The other side of COVID-19 pandemic: Effects on male fertility

The association between COVID-19 and infertility: Mendelian randomization analysis

Since December 2019, COVID-19 has triggered a global pandemic. The association of COVID-19 with the long-term reproductive situation of women and males is not clear. Thus, our aim was to assess the causal association between COVID-19 and infertility using Mendelian randomization (MR) analysis based on the OpenGWAS database. Two-sample MR analysis was conducted using one genome-wide association study (GWAS) on COVID-19 and infertility in individuals of European ancestry. The summary data of genetic variation come from the GWAS in European populations. We applied several MR methods, including MR Egger, weighted median, inverse variance weighted, simple mode, weighted mode, to test causal relationships. After observing the statistical analysis results of MR, we conducted sensitivity analysis to test robustness. After gene prediction, it was found that there was no clear causal relationship between COVID-19 and male infertility in MR analysis [OR 0.4702 (95% CI, 0.1569-1.4093), P = .178]. Moreover, COVID-19 was not associated with female infertility [OR 0.9981 (95% CI, 0.763-1.544), P = .646]. Sensitivity analysis showed that the MR results were robust [level pleiotropy, male: (MR-Egger, intercept = 0.1967434; se = 0.1186876; P = .2392406); female: (MR-Egger, intercept = -0.05902506; se = 0.05362049; P = .3211367)]. To further validate the impact of COVID-19 on infertility, we added a covariate (sex hormone binding global levels, abortion) to the MR analysis, which is a multivariate MR analysis. According to univariate and multivariate MR analyses, the evidence does not support that COVID-19 is a causal risk factor for infertility in European population. This information can provide information for doctors in reproductive centers when managing infertility patients.

Infertility: A common target of antivaccine misinformation campaigns

Misinformation, disinformation, and conspiracy theories about vaccines are key drivers of vaccine hesitancy. A repeated false claim about COVID-19 vaccines is that the vaccines cause female infertility. Dating back decades, various conspiracy theories have linked vaccination programs with infertility and thus harmed vaccination programs in Africa, Asia, and Central America, particularly against polio and tetanus. In the United States, Europe, and Australia, human papilloma virus (HPV) vaccines have been falsely blamed for infertility and primary ovarian insufficiency (POI). After distribution of COVID-19 vaccines began in December 2020, almost immediately there arose conspiracy theories claiming that these vaccines cause menstrual irregularities, miscarriages, and infertility, promoted by noted antivaccine activists Robert F. Kennedy, Jr. and Andrew Wakefield among others. Here we will explore the history of this antivaccine narrative, how it has been promulgated in the past and repurposed to COVID-19 vaccines, and strategies to counter it.

Angiotensin-(1-7) plays an important role in regulating spermatogenesis in Trachemys scripta elegans under salinity stress

Elevation in water salinity can threaten the spermatogenesis and fertility of freshwater animals. The role of the renin-angiotensin system (RAS) in regulating spermatogenesis has attracted considerable attention. Our previous study found that red-eared sliders (Trachemys scripta elegans), could survive in 10 PSU water for over 1 year. To understand the chronic impact of salinity on testicular spermatogenesis and underlying mechanisms, male T. s. elegans were subjected to treatment with water of 5 PSU and 10 PSU for a year, and spermatogenesis and regulation of the RAS signal pathway was assessed. Results showed induced inflammation in the testes of T. s. elegans in the 10 PSU group, as evidenced by a decrease in the number of testicular germ cells from 1586 to 943. Compared with the control group, the levels of proinflammatory genes, including TNF-α, IL-12A and IL-6 were elevated 3.1, 0.3, and 1.4 times, respectively, in animals exposed to 10 PSU water. Testicular antiapoptotic processes of T. s. elegans might involve the vasoactive peptide angiotensin-(1-7) in the RAS, as its level was significantly increased from 220.2 ng ml-1 in controls to 419.2 ng ml-1 in the 10 PSU group. As expected, specific inhibitor (A-779) for the Ang-(1-7) acceptor effectively prevented the salinity-induced upregulation of genes encoding anti-inflammatory and antiapoptotic factors (TGF-β1, Bcl-6) in the testis of the 10 PSU animals, whereas it promoted the upregulation of proinflammatory and proapoptotic factors (TNF-α, IL-12A, IL-6, Bax and caspase-3). Our data indicated that Ang-(1-7) attenuates the effect of salinity on inflammation and apoptosis of the testis in T. s. elegans. A new perspective to prevent salinity-induced testis dysfunction is provided.

