New Insights beyond Established Norms: A Scoping Review of Genetic Testing for Infertile Men.

Purpose : From a diagnostic standpoint, certain approaches to genetic screening in clinical practice remain ambiguous in the era of assisted reproduction. Even the most current guidelines do not provide definite guidance on testing protocols, leaving clinicians to carefully determine which tests best serve patients struggling with infertility. The lack of uniformity in the current practice of male fertility evaluation can prove to be quite costly, thus necessitating healthcare practitioners to carefully appraise the necessity and weigh the advantages against potential economic and psychological detriments. The objective of this review is to map the existing literature on the general topic of the clinical indications of routine karyotyping and/or AZF screening in infertile men, identify key concepts, determine where the gaps are, and lastly, provide an overview of the conclusions drawn from a body of knowledge that varies widely in terms of methodologies or disciplines. Materials and Methods : A thorough search was conducted for the published findings up until July 2023, utilizing PubMed (MEDLINE). This comprehensive search involved the use of specific search keywords, either individually or in combination. The search terms employed were as follows: "Karyotype", "Klinefelter" or "KS" or "47,XXY", "AZF" or "Azoospermi*" and/or "microdeletion*" in the title or abstract. Once the titles and abstracts of selected articles were obtained, the complete texts of linked papers were meticulously scrutinized. Results : A total of 191 records were identified from PubMed. During screening, 161 records (84.3%) were eliminated. Finally, 30 papers were included in this scoping review, which was conducted in 18 countries. The number of sequence tag sites (STSs) used in the studies varied from 5 to 59. The rate of AZF deletions among patients with NOA ranged from 1.3% to 53%. The mean frequency was estimated to be 5.6%. The rate of YCM among patients with XXY karyotype was nil in 19 out of 30 studies (63%), whilst, in the remaining studies, the rate varied from 0.8% to 67%. Conclusion : This review provides insights into managing male infertility. The presence of spermatozoa in ejaculation and successful surgical retrieval cannot be excluded for individuals with AZFb/AZFbc microdeletions. Screening for Y chromosome microdeletions is not needed for mosaic or classic KS. Only 1% of individuals with sperm concentration exceeding 1×106 sperm/mL and less than 5×106 sperm/mL exhibit AZF microdeletions; therefore, testing referral for such populations may need reassessment. Individuals with mosaic monosomy X karyotype and certain chromosomal anomalies should be referred for AZF deletion screening. These findings have implications for male infertility management and future research. .

Assessment of artificial intelligence model and manual morphokinetic annotation system as embryo grading methods for successful live birth prediction: a retrospective monocentric study.

PURPOSE: The introduction of the time-lapse monitoring system (TMS) and the development of predictive algorithms could contribute to the optimal embryos selection for transfer. Therefore, the present study aims at investigating the efficiency of KIDScore and iDAScore systems for blastocyst stage embryos in predicting live birth events. METHODS: The present retrospective study was conducted in a private IVF Unit setting throughout a 10-month period from October 2021 to July 2022, and included the analysis of 429 embryos deriving from 91 IVF/ICSI cycles conducted due to infertility of various etiologies. Embryos incubated at the Embryoscope+ timelapse incubator were analyzed through the established scoring systems: KIDScore and iDAScore®. The main outcome measure was the comparison of the two scoring systems in terms of live birth prediction. Embryos with the higher scores at day 5 (KID5 score/iDA5 score) were transferred or cryopreserved for later use. RESULTS: Embryos with high KID5 and iDA5 scores positively correlated with the probability of successful live birth, with KID5 score yielding a higher efficiency in predicting a successful reproductive outcome compared to a proportionally high iDA5 score. KID5 demonstrated conservative performance in successfully predicting live birth compared to iDA5 score, indicating that an efficient prediction can be either provided by a relatively lower KID5 score or a relatively higher iDA5 score. CONCLUSION: The developed artificial intelligence tools should be implemented in clinical practice in conjunction with the conventional morphological assessment for the conduction of optimized embryo transfer in terms of a successful live birth.

Technical Aspects and Clinical Limitations of Sperm DNA Fragmentation Testing in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations.

PURPOSE: Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. MATERIALS AND METHODS: Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. RESULTS: The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). CONCLUSIONS: This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial.

How to select healthy sperm for intracytoplasmic sperm injection in samples with high sperm DNA fragmentation?

