Evolution of the World Health Organization semen analysis manual: where are we?

A multi-faceted exploration of unmet needs in the continuing improvement and development of fertility care amidst a pandemic

PURPOSE

The continuous improvement and development of fertility care, internationally, requires ongoing monitoring of current delivery processes and outcomes in clinical practice. This descriptive and exploratory mixed-methods study was conducted in eight countries (Brazil, China, France, Germany, Italy, Mexico, Spain and the United Kingdom) to assess the unmet needs of fertility patients (male and female), and existing challenges, barriers and educational gaps of physicians and laboratory specialists involved in human fertility care during the COVID-19 pandemic.

MATERIALS AND METHODS

The study was deployed sequentially in two phases: 1) in-depth 45-minute semi-structured interviews (n=76), transcribed, coded and thematically analysed using an inductive reasoning approach, 2) an online survey (n=303) informed by the findings of the qualitative interviews, face validated by experts in reproductive medicine, and analysed using descriptive and inferential statistical methods.

RESULTS

The integrated results of both phases indicated numerous areas of challenges, including: 1) investigating male-related infertility; 2) deciding appropriate treatment for men and selective use of assisted reproductive technology; and 3) maintaining access to high-quality fertility care during a pandemic.

CONCLUSIONS

The paper presents a reflective piece on knowledge and skills that warrant ongoing monitoring and improvement amongst reproductive medicine healthcare professionals amidst future pandemics and unanticipated health system disruptions. Moreover, these findings suggest that there is an additional need to better understand the required changes in policies and organizational processes that would facilitate access to andrology services for male infertility and specialized care, as needed.

From pathophysiology to practice: addressing oxidative stress and sperm DNA fragmentation in Varicocele-affected subfertile men

Varicocele can reduce male fertility potential through various oxidative stress mechanisms. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress, damaging the sperm chromatin. Sperm DNA fragmentation, in the form of DNA strand breaks, is recognized as a consequence of the oxidative stress cascade and is commonly found in the ejaculates of men with varicocele and fertility issues. This paper reviews the current knowledge regarding the association between varicocele, oxidative stress, sperm DNA fragmentation, and male infertility, and examines the role of varicocele repair in alleviating oxidative-sperm DNA fragmentation in these patients. Additionally, we highlight areas for further research to address knowledge gaps relevant to clinical practice.

Weight Loss as Therapeutic Option to Restore Fertility in Obese Men: A Meta-Analytic Study

PURPOSE

Weight loss has been shown to significantly elevate testosterone serum levels, though the impact on semen analysis parameters and fertility remains incompletely understood. The objective of this study was to examine the influence of body weight loss on semen parameters in obese men.

MATERIALS AND METHODS

A meta-analysis was performed that included clinical trials in which a semen analysis before and after weight loss was evaluated. All strategies potentially available for weight loss were considered eligible. The primary outcome was the comparison of conventional semen analysis parameters before and after weight loss.

RESULTS

Twelve studies were considered including 345 subjects (mean age 37.6±7.9 years; mean baseline body mass index 45.4±6.0 kg/m²). Weight loss resulted in a significant increase of sperm concentration (effect size 0.495, standard error 0.251 [0.003, 0.986], p=0.049) and progressive motility (effect size 0.567, standard error 0.372 [0.370, 0.764], p<0.001). Moreover, a significant decrease of sperm DNA fragmentation index after weight loss (effect size -0.689, standard error 0.278 [-1.123, -0.255], p=0.002) was observed.

CONCLUSIONS

This meta-analytic analysis confirmed that body weight loss may improve qualitative and quantitative sperm characteristics providing evidence for suggesting weight loss to male partners with obesity and semen analysis alteration in couples attempting conception.