Effects of COVID-19 or vaccines for SARS-COV-2 on sperm parameters: A systematic review and meta-analysis

This systematic review and meta-analysis assessed the effects of SARS-Cov-2 and mRNA vaccines on male reproduction. We conducted a comprehensive search using terms such as "COVID-19," "vaccine," and "sperm parameters" on various electronic databases, including MEDLINE (PubMed), BVS (LILACS and others), Embase (Elsevier), and Cochrane Library. We included observational studies, including cohort, case-control, and cross-sectional studies. Of the 2054 records initially identified, we carefully examined 47 full-text articles and excluded 26 articles for specific reasons, ultimately including 21 studies for our analysis. Among these, 16 studies focused on assessing seminal parameters in patients with COVID-19, while five studies investigated the effects of COVID vaccines on seminal parameters. A meta-analysis of seminal parameters in men before and after the COVID-19 pandemic revealed significant differences in seminal concentration, progressive motility, total motility, and normal morphology. These findings indicate a positive impact of the analyzed parameters before the onset of COVID-19. However, the quality of the evidence was considered low. In contrast, a meta-analysis of five studies evaluating seminal parameters before and after the SARS-Cov-2 vaccine did not show any significant differences in total motility. This analysis, involving 256 men from four studies, provided low-quality evidence, suggesting that mRNA vaccines do not affect male reproduction. Overall, our findings suggest that seminal parameters exhibit considerable variability depending on specific outcomes and the study design. However, based on available evidence, it appears that mRNA vaccines do not have detrimental effects on male reproductive function.

Eif2s3y alleviated LPS-induced damage to mouse testis and maintained spermatogenesis by negatively regulating Adamts5

Eif2s3y (eukaryotic translation initiation factor 2, subunit 3, structural gene Y-linked, Eif2s3y) is an essential gene for spermatogenesis. Early studies have shown that Eif2s3y can promote the proliferation of spermatogonial stem cells (SSCs) and can replace the Y chromosome together with sex-determining region Y (Sry) to transform SSCs into round spermatozoa. We injected lentiviral particles into the seminiferous tubules of mouse testes by sterile surgery surgically to establish overexpressing Eif2s3y testes. And then the mice were intraperitoneally injected with LPS to established the model of testis inflammation. Through RNA sequencing, qRT-PCR analysis, Western blot, co-culture etc., we found that Eif2s3y alleviated LPS-induced damage in mouse testes and maintained spermatogenesis. In testes with Eif2s3y overexpression, the seminiferous tubules were more regularly organized after exposure to LPS compared with the control. Eif2s3y performs its function by negatively regulating Adamts5 (a disintegrin and metalloproteinase containing a thrombospondin-1 motif), an extracellular matrix-degrading enzyme. ADAMTS5 shows a disruptive effect when the testis is exposed to LPS. Overexpression of Eif2s3y inhibited the TLR4/NFκB signaling pathway in the testis in response to LPS. Generally, our research shows that Eif2s3y protects the testis from LPS and maintains spermatogenesis by negatively regulating Adamts5.

Endothelial dysfunction in autoimmune, pulmonary, and kidney systems, and exercise tolerance following SARS-CoV-2 infection

Long COVID is characterized by persistent symptoms beyond 3-months of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection that last for at least 2 months and cannot be explained by an alternative diagnosis. Autonomic, immunologic, endothelial, and hypercoagulation are implicated as possible mechanisms of long COVID symptoms. Despite recognition of the public health challenges posed by long COVID, the current understanding of the pathophysiological underpinnings is still evolving. In this narrative review, we explore the long-term effects of SARS-CoV-2 infection on T cell activation such as autoimmune disorders and endothelial cell dysfunction involving vascular impairments within pulmonary and renal architecture. We have described how endothelial dysfunction and vascular abnormalities may underscore findings of exercise intolerance by way of impaired peripheral oxygen extraction in individuals with long COVID.

The genetic associations of COVID-19 on genitourinary symptoms

Background

Recently emerged reports indicated that patients with coronavirus disease 2019 (COVID-19) might experience novo genitourinary symptoms after discharge. Nevertheless, the causal associations and underlying mechanisms remain largely unclear.

Methods

Genome-wide association study (GWAS) statistics for COVID-19 and 28 genitourinary symptoms with consistent definitions were collected from the COVID-19 Host Genetic Initiative, FinnGen, and UK Biobanks. Mendelian randomization (MR) analyses were applied to explore the causal effects of COVID-19 on genitourinary symptoms by selecting single-nucleotide polymorphisms as instrumental variables. Meta-analyses were conducted to evaluate the combined causal effect. Molecular pathways connecting COVID-19 and its associated disorders were evaluated by weighted gene co-expression network analysis (WGCNA) and enrichment analyses to extract insights into the potential mechanisms underlying the connection.

