Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Several cellular insults can result in sperm DNA fragmentation either on one or both DNA strands. Oxidative damage, premature interruption of the apoptotic process and defects in DNA compaction during spermatogenesis are the main mechanisms that cause DNA breaks in sperm. The two-tailed Comet assay is the only technique that can differentiate single- (SSBs) from double- (DSBs) strand DNA breaks. Increased levels of the phosphorylated isoform of the H2AX histone are directly correlated with DSBs and proposed as a molecular biomarker of DSBs. We have carried out a narrative review on the etiologies associated with SSBs and DSBs in sperm DNA, their association with reproductive outcomes and the mechanisms involved in their repair. Evidence suggests a stronger negative impact of DSBs on reproductive outcomes (fertilization, implantation, miscarriage, pregnancy, and live birth rates) than SSBs, which can be partially overcome by using intracytoplasmic sperm injection (ICSI). In sperm, SSBs are irreversible, whereas DSBs can be repaired by homologous recombination, non-homologous end joining (NHEJ) and alternative NHEJ pathways. Although few studies have been published, further research is warranted to provide a better understanding of the differential effects of sperm SSBs and DSBs on reproductive outcomes as well as the prognostic relevance of DNA breaks discrimination in clinical practice.

Infertility is defined as the inability to conceive after 12 months of regular, unprotected intercourse (Sabanegh & Agarwal, 2010). Although 60%-75% of couples conceive within 6 months, and 90% within 12 months (Spira, 1986), approximately 48.5 million couples worldwide are considered infertile within this definition (Agarwal et al., 2019; Sharlip et al., 2002). Male factor infertility affects up to 50% of couple infertility and is solely responsible for 20% of overall infertility (Thonneau et al., 1991). In recent decades, the incidence of male factor infertility has increased (Turner et al., 2020; Zandieh et al., 2018). Semen analysis is considered as the cornerstone of the male fertility evaluation. This analysis provides information into the possible extent and severity of infertility problems, and aids in diagnosis and clinical management. Based on several population studies, the World Health Organization (WHO) provided updated sampling and laboratory guidelines with clinical thresholds to evaluate male reproductive potential through semen analysis (Mayorga-Torres, Camargo, Cadavid, du Plessis, & Cardona Maya, 2017). However, there remain several limitations associated with the conventional semen analysis in the assessment of male infertility (Majzoub, Agarwal, & Esteves, 2019). These limitations have led to the development of advanced sperm function and seminal fluid quality assessments, such as oxidative stress and sperm DNA fragmentation (SDF), that may better guide diagnostics, management and the prediction of male fertility outcomes (Esteves, Sharma, Gosálvez, & Agarwal, 2014). Spermatozoa are highly differentiated cells, which are made up of a head, mid piece and tail. The head of the spermatozoa contains the haploid genome that is transmitted into the oocyte after successful fertilization. The integrity and composition of the sperm DNA is different from that of somatic cells and critical for its fusion with the maternal genome (Conwell, Vilfan, & Hud, 2003). Adequate sperm DNA integrity is critical for successful fertilization, embryo development, implantation and establishment of pregnancy as it contributes towards 50% of the embryonic genome (Baskaran et al., 2019; Braude, Bolton, & Moore, 1988). Sperm DNA integrity is therefore considered as an important marker of fertility potential of spermatozoa (Cho & Agarwal, 2018).