Non-Obstructive Azoospermia and Intracytoplasmic Sperm Injection: Unveiling the Chances of Success and Possible Consequences for Offspring

Non-obstructive azoospermia (NOA) is found in up to 15% of infertile men. While several causes for NOA have been identified, the exact etiology remains unknown in many patients. Advances in assisted reproductive technology, including intracytoplasmic sperm injection (ICSI) and testicular sperm retrieval, have provided hope for these patients. This review summarizes the chances of success with ICSI for NOA patients and examines preoperative factors and laboratory techniques associated with positive outcomes. Furthermore, we reviewed possible consequences for offspring by the use of ICSI with testicular sperm retrieved from NOA patients and the interventions that could potentially mitigate risks. Testicular sperm retrieved from NOA patients may exhibit increased chromosomal abnormalities, and although lower fertilization and pregnancy rates are reported in NOA patients compared to other forms of infertility, the available evidence does not suggest a significant increase in miscarriage rate, congenital malformation, or developmental delay in their offspring compared to the offspring of patients with less severe forms of infertility or the offspring of fertile men. However, due to limited data, NOA patients should receive specialized reproductive care and personalized management. Counseling of NOA patients is essential before initiating any fertility enhancement treatment not only to mitigate health risks associated with NOA but also to enhance the chances of successful outcomes and minimize possible risks to the offspring.

Cryopreserved testicular spermatozoa among patients with azoospermia

PURPOSE

To investigate cryopreserved testicular spermatozoa among patients with azoospermia.

METHODS

In this retrospective study spanning from October 1993 to December 2021, we examined men diagnosed with azoospermia who underwent testicular spermatozoa cryopreservation. Data from medical records included utilization and disposal of sperm samples, age at initial cryopreservation. We analyzed the data over 20 years using Kaplan-Meier curves, compared age with the log-rank test, and assessed hazard ratios (HR) with 95% confidence intervals (CI) using Cox regression analysis.

RESULTS

A total of 356 patients with a mean age of 32.1 ± 6 were included. Of these, 225 patients utilized thawed testicular sperm for fertility treatments, with 118 patients using all their frozen straws and 107 patients partially using their stored straws. Additionally, 29 patients opted for disposal (six patients partially used their testicular spermatozoa before disposal), resulting in 108 patients who neither used nor disposed of their straws. From a laboratory standpoint, nearly 90% of patients contributed a single testicular sample, which was subsequently divided and cryopreserved as straws, with a median of 4 straws per sample. Notably, in the older age group (> 35 years old), there were a significantly lower usage rate and a higher disposal rate compared to the younger age groups (p < 0.05 for both), corroborated by univariable Cox analysis.

CONCLUSIONS

This extensive study unveils unique patterns in the preservation and disposal of testicular spermatozoa among azoospermic patients. Most patients utilize a significant portion of their stored samples, while older patients tend to use their testicular spermatozoa less frequently.

APHRODITE criteria: addressing male patients with hypogonadism and/or infertility owing to altered idiopathic testicular function

RESEARCH QUESTION

Can a novel classification system of the infertile male - 'APHRODITE' (Addressing male Patients with Hypogonadism and/or infeRtility Owing to altereD, Idiopathic TEsticular function) - stratify different subgroups of male infertility to help scientists to design clinical trials on the hormonal treatment of male infertility, and clinicians to counsel and treat the endocrinological imbalances in men and, ultimately, increase the chances of natural and assisted conception?

DESIGN

A collaboration between andrologists, reproductive urologists and gynaecologists, with specialization in reproductive medicine and expertise in male infertility, led to the development of the APHRODITE criteria through an iterative consensus process based on clinical patient descriptions and the results of routine laboratory tests, including semen analysis and hormonal testing.

RESULTS

Five patient groups were delineated according to the APHRODITE criteria; (1) Hypogonadotrophic hypogonadism (acquired and congenital); (2) Idiopathic male infertility with lowered semen analysis parameters, normal serum FSH and normal serum total testosterone concentrations; (3) A hypogonadal state with lowered semen analysis parameters, normal FSH and reduced total testosterone concentrations; (4) Lowered semen analysis parameters, elevated FSH concentrations and reduced or normal total testosterone concentrations; and (5) Unexplained male infertility in the context of unexplained couple infertility.