The body of evidence supports the negative impact of increased sperm DNA fragmentation (SDF) on natural fertility as well as assisted reproduction conditions. High SDF has been correlated with low pregnancy and delivery rates following intrauterine insemination. Also, high SDF is accused of reducing the rates of fertilization, implantation, pregnancy, and live birth following in-vitro fertilization (IVF). Despite no impact of high SDF on fertilization or pregnancy rates following intracytoplasmic sperm injection (ICSI), it has been correlated with poor embryo quality and a higher risk of miscarriage. Several methods have been introduced to help select sperm with the best DNA quality to be used in assisted reproductive technology procedures. These include magnetic-activated cell sorting, intracytoplasmic morphologically selected sperm injection, physiologic ICSI, and microfluidic sperm sorters, among others. This article aimed to discuss the impact of high SDF in infertile men on the reproductive outcome of couples undergoing IVF/ICSI. Additionally, this review highlights the principles, advantages, and limitations of different techniques that are currently used for the selection of sperm with intact DNA to be utilized for ICSI.

Sperm DNA fragmentation test: usefulness in assessing male fertility and assisted reproductive technology outcomes.

Male infertility is attributed to multiple factors including high levels of sperm DNA fragmentation (SDF). Conventional semen analysis continues to be the gold standard for diagnosis of male factor infertility around the world. However, the limitations of basic semen analysis have prompted the search for complementary assessments of sperm function and integrity. Sperm DNA fragmentation assays (direct or indirect) are emerging as important diagnostic tools in male infertility workups, and have been advocated for use in infertile couples for a variety of reasons. While a controlled degree of DNA nicking is required for appropriate DNA compaction, excessive fragmentation of sperm DNA is linked to impaired male fertility potential, decreased fertilization, poor embryo quality, recurrent pregnancy loss, and failure of assisted reproductive technology procedures. However, there is an ongoing debate regarding whether or not to employ SDF as a routine test for male infertility. This review compiles up-to-date information regarding the pathophysiology of SDF, the currently available SDF tests, and the role of SDF tests in natural and assisted conception conditions.

Time-lapse embryo monitoring: does it add to standard in-vitro fertilization/intra cytoplasmic sperm injection?

Since the first pioneering studies on time-lapse systems (TLSs) for embryo incubation, many things have changed. Two main factors influence the development of modern time-lapse incubators for human in-vitro fertilization (IVF): 1) the switch from traditional cell culture incubators to benchtops incubators, more suitable for human IVF; and 2) the improvement of imaging technology. Another major factor for the increase in the utilization of TLSs in IVF labs over the last decade was the advances in computer/wireless and smartphone/tablet technology, which allowed patients to see the footage of their growing embryos. Hence, more user-friendly features have allowed their introduction and routine use in IVF labs while image-capturing software has enabled storage and providing additional information to the patients concerning the development of their embryos. This review aims to describe the history and the different TLSs available in the market, to summarize the research and clinical results obtained by using this technology, and to reflect on how this technology is changing the modern IVF laboratory. The current limitations of TLSs will be also reviewed.

Oocytes evaluation and in-vitro fertilization/intra cytoplasmic sperm injection outcomes.

The identification of markers capable of evaluating oocyte quality, its maturation, function, and embryo progression and implantation potential has frequently initiated research interest. However, to date, univocal criteria of oocyte competence do not exist. A major cause of low oocyte quality is evidently advanced maternal age. However, other factors may influence oocyte competence. Among these are obesity, lifestyle factors, genetic and systematic pathologies, ovarian stimulation protocols, laboratory procedures, culture, and environmental conditions. The morphological and maturational evaluation of oocytes is probably the most widely used. Several morphological features, both cytoplasmic (cytoplasmic pattern and hue, presence of vacuoles, refractile bodies, granulation, and smooth endoplasmic reticulum clusters) and extra-cytoplasmic (perivitelline space, zona pellucida thickness, oocyte shape, and polar bodies), have been proposed to distinguish oocytes with the best reproductive potential among a cohort. No single abnormality seems to be sufficiently predictive of the developmental capacity of the oocyte. Some abnormalities such as cumulus cells dysmorphisms, central granulation, vacuoles, and smooth endoplasmic reticulum clusters, however, seem to be associated with poor developmental potential of the embryo, although oocyte dysmorphisms are very common and the data in the literature is limited and provide conflicting views. Other criteria involving gene expression of cumulus cells as well as the metabolomic analysis of spent culture media have been explored. Also, sophisticated technologies such as polar bodies biopsy, meiotic spindle visualization, mitochondrial activity, oxygen consumption, and measurement of glucose-6-phosphate dehydrogenase activity have been proposed. Many of these approaches, however, remain largely research-based and have not found widespread application in clinical service. Due to the lack of consistent data for the assessment of oocyte quality and competence, probably oocyte morphology and oocyte maturity remain important indicators to determine oocyte quality. The aim of this review was to provide spherical attributes and evidence on recent and present research on the topic by analyzing the current methods for evaluation of the oocyte quality, and the impact of oocyte quality on reproductive outcomes. Additionally, current limitations of oocyte quality evaluation are highlighted and insights on future research are provided to optimize the selection techniques of oocytes to improve ART outcomes.