Results

The MR and meta-analyses indicated that COVID-19 was causally associated with increased risk for calculus of the lower urinary tract (LUTC, OR: 1.2984 per doubling in odds of COVID-19, 95% CI: 1.0752-1.5680, p = 0.007) and sexual dysfunction (SD, OR: 1.0931, 95% CI: 1.0292-1.1610, p = 0.004). Intriguingly, COVID-19 might exert a slight causal protective effect on the progression of urinary tract infections (UTIs) and bladder cancer (BLCA). These results were robust to sensitivity analyses. Bioinformatic analyses indicated that the inflammatory-immune response module may mediate the links between COVID-19 and its associated disorders at the molecular level.

Conclusions

In response to post-COVID-19 symptoms, we recommend that COVID-19 patients should strengthen the prevention of LUTC and the monitoring of sexual function. Meanwhile, the positive effects of COVID-19 on UTIs and BLCA should attach equal importance.

Evaluation and management of male genital tract infections in the setting of male infertility: an updated review

PURPOSE OF REVIEW

Male infertility may be secondary to male genital tract infection (MGTI) in an estimated 15% of cases. In the absence of overt clinical signs, evaluation for MGTI beyond semen analysis is not well established. Therefore, we review the literature on the evaluation and management of MGTI in the setting of male infertility.

RECENT FINDINGS

A set of international guidelines recommends semen culture and PCR testing, but the significance of positive results remains unclear. Clinical trials evaluating anti-inflammatory or antibiotic treatment report improvements in sperm parameters and leukocytospermia, but data on the effect on conception rates are lacking. Human papillomavirus (HPV) and the novel coronavirus (SARS-CoV-2) have been associated with poor semen parameters and decreased conception rates.

SUMMARY

The finding of leukocytospermia on semen analysis prompts further evaluation for MGTI, including focused physical examination. The role of routine semen culture is controversial. Treatment options include anti-inflammatories; frequent ejaculation; and antibiotics, which should not be used in the absence of symptoms or microbiological infection. SARS-CoV-2 represents a subacute threat to fertility that should be screened for in the reproductive history along with HPV and other viruses.

MMPs, ADAMs and ADAMTSs are associated with mammalian sperm fate

Metalloproteinases include matrix metalloproteinases and disintegrin metalloproteinases. They are important members of the ECM degradation and reconstruction process and are associated with tissue development and disease. The ECM is a three-dimensional network of large molecules consisting of a variety of proteins. It is a physical scaffold for organs, and all types of cells can be found within the ECM. The testicle, where sperm are produced, is an organ that is constantly in dynamic flux. Metalloproteinases can regulate testicular tissue development and the maturation of sperm by affecting the ECM. Metalloproteinase disorders can lead to cryptorchidism, azoospermia, poor semen quality and other diseases. As a member of the metalloproteinase family, ADAMTS plays an important role in testicular slippage to the scrotum. ADAM is involved in the fertilization process, and excessive MMP can damage the BTB. In the testis, metalloproteinase stability represents the stability of the extracellular microenvironment in which germ cells are located and is associated with reproductive function. Metalloproteinases have a definite relationship with male reproduction, but the underlying mechanism is still unclear. This paper summarizes the literature on various metalloproteinases in testicular tissue physiology and pathology to elucidate their role in reproductive function and male reproductive mechanisms.

Immunohistochemical Analysis of Spermatogenesis in Patients with SARS-CoV-2 Invasion in Different Age Groups

Based on studies that focused on the effect of SARS-CoV-2 on human tissues, not only pulmonary invasion was revealed, but also impaired testicular function. Thus, the study of the mechanisms of influence of SARS-CoV-2 on spermatogenesis is still relevant. Of particular interest is the study of pathomorphological changes in men of different age groups. The purpose of this study was to evaluate immunohistochemical changes in spermatogenesis during SARS-CoV-2 invasion in different age groups. In our study, for the first time, a cohort of COVID-19-positive patients of different age groups was collected, and the following were conducted––confocal microscopy of the testicles and immunohistochemical evaluation of spermatogenesis disorders in SARS-CoV-2 invasion with antibodies to the spike protein, the nucleocapsid protein of the SARS-CoV-2 virus, and angiotensin convertase type 2. An IHC study and confocal microscopy of testicular autopsies from COVID-19-positive patients revealed an increase in the number of S-protein- and nucleocapsid-positively stained spermatogenic cells, which indicates SARS-CoV-2 invasion into them. A correlation was found between the number of ACE2-positive germ cells and the degree of hypospermatogenesis, and in the group of patients with confirmed coronavirus infection older than 45 years, the decrease in spermatogenic function was more pronounced than in the cohort of young people. Thus, our study found a decrease in both spermatogenic and endocrine (Leydig cells) testicular functions in patients with COVID-19 infection. In the elderly, these changes were significantly higher than in the group of young patients.