CONCLUSION

The APHRODITE criteria offer a novel and standardized patient stratification system for male infertility independent of aetiology and/or altered spermatogenesis, facilitating communication among clinicians, researchers and patients to improve reproductive outcomes following hormonal therapy. APHRODITE is proposed as a basis for future trials of the hormonal treatment of male infertility.

Effect of environmental factors on seminal microbiome and impact on sperm quality

Objective

This review provides a comprehensive overview of the existing research on the seminal microbiome and its association with male infertility, while also highlighting areas that warrant further investigation.

Methods

A narrative review was conducted, encompassing all relevant studies published between 1980-2023 on the male reproductive tract microbiome in humans. This review considered studies utilizing culture-based, polymerase chain reaction (PCR)-based, and next-generation sequencing (NGS)-based methodologies to analyze the microbiome. Data extraction encompassed sample types (semen or testicular tissue), study designs, participant characteristics, employed techniques, and critical findings.

Results

We included 37 studies comprising 9,310 participants. Among these, 16 studies used culture-based methods, 16 utilized NGS, and five employed a combination of methods for microorganism identification. Notably, none of the studies assessed fungi or viruses. All NGS-based studies identified the presence of bacteria in all semen samples. Two notable characteristics of the seminal microbiome were observed: substantial variability in species composition among individuals and the formation of microbial communities with a dominant species. Studies examining the testicular microbiome revealed that the testicular compartment is not sterile. Interestingly, sexually active couples shared 56% of predominant genera, and among couples with positive cultures in both partners, 61% of them shared at least one genital pathogen. In couples with infertility of known causes, there was an overlap in bacterial composition between the seminal and vaginal microbiomes, featuring an increased prevalence of Staphylococcus and Streptococcus genera. Furthermore, the seminal microbiome had discernible effects on reproductive outcomes. However, bacteria in IVF culture media did not seem to impact pregnancy rates.

Conclusion

Existing literature underscores that various genera of bacteria colonize the male reproductive tract. These organisms do not exist independently; instead, they play a pivotal role in regulating functions and maintaining hemostasis. Future research should prioritize longitudinal and prospective studies and investigations into the influence of infertility causes and commonly prescribed medication to enhance our understanding of the seminal microbiota's role in reproductive health.

Effect of varicocele and varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele

Varicocele is the leading cause of male infertility. It can affect sperm quantity and quality through various non-mutually exclusive pathophysiological mechanisms, mainly oxidative stress. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress and harm the sperm's DNA. Excessive sperm DNA breaks, so-called sperm DNA fragmentation, result from the oxidative stress cascade and are commonly found in the ejaculates of men with varicocele and fertility-related issues. Measuring sperm DNA fragmentation can provide valuable information on the extent of harm and might help select candidates for surgical treatment. Varicocelectomy is beneficial for alleviating oxidative stress-associated infertility and improving sperm DNA integrity. However, reproductive outcomes of infertile men with elevated sperm DNA fragmentation rates and surgically treated varicoceles remain poorly studied, and there is a need for well-designed trials to determine the impact of sperm DNA fragmentation reduction on natural and medically assisted reproduction.

Frequency, morbidity and equity - the case for increased research on male fertility

Currently, most men with infertility cannot be given an aetiology, which reflects a lack of knowledge around gamete production and how it is affected by genetics and the environment. A failure to recognize the burden of male infertility and its potential as a biomarker for systemic illness exists. The absence of such knowledge results in patients generally being treated as a uniform group, for whom the strategy is to bypass the causality using medically assisted reproduction (MAR) techniques. In doing so, opportunities to prevent co-morbidity are missed and the burden of MAR is shifted to the woman. To advance understanding of men's reproductive health, longitudinal and multi-national centres for data and sample collection are essential. Such programmes must enable an integrated view of the consequences of genetics, epigenetics and environmental factors on fertility and offspring health. Definition and possible amelioration of the consequences of MAR for conceived children are needed. Inherent in this statement is the necessity to promote fertility restoration and/or use the least invasive MAR strategy available. To achieve this aim, protocols must be rigorously tested and the move towards personalized medicine encouraged. Equally, education of the public, governments and clinicians on the frequency and consequences of infertility is needed. Health options, including male contraceptives, must be expanded, and the opportunities encompassed in such investment understood. The pressing questions related to male reproductive health, spanning the spectrum of andrology are identified in the Expert Recommendation.