Bridging the Gap between AZF Microdeletions and Karyotype: Twelve Years' Experience of an Infertility Center.

PURPOSE: Despite all past efforts, the current guidelines are not explicit enough regarding the indications for performing azoospermia factor (AZF) screening and karyotype, burdening clinicians with the decision to assess whether such tests are meaningful for the infertile male patient. These assessments can be costly and it is up to the healthcare practitioner to decide which are necessary and to weigh the benefits against economic/psychological harm. The aim of this study is to address such gaps and provide update on current management options for this group of patients. MATERIALS AND METHODS: To address such gaps in male infertility management and to elucidate whether AZF screening is indicated in individuals who concomitantly harbor chromosomal abnormalities we conducted a retrospective cohort analysis of 10,388 consecutive patients with non-obstructive azoospermia (NOA) and severe oligozoospermia. RESULTS: Previously, it has been suggested that all NOA cases with chromosomal defects, except males with 46,XY/45,X karyotype, have no indication for AZF screening. Our findings revealed that cases carrying the following chromosomal abnormalities inv(Y)(p11.2q12); idic(Y)(q11.2); 46,XY,r(Y); idic(Y)(p11.2) and der(Y;Autosome) (76/169; 44.9%; 95% CI, 37.7-52.5) should also be referred for AZF deletion screening. Here, we also report the correlation between sperm count and AZF deletions as a secondary outcome. In accordance with previously reported data from North America and Europe, our data revealed that only 1% of cases with >1×106 sperm/mL had Y chromosome microdeletions (YCMs). CONCLUSIONS: In the era of assisted reproduction, finding cost-minimization strategies in infertility clinics without affecting the quality of diagnosis is becoming one of the top prioritized topics for future research. From a diagnostic viewpoint, the results reflect a need to reconsider the different karyotype presentations and the sperm count thresholds in male infertility guidelines as indicators for YCM screening during an infertility evaluation.

Commercially Available Molecular Approaches to Evaluate Endometrial Receptivity: A Systematic Review and Critical Analysis of the Literature.

Despite the advances in the field of reproductive medicine, implantation failure represents a challenging condition affecting 10-30% of patients subjected to in vitro fertilization (IVF). Research has focused on the identification of molecules playing crucial roles in endometrial receptivity, with the aim of designing predictive tools for efficient detection of the implantation window. To that end, novel molecular genomic and transcriptomic approaches have been introduced as promising tools to enable personalized approaches with the aim of optimizing embryo transfer dating. However, the clinical value of these approaches remains unclear. The aim of this study is to provide a systematic review and critical analysis of the existing evidence regarding the employment of commercially available novel approaches to evaluate endometrial receptivity. An Embase and PubMed/Medline search was performed on 1 February 2022. From the 475 articles yielded, only 27 were included and analyzed. The considerable heterogeneity of the included articles indicates the uniqueness of the implantation window, showcasing that the optimal time for embryo transfer varies significantly between women. Moreover, this study provides information regarding the technical aspects of these advanced molecular tools, as well as an analysis of novel possible biomarkers for endometrial receptivity, providing a basis for future research in the field.

Predictive value of seminal oxidation-reduction potential analysis for reproductive outcomes of ICSI.

