and ICSI.Conclusions: High sperm DFI causes low blastocyst formation and pregnancy outcome. Higher abortion rate observed in high DFI group indicated need of further study.

Impact of environmental factors on human semen quality and male fertility: a narrative review

Background Worldwide rising trend in infertility has been observed in the past few years with male infertility arising as a major problem. One main reason for the rise in male infertility cases is declining semen quality. It was found that any factor that affects semen quality can affect male fertility. There are several modifiable factors affecting semen quality including air pollution, use of pesticides and harmful chemicals, exposure to excessive heat, and can lead to decreased male fertility. Main body The present review focuses on some of these environmental factors that affect semen quality and hence, can cause male infertility. The literature from 2000 till June 2021 was searched from various English peer-reviewed journals and WHO fact sheets using the USA National Library of Medicine (PubMed) database, the regional portal of Virtual Health Library, and Scientific Electronic Library Online. The search terms used were: “Air pollution and male fertility”, “Chemicals and male infertility”, “Heat exposure and infertility”, “heavy metals and male fertility”. Conclusion Adverse environmental factors have a significant impact on semen quality, leading to decreased sperm concentration, total sperm count, motility, viability, and increased abnormal sperm morphology, sperm DNA fragmentation, ultimately causing male infertility. However, all these factors are modifiable and reversible, and hence, by mere changing of lifestyle, many of these risk factors can be avoided.

Relationship Among Traditional Semen Parameters, Sperm DNA Fragmentation, and Unexplained Recurrent Miscarriage: A Systematic Review and Meta-Analysis

Several studies have explored the relationship among traditional semen parameters, sperm DNA fragmentation (SDF), and unexplained recurrent miscarriage (RM); however, the findings remain controversial. Hence, we conducted a meta-analysis to explore the relationship among traditional semen parameters, SDF, and unexplained RM. Multiple databases, including PubMed, Google Scholar, MEDLINE, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure (CNKI), were searched to identify relevant publications. From the eligible publications, data were extracted independently by two researchers. A total of 280 publications were identified using the search strategy. According to the inclusion/exclusion criteria, 19 publications were eligible. A total of 1182 couples with unexplained RM and 1231 couples without RM were included in this meta-analysis to assess the relationship among traditional semen parameters, SDF, and unexplained RM. Our results showed that couples with unexplained RM had significantly increased levels of SDF and significantly decreased levels of total motility and progressive motility compared with couples without RM, although significant differences were not observed in the semen volume, sperm concentration, and total sperm count between couples with and without RM. The SDF assay may be considered for inclusion in evaluations of couples with unexplained RM.

Impacts of COVID-19 and SARS-CoV-2 on male reproductive function: a systematic review and meta-analysis protocol

IntroductionCOVID-19 pandemic caused by SARS-CoV-2 has become a global health challenge. SARS-CoV-2 can infect host cells via the ACE2 receptor, which is widely expressed in the corpus cavernosum, testis and male reproductive tract, and participates in erection, spermatogenesis and androgen metabolism. Also, the immune response and persistent fever resulting from COVID-19 may lead to damage of the testicular activity, consequently compromising male fertility.Methods and analysisPubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure, China Science and Technology Journal database, Chinese Biomedical Databases and Wanfang Data will be systematically searched for observational studies (case–control and cohort) published up to March 2021 in English or in Chinese literature on the impacts of COVID-19 and SARS-CoV-2 on male reproductive function. This protocol will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines and Meta-analysis of Observational Studies in Epidemiology. The primary outcome will be semen parameters, and the additional outcomes will include: (a) detection of SARS-COV-2 in semen, (b) male sexual hormones, (c) sperm DNA fragmentation index, (d) erectile function, (e) evaluation of testis and also the male genital tract. Two reviewers will independently extract data from the included studies based on a predesigned data extraction form. The risk of bias of included studies will be evaluated through the Newcastle-Ottawa Scale for observational studies. Review Manager software V.5.3 will be used for statistical analysis. Q statistic and I² test will be performed to assess the heterogeneity among studies. Sensitivity analysis will be used to explore the robustness of pooled effects. We will use the Grading of Recommendations Assessment, Development and Evaluation system to assess the quality of evidence.Ethics and disseminationEthical approval is not required and results will be published in a peer-reviewed journal.PROSPERO registration numberCRD42021245161.

The Sixth Edition of the WHO Manual for Human Semen Analysis: A Critical Review and SWOT Analysis

Semen analysis is the cornerstone of male fertility evaluation with WHO guidelines providing the basis for procedural standardization and reference values worldwide. The first WHO manual was published in 1980, and five editions have been subsequently released over the last four decades. The 6th Edition was published in July 2021. In this review, we identify the key changes of this 6th Edition. Additionally, we evaluate the utility of this 6th Edition in clinical practice using SWOT (strengths, weaknesses, opportunities, and threats) analysis. This new Edition has made the analysis of basic semen parameters more robust, taking into account the criticisms and grey areas of the previous editions. The tests assessing sperm DNA fragmentation and seminal oxidative stress are well-described. The main novelty is that this latest edition abandons the notion of reference thresholds, suggesting instead to replace them with “decision limits”. While this seems attractive, no decision limits are proposed for either basic semen parameters, or for extended or advanced parameters. This critical review of the 6th Edition of the WHO laboratory manual combined with a SWOT analysis summarizes the changes and novelties present in this new Edition and provides an in-depth analysis that could help its global use in the coming years.