Epigenetic determinants of reproductive potential augment the predictive ability of the semen analysis

OBJECTIVE

To investigate the power of DNA methylation variability in sperm cells in assessing male fertility potential.

DESIGN

Retrospective cohort.

SETTING

Fertility care centers.

PATIENTS

Male patients seeking infertility treatment and fertile male sperm donors.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Sperm DNA methylation data from 43 fertile sperm donors were analyzed and compared with the data from 1344 men seeking fertility assessment or treatment. Methylation at gene promoters with the least variable methylation in fertile patients was used to create 3 categories of promoter dysregulation in the infertility treatment cohort: poor, average, and excellent sperm quality.

RESULTS

After controlling for female factors, there were significant differences in intrauterine insemination pregnancy and live birth outcomes between the poor and excellent groups across a cumulative average of 2-3 cycles: 19.4% vs. 51.7% (P=.008) and 19.4% vs. 44.8% (P=.03), respectively. Live birth outcomes from in vitro fertilization, primarily with intracytoplasmic sperm injection, were not found to be significantly different among any of the 3 groups.

CONCLUSION

Methylation variability in a panel of 1233 gene promoters could augment the predictive ability of semen analysis and be a reliable biomarker for assessing intrauterine insemination outcomes. In vitro fertilization with intracytoplasmic sperm injection appears to overcome high levels of epigenetic instability in sperm.

Can semen parameters predict pregnancy outcomes?

Semen analysis is an integral component of the evaluation and management of men with infertility. Although it is important for patient counseling and clinical decision making, a conventional semen analysis cannot reliably predict the chance of pregnancy or differentiate fertile vs. infertile men (except in the most extreme cases). Advanced, nonstandard sperm functional tests may provide additional discriminatory and prognostic power; however, further research is needed to determine how to best incorporate these tests into modern clinical practice. Therefore, the primary applications of a conventional semen analysis should be to judge the severity of infertility, estimate the effects of future therapy, and measure the response to current therapy.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Elevated estradiol levels on hCG trigger day adversely effects on the clinical pregnancy rates of blastocyst embryo transfer but not cleavage-stage embryo transfer in fresh cycles: a retrospective cohort study

Background

Elevated estradiol (E₂) levels are an inevitable outcome of the controlled ovulation hyperstimulation. However, the effect of this change on pregnancy is still uncertain. Our study aimed to analyze the impact of increased serum E₂ at the day of human chorionic gonadotropin (hCG) administration on the clinical outcomes of women with fresh embryo transfer (ET) cycles.

Methods

This study included 3,009 fresh ET cycles from October 2015 to September 2021. Based on the stage of embryos transferred, these cycles were categorized into the cleavage group and blastocyst group. Both groups were then divided into four sets according to E₂ levels when hCG was administered: set 1 (E₂ ≤ 2,000 pg/ml), set 2 (E₂ = 2,001-3,000 pg/ml), set 3 (E₂ = 3,001-4,000 pg/ml), and set 4 (E₂ > 4,000 pg/ml). The primary outcome was the clinical pregnancy rate (CPR). Binary logistics regression analysis was established to explore the association between CPR and E2 levels. Specifically, the threshold effect of serum E2 on CPR was revealed using the two-piecewise linear regression analyses.

Results

The multivariate regression model in the cleavage group showed that patients' CPR in set 4 was 1.59 times higher than those in reference set 1, but the statistical difference was insignificant (P = 0.294). As for the blastocyst group, patients in set 4 had a lower CPR with adjusted ORs of 0.43 (P = 0.039) compared to patients in set 1. The inflection point for the blastocyst group was 39.7 pg/dl according to the results of the two-piecewise linear regression model. When E₂ levels were over the point, the CPR decreased by 17% with every 1 pg/dl increases in serum E₂ (adjusted OR = 0.83, 95% CI [0.72-0.96], P = 0.012).