RESEARCH QUESTION: Is seminal oxidation-reduction potential (ORP) clinically relevant to reproductive outcome? DESIGN: Prospective observational study including a total of 144 couples who had an intracytoplasmic sperm injection (ICSI) cycle between June 2018 and December 2020. The study included patients undergoing fresh ICSI cycles with autologous gametes. Cycles that had day 3 embryo transfers and cryopreservation cycles were excluded. There was no restriction on patients with severe male infertility; couples with unexplained infertility and unexplained male infertility were included, those with azoospermia were excluded. Semen analysis, seminal ORP as determined by means of the MiOXSYS system, sperm DNA fragmentation (SDF) and reproductive outcomes (fertilization, blastocyst development, clinical pregnancy and live birth) were determined. RESULTS: Seminal ORP was significantly negatively correlated with fertilization rate (r = -0.267; P = 0.0012), blastocyst development rate (r = -0.432; P < 0.0001), implantation/clinical pregnancy (r = -0.305; P = 0.0003) and live birth (r = -0.366; P < 0.0001). Receiver operating characteristic curve analysis showed significant predictive power for ORP for fertilization (≥80%; area under the curve [AUC] 0.652; P = 0.0012), blastocyst development rate (≥60%; AUC 0.794; P < 0.0001), implantation/clinical pregnancy (AUC 0.680; P = 0.0002) and live birth (AUC 0.728; P < 0.0001). Comparable results were obtained for SDF (fertilization: AUC 0.678; blastocyst development: AUC 0.777; implantation/clinical pregnancy: AUC 0.665; live birth: AUC 0.723). Normal sperm morphology showed the lowest predictive power for all reproductive outcome parameters. With male age as confounding factor, ORP (cut-off value of 0.51 mV/106 sperm/ml) has significant (P < 0.04667) effects on odds ratios for all reproductive outcome parameters. Multivariate logistic regression to investigate potential seminal and female confounding factors revealed that seminal ORP significantly (P < 0.0039; P < 0.0130) affects reproductive outcome. CONCLUSION: Seminal ORP is relevant for good fertilization, blastocyst development, implantation, clinical pregnancy and live birth.

Sperm DNA integrity and male infertility: a narrative review and guide for the reproductive physicians.

Background and Objective: Conventional semen analysis (SA) remains an essential tool in the initial male fertility evaluation and subsequent follow-up. However, it neither provides information about the functional status of spermatozoa nor addresses disorders such as idiopathic or unexplained infertility (UI). Recently, assessment of sperm DNA fragmentation (SDF) has been proposed as an extended sperm test that may help overcome these inherent limitations of basic SA. In this review, we aim to: (I) discuss the pathophysiological aspects of SDF, including natural repair mechanisms, causes, and impact on reproductive outcomes; (II) explain different assessment tools of SDF, and describe potential therapeutic options to manage infertile men with high SDF; and (III) analyse the strengths, weaknesses, opportunities and threats (SWOT) of current research on the topic. Methods: This review was constructed from original studies, systematic reviews and meta-analyses that were published over the years up until August 2021, related to the various aspects of SDF. Key Content and Findings: Different mechanisms lead to high SDF, including defective chromatin packaging, apoptosis, and seminal oxidative stress. The relevance of sperm DNA integrity to male fertility/infertility has been supported by the frequent observation of high levels of SDF in infertile men, and in association with risk factors for infertility. Additionally, high SDF levels have been inversely correlated with the outcomes of natural pregnancy and assisted reproduction. Terminal deoxynucleotidyl transferase dUTP nick end labelling, sperm chromatin structure assay, sperm chromatin dispersion, and Comet assay are four commonly used assays for measurement of SDF. Addressing lifestyle risks and underlying conditions, antioxidants, hormonal therapy, and advanced sperm selection techniques have all been proposed as potential therapeutic options to lower SDF. Conclusions: The sum of literature provides evidence of detrimental effects of high SDF on both natural and assisted fertility outcomes. Standardization of the techniques used for assessment of SDF and their incorporation into the work up of infertile couples may have significant implications on the future management of a selected category of infertile men with high SDF.

Reply to Pallotti et al. Comment on "Boitrelle et al. The Sixth Edition of the WHO Manual for Human Semen Analysis: A Critical Review and SWOT Analysis. Life 2021, 11, 1368".

We would like to thank F. Pallotti and his colleagues for their positive comments [...].

Sperm Vitality and Necrozoospermia: Diagnosis, Management, and Results of a Global Survey of Clinical Practice.