Infection of SARS-CoV-2 causes severe pathological changes in mouse testis

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected more than 600 million people worldwide. Several organs including lung, intestine, and brain are infected by SARS-CoV-2. It has been reported that SARS-CoV-2 receptor angiotensin-converting enzyme-2 (ACE2) is expressed in human testis. However, whether testis is also affected by SARS-CoV-2 is still unclear. In this study, we generate a human ACE2 (hACE2) transgenic mouse model in which the expression of hACE2 gene is regulated by hACE2 promoter. Sertoli and Leydig cells from hACE2 transgenic mice can be infected by SARS-CoV-2 pseudovirus in vitro, and severe pathological changes are observed after injecting the SARS-CoV-2 pseudovirus into the seminiferous tubules. Further studies reveal that Sertoli and Leydig cells from hACE2 transgenic mice are also infected by authentic SARS-CoV-2 virus in vitro. After testis interstitium injection, authentic SARS-CoV-2 viruses are first disseminated to the interstitial cells, and then detected inside the seminiferous tubules which in turn cause germ cell loss and disruption of seminiferous tubules. Our study demonstrates that testis is most likely a target of SARS-CoV-2 virus. Attention should be paid to the reproductive function in SARS-CoV-2 patients.

The Role of Mononuclear Phagocytes in the Testes and Epididymis

The mononuclear phagocytic system (MPS) is the primary innate immune cell group in male reproductive tissues, maintaining the balance of pro-inflammatory and immune tolerance. This article aims to outline the role of mononuclear macrophages in the immune balance of the testes and epididymis, and to understand the inner immune regulation mechanism. A review of pertinent publications was performed using the PubMed and Google Scholar databases on all articles published prior to January 2021. Search terms were based on the following keywords: 'MPS', 'mononuclear phagocytes', 'testes', 'epididymis', 'macrophage', 'Mφ', 'dendritic cell', 'DC', 'TLR', 'immune', 'inflammation', and 'polarization'. Additionally, reference lists of primary and review articles were reviewed for other publications of relevance. This review concluded that MPS exhibits a precise balance in the male reproductive system. In the testes, MPS cells are mainly suppressed subtypes (M2 and cDC2) under physiological conditions, which maintain the local immune tolerance. Under pathological conditions, MPS cells will transform into M1 and cDC1, producing various cytokines, and will activate T cell specific immunity as defense to foreign pathogens or self-antigens. In the epididymis, MPS cells vary in the different segments, which express immune tolerance in the caput and pro-inflammatory condition in the cauda. Collectively, MPS is the control point for maintaining the immune tolerance of the testes and epididymis as well as for eliminating pathogens.

The impact of asymptomatic and mild COVID-19 on sperm characteristics

Background: Although the pandemic of the new coronavirus infection (COVID-19) is characterized by mostly mild and asymptomatic cases (more than 80%), it appears important to assess the potential risks for the male reproductive system, in particular, for the parameters of the sperm. Aim: To study the effect of a mild and asymptomatic course of the new coronavirus infection (COVID-19) on the male sperm's parameters. Methods: The study included 397 patients who applied for a spermogram. All the patients underwent a spermogram study according to the WHO protocol, with the additionally measured degree of sperm DNA fragmentation, acrosine activity, fructose level, zinc level, citric acid level, neutral-glucosidase activity. A test for sperm binding to hyaluronic acid (HBA test) was performed, and the serum antibodies (IgM and IgG) against SARS-CoV-2 were analyzed. The study was conducted twice with an interval of 35 months. Results: At the first examination, normozoospermia was found in 33.5% (n=133) of patients, pathospermia in 66.5% (n=264). All the patients had no antibodies against SARS-CoV-2 (COVID-19). When the analysis was repeated after 35 months, antibodies (IgG) against SARS-CoV-2 were detected in 144 patients: in 14.6% (n=21) the coronavirus infection was mild, and in 85.4% (n=123) it was asymptomatic. Those patients who received some type of a treatment (andrologic, anticovid, and/or other) were excluded from the further study. The subsequent analysis of the data from the untreated patients (131 patients without antibodies against SARS-CoV-2 and 93 patients with antibodies (IgG) against SARS-CoV-2) was performed using the Student's paired test. For all the parameters of the standard spermogram according to the WHO protocol, the found changes after the mild and asymptomatic form of COVID-19 were not statistically significant. Also, the changes in the degree of fragmentation of sperm DNA, the enzymatic activity of acrosine, and other estimated parameters of the sperm (levels of fructose, citric acid, zinc, and the activity of neutral-glucosidase) were not statistically significant. The results of the test for the spermatozoa's interaction with hyaluronic acid (HBA test) worsened and had statistically significant differences after the coronavirus infection in both the mild form (p=0.006) and asymptomatic form (p=0.001). There were no statistically significant changes in the sperm parameters (including those from the HBA test) in the patients who had not had the new coronavirus infection. Conclusions: No statistically significant data were obtained on the effect of mild and asymptomatic forms of the course of the new coronavirus infection on the parameters of the standard spermogram, on the degree of fragmentation of spermatozoa's DNA and the enzymatic activity of acrosin. Mild and asymptomatic forms of the new coronavirus infection course can negatively affect the interaction of spermatozoa with hyaluronic acid (HBA test), that indicates the impairment of the spermatozoa binding to the zona pellucida. One should pay attention to the HBA test when examining the sperm of patients who have suffered the new coronavirus infection.