Conclusions

Elevated E₂ levels (>39.7 pg/dl) on hCG trigger day were associated with decreased CPR in patients with fresh blastocyst ET. However, it had no similar effect on the CPR of patients with fresh cleavage-stage ET.

Towards infertility care on equal terms: a prime time for male infertility

Male infertility is a disease that deserves greater clinical attention and research. A universally accepted definition that emphasizes the modulatory impact of age, lifestyle and environmental factors and includes comprehensive diagnostic and treatment guidelines is needed to ensure accurate evaluation and effective care. Accordingly, male infertility should be defined as a disease of the male reproductive system, caused primarily by congenital and genetic conditions, anatomical, endocrine, functional or immunological abnormalities of the reproductive system, genital tract infections, cancer and its related treatments, and sexual disorders incompatible with intercourse. Inadequate lifestyle, exposure to toxicants and advanced paternal age are critical factors acting alone or exacerbating the impact of known causative factors. The focus on male infertility must be balanced with that on female infertility to ensure the best possible outcome for the couple. Fertility clinics are encouraged to prioritize collaboration with reproductive urologists and andrologists to provide the best possible care for male infertility patients.

Male infertility and gonadotropin treatment: What can we learn from real-world data?

Gonadotropin therapy to treat specific male infertility disorders associated with hypogonadotropic hypogonadism is evidence-based and effective in restoring spermatogenesis and fertility. In contrast, its use to improve fertility in men with idiopathic oligozoospermia or nonobstructive azoospermia remains controversial, despite being widely practiced. The existence of two major inter-related pathways for spermatogenesis, including FSH and intratesticular testosterone, provides a rationale for empiric hormone stimulation therapy in both eugonadal and hypogonadal males with idiopathic oligozoospermia or nonobstructive azoospermia. Real-world data (RWD) on gonadotropin stimulating for these patient subsets, mainly using human chorionic gonadotropin and follicle-stimulating hormone, accumulated gradually, showing a positive therapeutic effect in some patients, translated by increased sperm production, sperm quality, and sperm retrieval rates. Although more evidence is needed, current insights from RWD research indicate that selected male infertility patients might be managed more effectively using gonadotropin therapy, with potential gains for all parties involved.

New horizons in human sperm selection for assisted reproduction

Male infertility is a commonly encountered pathology that is estimated to be a contributory factor in approximately 50% of couples seeking recourse to assisted reproductive technologies. Upon clinical presentation, such males are commonly subjected to conventional diagnostic andrological practices that rely on descriptive criteria to define their fertility based on the number of morphologically normal, motile spermatozoa encountered within their ejaculate. Despite the virtual ubiquitous adoption of such diagnostic practices, they are not without their limitations and accordingly, there is now increasing awareness of the importance of assessing sperm quality in order to more accurately predict a male's fertility status. This realization raises the important question of which characteristics signify a high-quality, fertilization competent sperm cell. In this review, we reflect on recent advances in our mechanistic understanding of sperm biology and function, which are contributing to a growing armory of innovative approaches to diagnose and treat male infertility. In particular we review progress toward the implementation of precision medicine; the robust clinical adoption of which in the setting of fertility, currently lags well behind that of other fields of medicine. Despite this, research shows that the application of advanced technology platforms such as whole exome sequencing and proteomic analyses hold considerable promise in optimizing outcomes for the management of male infertility by uncovering and expanding our inventory of candidate infertility biomarkers, as well as those associated with recurrent pregnancy loss. Similarly, the development of advanced imaging technologies in tandem with machine learning artificial intelligence are poised to disrupt the fertility care paradigm by advancing our understanding of the molecular and biological causes of infertility to provide novel avenues for future diagnostics and treatments.