Purpose The use of antioxidants is common practice in the management of infertile patients. However, there are no established guidelines by professional societies on antioxidant use for male infertility. Materials and Methods Using an online survey, this study aimed to evaluate the practice pattern of reproductive specialists to determine the clinical utility of oxidative stress (OS) testing and antioxidant prescriptions to treat male infertility. Results Responses from 1,327 participants representing 6 continents, showed the largest participant representation being from Asia (46.8%). The majority of participants were attending physicians (59.6%), with 61.3% having more than 10 years of experience in the field of male infertility. Approximately two-thirds of clinicians (65.7%) participated in this survey did not order any diagnostic tests for OS. Sperm DNA fragmentation was the most common infertility test beyond a semen analysis that was prescribed to study oxidative stress-related dysfunctions (53.4%). OS was mainly tested in the presence of lifestyle risk factors (24.6%) or sperm abnormalities (16.3%). Interestingly, antioxidants were prescribed by 85.6% of clinicians, for a duration of 3 (43.7%) or 3–6 months (38.6%). A large variety of antioxidants and dietary supplements were prescribed, and scientific evidence were mostly considered to be modest to support their clinical use. Results were not influenced by the physician's age, geographic origin, experience or training in male infertility. Conclusions This study is the largest online survey performed to date on this topic and demonstrates 1) a worldwide understanding of the importance of this therapeutic option, and 2) a widely prevalent use of antioxidants to treat male infertility. Finally, the necessity of evidence-based clinical practice guidelines from professional societies is highlighted.

The advent of intracytoplasmic sperm injection (ICSI) has changed the human reproduction landscape by overcoming several limitations related to both male and female infertility factors. However, despite the development of new technologies, the live-birth rate with ICSI has not exceeded 30%. In order to improve assisted reproductive technology outcomes, advanced sperm function analysis have gained increased attention and the effects of sperm DNA fragmentation (SDF) on assisted reproduction success are being extensively studied. Utilizing ejaculated sperm with an elevated SDF has been found to result in poor ICSI outcomes. Furthermore, studies have reported that testicular sperm has lower SDF level, when compared to ejaculated sperm. This has led a number of clinicians world-wide to offer testicular sperm retrieval for ICSI in non-azoospermic males with high SDF. This practice has remained controversial due to lack of high quality evidence.

Sperm DNA fragmentation (SDF) is implicated in male infertility and adverse reproductive outcomes. With the publication of many studies regarding the etiologies and contributors to SDF, as well as the effects of SDF, guidelines are necessary to aid clinicians in the application of SDF for male fertility evaluation. Two recent clinical practice guidelines were published by Agarwal et al and Esteves et al. In this article, we have evaluated and compared both guidelines. We have found fairly similar recommendations between the two guidelines and have also highlighted the differences between them. Finally, we have summarized and combined the best practice recommendations from both guidelines.

The current WHO 2010 manual for human semen analysis defines leukocytospermia as the presence of peroxidase-positive leukocytes at a concentration >1×10 6 /mL of semen. Granular leukocytes when activated are capable of generating high levels of reactive oxygen species in semen resulting in oxidative stress. Oxidative stress has been correlated with poor sperm quality, increased level of sperm DNA fragmentation and low fertility potential. The presence of leukocytes and pathogens in the semen may be a sign of infection and/or localized inflammatory response in the male genital tract and the accessory glands. Common uro-pathogens including Chlamydia trachomatis , Ureaplasma urealyticum , Neisseria gonorrhoeae , Mycoplasma hominis , and Escherichia coli can cause epididymitis, epididymo-orchitis, or prostatitis. The relationship between leukocytospermia and infection is unclear. Therefore, we describe the pathogens responsible for male genital tract infections and their association with leukocytospermia. The review also examines the diagnostic tests available to identify seminal leukocytes. The role of leukocytospermia in male infertility and its management is also discussed.

HIV-1 from infected subjects has been characterized in order to provide a more accurate view of the strains that are currently found in a given region. In this report, we focused on characterizing the pol gene diversity obtained from newly diagnosed patients in Santos metropolitan area, Brazil. This region is composed of nine cities and an international port. Analysis of the 33 samples revealed that 22 strains belonged to subtype B, 4 to subtype F, and 2 to subtype C; 5 strains were B/F recombinants. Our results demonstrated that 18.2% of samples were primary antiretroviral resistance genotypic mutations, with high-level resistance to reverse transcriptase inhibitors in both subtypes B and F and in recombinant forms B/F. Our data revealed that the primary antiretroviral resistance genotypic mutations should be carefully investigated in developing countries with widespread access to antiretrovirals, such as Brazil.