Direct, indirect, post-infection damages induced by coronavirus in the human body: an overview

Background

Severe acute respiratory syndrome Coronavirus-2 invades the cells via ACE2 receptor and damages multiple organs of the human body. Understanding the pathological manifestation is mandatory to endure the rising post-infection sequel reported in patients with or without comorbidities.

Materials and methods

Our descriptive review emphasises the direct, indirect and post-infection damages due to COVID-19. We have performed an electronic database search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with selective inclusion and exclusion criteria.

Results

The included studies substantiated the extensive damages in the multiple organs due to direct and indirect consequences of COVID-19. After an apparent recovery, the prolonged presentation of the symptoms manifests as post-COVID that can be related with persisting viral antigens and dysregulated immune response.

Conclusion

A few of the symptoms of respiratory, cardiovascular, and neuropsychiatric systems that persist or reappear as post-COVID manifestations. Vaccination and preventive programs will effectively reduce the prevalence but, the post-COVID, a multisystem manifestation, will be a significant tribulation to the medical profession. However, the issue can be managed by implementing public health programs, rehabilitation services, and telemedicine virtual supports to raise awareness and reduce panic.

The Possible Role of SARS-CoV-2 in Male Fertility: A Narrative Review

The spread of severe acute respiratory syndrome—Coronavirus 2 (SARS-CoV-2) around the world has rapidly sparked the interest of the scientific community to discover its implications in human health. Many studies have suggested that SARS-CoV-2 is directly or indirectly involved in the male reproductive tract impairment. Some evidence supports the possible role of the virus in male infertility. Therefore, this review aims to summarize the relationship between the male urogenital tract, male fertility, and the gonadal hormone profile. The testis is one of the organs with the highest expression of the angiotensin-converting enzyme (ACE) 2-receptor that allows the virus to penetrate human cells. Orchitis is a possible clinical manifestation of COVID-19 and testicular damage has been found on autopsy in the testes of patients who died from the disease. SARS-CoV-2 infection can compromise the blood-testis barrier, favoring testicular damage and the production of anti-sperm autoantibodies. Some studies have detected the presence of SARS-CoV-2 in semen and a high percentage of patients with COVID-19 have altered sperm parameters compared to controls. Finally, lower testosterone levels, higher luteinizing hormone (LH) levels, and decreased follicle-stimulating (FSH)/LH and testosterone/LH ratios suggest primary testicular damage. In conclusion, further studies are needed to evaluate the exact mechanisms by which SARS-CoV-2 affects the male reproductive system and fertility and to evaluate the reversibility of its long-term effects.

Non-Productive Infection of Glial Cells with SARS-CoV-2 in Hamster Organotypic Cerebellar Slice Cultures

The numerous neurological syndromes associated with COVID-19 implicate an effect of viral pathogenesis on neuronal function, yet reports of direct SARS-CoV-2 infection in the brain are conflicting. We used a well-established organotypic brain slice culture to determine the permissivity of hamster brain tissues to SARS-CoV-2 infection. We found levels of live virus waned after inoculation and observed no evidence of cell-to-cell spread, indicating that SARS-CoV-2 infection was non-productive. Nonetheless, we identified a small number of infected cells with glial phenotypes; however, no evidence of viral infection or replication was observed in neurons. Our data corroborate several clinical studies that have assessed patients with COVID-19 and their association with neurological involvement.

Mechanisms of SARS-CoV-2 and Male Infertility: Could Connexin and Pannexin Play a Role?