Sperm vitality testing is a basic semen examination that has been described in the World Health Organization (WHO) Laboratory Manual for the Examination and Processing of Human Semen from its primary edition, 40 years ago. Several methods can be used to test sperm vitality, such as the eosin-nigrosin (E-N) stain or the hypoosmotic swelling (HOS) test. In the 6th (2021) edition of the WHO Laboratory Manual, sperm vitality assessment is mainly recommended if the total motility is less than 40%. Hence, a motile spermatozoon is considered alive, however, in certain conditions an immotile spermatozoon can also be alive. Therefore, the differentiation between asthenozoospermia (pathological decrease in sperm motility) and necrozoospermia (pathological decrease in sperm vitality) is important in directing further investigation and management of infertile patients. The causes leading to necrozoospermia are diverse and can either be local or general, testicular or extra-testicular. The andrological management of necrozoospermia depends on its etiology. However, there is no standardized treatment available presently and practice varies among clinicians. In this study, we report the results of a global survey to understand current practices regarding the physician order of sperm vitality tests as well as the management practices for necrozoospermia. Laboratory and clinical scenarios are presented to guide the reader in the management of necrozoospermia with the overall objective of establishing a benchmark ranging from the diagnosis of necrozoospermia by sperm vitality testing to its clinical management.

A Comprehensive Guide to Sperm Recovery in Infertile Men with Retrograde Ejaculation.

Retrograde ejaculation (RE) is a condition defined as the backward flow of the semen during ejaculation, and when present can result in male infertility. RE may be partial or complete, resulting in either low seminal volume or complete absence of the ejaculate (dry ejaculate). RE can result from anatomic, neurological or pharmacological conditions. The treatment approaches outlined are determined by the cause. Alkalinizing urinary pH with oral medications or by adding sperm wash media into the bladder prior to ejaculation may preserve the viability of the sperm. This article provides a step-by-step guide to diagnose RE and the optimal techniques to retrieve sperm.

Relevance of Leukocytospermia and Semen Culture and Its True Place in Diagnosing and Treating Male Infertility.

The current WHO 2010 manual for human semen analysis defines leukocytospermia as the presence of peroxidase-positive leukocytes at a concentration >1×106/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.

Sperm Morphology Assessment in the Era of Intracytoplasmic Sperm Injection: Reliable Results Require Focus on Standardization, Quality Control, and Training.

Semen analysis is the first, and frequently, the only step in the evaluation of male fertility. Although the laboratory procedures are conducted according to the World Health Organization (WHO) guidelines, semen analysis and especially sperm morphology assessment is very difficult to standardize and obtain reproducible results. This is mainly due to the highly subjective nature of their evaluation. ICSI is the choice of treatment when sperm morphology is severely abnormal (teratozoospermic). Hence, the standardization of laboratory protocols for sperm morphology evaluation represents a fundamental step to ensure reliable, accurate and consistent laboratory results that avoid misdiagnoses and inadequate treatment of the infertile patient. This article aims to promote standardized laboratory procedures for an accurate evaluation of sperm morphology, including the establishment of quality control and quality assurance policies. Additionally, the clinical importance of sperm morphology results in assisted reproductive outcomes is discussed, along with the clinical management of teratozoospermic patients.

Male Age and Progressive Sperm Motility Are Critical Factors Affecting Embryological and Clinical Outcomes in Oocyte Donor ICSI Cycles.

This retrospective cohort study aimed to explore whether paternal age and semen quality parameters affect the embryological and clinical outcomes of ICSI with oocyte donation. A total of 339 oocyte donation (OD)-ICSI cycles were categorized into four groups according to the semen parameter profiles of the male counterparts: normozoospermia (NS, n = 184), oligozoospermia (OS, n = 41), asthenozoospermia (AS, n = 50), and oligoasthenozoospermia (OAS, n = 64). The effect of age, total sperm count, and progressive motility was separately analyzed for reproductive outcomes and compared between the study groups: fertilization, blastulation, and top-quality embryo rate, biochemical and clinical pregnancy, live birth, and miscarriage. A negative correlation between male age and fertilization rate was observed (rs = - 0.23, p < 0.0001), while male age was a significant factor for biochemical pregnancy (p = 0.0002), clinical pregnancy (p = 0.0017), and live birth (p = 0.0038). Reduced total sperm count and lowered progressive motility led to poorer fertilization rates (rs = 0.19 and 0.35, respectively, p < 0.0001) and affected embryo quality (rs = 0.13, p = 0.02, and rs = 0.22, p < 0.0001, respectively). OD-ICSI cycles with asthenozoospermia had significantly lowered success rates in biochemical pregnancy, clinical pregnancy, and live birth (p < 0.05). Our study demonstrated that both advanced male age and reduced progressive motility of spermatozoa exert a significant negative influence on the outcome of assisted reproduction, even in controlled procedures with gamete selection and optimization such as in OD-ICSI. Improvement in treatment strategies and male fertility evaluation requires incorporation of such evidence to obtain better prognosis towards personalized management.

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.