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on male infertility has lately received significant attention. SARS-CoV-2, the virus that causes coronavirus disease (COVID-19) in humans, has been shown to impose adverse effects on both the structural components and function of the testis, which potentially impact spermatogenesis. These adverse effects are partially explained by fever, systemic inflammation, oxidative stress, and an increased immune response leading to impaired blood-testis barrier. It has been well established that efficient cellular communication via gap junctions or functional channels is required for tissue homeostasis. Connexins and pannexins are two protein families that mediate autocrine and paracrine signaling between the cells and the extracellular environment. These channel-forming proteins have been shown to play a role in coordinating cellular communication in the testis and epididymis. Despite their role in maintaining a proper male reproductive milieu, their function is disrupted under pathological conditions. The involvement of these channels has been well documented in several physiological and pathological conditions and their designated function in infectious diseases. However, their role in COVID-19 and their meaningful contribution to male infertility remains to be elucidated. Therefore, this review highlights the multivariate pathophysiological mechanisms of SARS-CoV-2 involvement in male reproduction. It also aims to shed light on the role of connexin and pannexin channels in disease progression, emphasizing their unexplored role and regulation of SARS-CoV-2 pathophysiology. Finally, we hypothesize the possible involvement of connexins and pannexins in SARS-CoV-2 inducing male infertility to assist future research ideas targeting therapeutic approaches.

Infertility in Men: Advances towards a Comprehensive and Integrative Strategy for Precision Theranostics

Male infertility is an increasing and serious medical concern, though the mechanism remains poorly understood. Impaired male reproductive function affects approximately half of infertile couples worldwide. Multiple factors related to the environment, genetics, age, and comorbidities have been associated with impaired sperm function. Present-day clinicians rely primarily on standard semen analysis to diagnose male reproductive potential and develop treatment strategies. To address sperm quality assessment bias and enhance analysis accuracy, the World Health Organization (WHO) has recommended standardized sperm testing; however, conventional diagnostic and therapeutic options for male infertility, including physical examination and semen standard analysis, remain ineffective in relieving the associated social burden. Instead, assisted reproductive techniques are becoming the primary therapeutic approach. In the post-genomic era, multiomics technologies that deeply interrogate the genome, transcriptome, proteome, and/or the epigenome, even at single-cell level, besides the breakthroughs in robotic surgery, stem cell therapy, and big data, offer promises towards solving semen quality deterioration and male factor infertility. This review highlights the complex etiology of male infertility, especially the roles of lifestyle and environmental factors, and discusses advanced technologies/methodologies used in characterizing its pathophysiology. A comprehensive combination of these innovative approaches in a global and multi-centric setting and fulfilling the suitable ethical consent could ensure optimal reproductive and developmental outcomes. These combinatorial approaches should allow for the development of diagnostic markers, molecular stratification classes, and personalized treatment strategies. Since lifestyle choices and environmental factors influence male fertility, their integration in any comprehensive approach is required for safe, proactive, cost-effective, and noninvasive precision male infertility theranostics that are affordable, accessible, and facilitate couples realizing their procreation dream.

Corona and Reproduction, or Why the Corona Vaccination Does Not Result in Infertility

Background As the COVID-19 pandemic persists and new vaccines are developed, concerns among the general public are growing that both infection with the SARS-CoV-2 virus and vaccinations against the coronavirus (mRNA vaccines) could lead to infertility or higher miscarriage rates. These fears are voiced particularly often by young adults of reproductive age. This review summarizes the current data on the impact of SARS-CoV-2 infection and corona vaccinations on female and male fertility, based on both animal models and human data.

Method A systematic literature search (PubMed, Embase, Web of Science) was carried out using the search terms “COVID 19, SARS-CoV-2, fertility, semen, sperm, oocyte, male fertility, female fertility, infertility”. After the search, original articles published between October 2019 and October 2021 were selected and reviewed.

Results Despite the use of very high vaccine doses in animal models, no negative impacts on fertility, the course of pregnancy, or fetal development were detected. In humans, no SARS-CoV-2 RNA was found in the oocytes/follicular fluid of infected women; similarly, no differences with regard to pregnancy rates or percentages of healthy children were found between persons who had recovered from the disease, vaccinated persons, and controls. Vaccination also had no impact on live-birth rates after assisted reproductive treatment. No viral RNA was detected in the semen of the majority of infected or still infectious men; however, a significant deterioration of semen parameters was found during semen analysis, especially after severe viral disease. None of the studies found that corona vaccines had any impact on male fertility.

Discussion Neither the animal models nor the human data presented in recent studies provide any indications that fertility decreases after being vaccinated against coronavirus. However, there is a growing body of evidence that severe SARS-CoV-2 infection has a negative impact on male fertility and there is clear evidence of an increased risk of complications among pregnant women with SARS-CoV-2 infection. The counseling offered to young adults should therefore take their fears and concerns seriously as well as providing a structured discussion of the current data.

The polygamous GnRH neuron: Astrocytic and tanycytic communication with a neuroendocrine neuronal population

To ensure the survival of the species, hypothalamic neuroendocrine circuits controlling fertility, which converge onto neurons producing gonadotropin-releasing hormone (GnRH), must respond to fluctuating physiological conditions by undergoing rapid and reversible structural and functional changes. However, GnRH neurons do not act alone, but through reciprocal interactions with multiple hypothalamic cell populations, including several glial and endothelial cell types. For instance, it has long been known that in the hypothalamic median eminence, where GnRH axons terminate and release their neurohormone into the pituitary portal blood circulation, morphological plasticity displayed by distal processes of tanycytes modifies their relationship with adjacent neurons as well as the spatial properties of the neurohemal junction. These alterations not only regulate the capacity of GnRH neurons to release their neurohormone, but also the activation of discrete non-neuronal pathways that mediate feedback by peripheral hormones onto the hypothalamus. Additionally, a recent breakthrough has demonstrated that GnRH neurons themselves orchestrate the establishment of their neuroendocrine circuitry during postnatal development by recruiting an entourage of newborn astrocytes that escort them into adulthood and, via signalling through gliotransmitters such as prostaglandin E2, modulate their activity and GnRH release. Intriguingly, several environmental and behavioural toxins perturb these neuron-glia interactions and consequently, reproductive maturation and fertility. Deciphering the communication between GnRH neurons and other neural cell types constituting hypothalamic neuroendocrine circuits is thus critical both to understanding physiological processes such as puberty, oestrous cyclicity and aging, and to developing novel therapeutic strategies for dysfunctions of these processes, including the effects of endocrine disruptors.

Testosterone as a Biomarker of Adverse Clinical Outcomes in SARS-CoV-2 Pneumonia

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect testicles. Lower testosterone levels have been associated with worse clinical outcomes and higher mortality. Our objective was to evaluate the hypothalamic−pituitary−gonadal axis of men admitted with SARS-CoV-2 pneumonia and its link with the pneumonia-treatment intensification. Short-term changes in hormonal parameters were also assessed. Methods: Men admitted with SARS-CoV-2 pneumonia were recruited in two different hospitals in Piedmont, Italy. In all patients, the assessment of total testosterone (TT), calculated free testosterone (cFT), gonadotropins, inhibin B (InhB), and other biochemical evaluations were performed at admission (T0) and before discharge (T1). Through a review of medical records, clinical history was recorded, including data on pneumonia severity. Results: Thirty-five men (median age 64 [58−74] years) were recruited. Lower TT and cFT levels at T0 were associated with CPAP therapy (p = 0.045 and 0.028, respectively), even after adjusting for age and PaO2/FIO2 ratio in a multivariable analysis. In those discharged alive, lower TT and cFT levels were associated with longer hospital stay (p < 0.01). TT, cFT, and InhB were below the normal range at T0 and significantly increased at T1 (TT 1.98 [1.30−2.72] vs. 2.53 [1.28−3.37] ng/mL, p = 0.038; cFT (0.0441 [0.0256−0.0742] vs. 0.0702 [0.0314−0.0778] ng/mL, p = 0.046; InhB 60.75 [25.35−88.02] vs. 77.05 [51.15−134.50], p < 0.01). Conclusions: Both TT and cFT levels are associated with adverse clinical outcomes in men admitted with SARS-CoV-2 pneumonia. As TT, cFT and InhB levels increase before discharge, short-term functional recovery of steroidogenesis and an indirect improvement of spermatozoa functional status could be hypothesized.

COVID-19 and the Endocrine System: A Review of the Current Information and Misinformation

Coronavirus disease 2019 (COVID-19) infection primarily involves the respiratory system but has many noteworthy extra pulmonary manifestations as well. We write this review to highlight the basis of some pathophysiological mechanisms of COVID-19 infection-induced endocrine dysfunction. Different scientific databases and institutional websites were searched to collect and consolidate the most up-to-date data relating to COVID-19 infection and endocrine systems. Hypopituitarism, central diabetes insipidus, SIADH, thyroid abnormalities, hyperglycemia, adrenal insufficiency, orchitis and alteration in sperm morphology have been reported in case reports of patients with COVID-19 infection. Data focusing on COVID-19 vaccination was also searched to summarize the effect, if any, on the endocrine system. Endocrinopathies noted post COVID-19 vaccination, including cases of adrenal hemorrhage, new onset Type II Diabetes Mellitus and subacute thyroiditis, are also discussed in this review. This review calls attention to the misinformation relating to COVID-19 vaccination with supposed endocrine effects such as infertility and problems with pregnancy. Rebutting these misconceptions can help increase compliance and maximize COVID-19 vaccination to the public.

Effects and safety of COVID-19 vaccination on assisted reproductive technology and pregnancy: A comprehensive review and joint statements of the KSRM, the KSRI, and the KOSAR

Humanity is in the midst of the coronavirus disease 2019 (COVID-19) pandemic, and vaccines—including mRNA vaccines—have been developed at an unprecedented speed. It is necessary to develop guidelines for vaccination for people undergoing treatment with assisted reproductive technology (ART) and for pregnancy-related situations based on the extant laboratory and clinical data. COVID-19 vaccines do not appear to adversely affect gametes, embryos, or implantation; therefore, active vaccination is recommended for women or men who are preparing for ART. The use of intravenous immunoglobulin G (IVIG) for the treatment of immune-related infertility is unlikely to impact the effectiveness of the vaccines, so COVID-19 vaccines can be administered around ART cycles in which IVIG is scheduled. Pregnant women have been proven to be at risk of severe maternal and neonatal complications from COVID-19. It does not appear that COVID-19 vaccines harm pregnant women or fetuses; instead, they have been observed to deliver antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the fetus. Accordingly, it is recommended that pregnant women receive COVID-19 vaccination. There is no rationale for adverse effects, or clinical cases of adverse reactions, in mothers or neonates after COVID-19 vaccination in lactating women. Instead, antibodies to SARS-CoV-2 can be delivered through breast milk. Therefore, breastfeeding mothers should consider vaccination. In summary, active administration of COVID-19 vaccines will help ensure the safe implementation of ART, pregnancy, and breastfeeding.

The impact of the COVID-19 pandemic on women seeking fertility treatment: the patient’s perspective

Purpose

This study sought the views of women with impaired fertility on the impact of the COVID-19 pandemic on their fertility treatment and psychological wellbeing.

Methods

A cross-sectional, anonymous, online questionnaire was completed in June–December 2020 by 249 women attending fertility clinics across Germany. All women seeking treatment in fertility clinics were eligible to participate. The online survey covered questions about the patient’s quality of life, their opinions about the professional societies’ recommendations and their effects as well as any concerns about infection with SARS-CoV-2.

Results

Three-quarters of participants disagreed with the pausing of fertility treatments. Women who participated from October to December 2020, when the incidence rate was high, were as likely to disagree as participants that participated from June to September 2020 (73% vs 79%, p = 0.3). Seventy-two participants (29%) had their appointments cancelled. Nearly all (97%) reported being upset by this, with 40 (56%) reporting that they were extremely or very disappointed about the cancellation. Women who had to wait 10 weeks or longer were more likely to be upset by the postponement or cancellation of their appointment than women who had to wait a shorter amount of time (p = 0.01). Many participants (41%) were worried about possible negative effects a SARS-CoV-2 infection might have related to their fertility, pregnancy or unborn child.

Conclusion

Postponement of treatments increased distress among patients and should be avoided when possible. Fertility clinics must provide information about the current state of knowledge of SARS-CoV-2 infections in pregnancies and options for immunization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-021-06379-y.

Impact of COVID-19 on fertility and assisted reproductive technology (ART): a systematic review

The appearance of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a major obstacle for the performing of current medical activities throughout the world. COVID-19 has affected humanity in many ways, thus causing a great medical, social, economic, and political instability. The aim of this study was to make an analysis of the scientific data obtained by so far to highlight the impact that COVID-19 has had on fertility and assisted reproductive technology (ART). Infection with SARS-CoV-2 alters the normal immune response by local and systemic damage to tissues and organs. After the virus enters the body, the first lesions are produced in the respiratory tract. Extrapulmonary lesions specific to COVID-19 include acute renal lesions/acute kidney damage, hepatocellular lesions, neurological diseases, myocardial dysfunction and arrhythmia, gastrointestinal diseases but also genital impairment. The possible impairment of the male reproductive system is because angiotensin-converting enzyme 2 (ACE2) receptors are in an increased number in the testes, seminiferous duct cells, spermatogonia, Leydig cells and Sertoli cells. Many published studies to date have pointed out that COVID-19 could also affect female fertility and disrupt the functions of the female reproductive system. The theory that this virus can also be transmitted sexually and can cause infertility or testicular damage is supported by the fact that the virus can be isolated in the semen of COVID-19 patients but only during the disease. Choosing the best method of treating infertility during the COVID-19 pandemic is multifactorial, but the risk of infection and compliance with specific ART hygiene protocols must always be considered. Currently, there is no scientific basis regarding the fact that the COVID-19 vaccination would influence fertility.

[Impact of SARS-CoV-2 on fertility, gametes' quality and Assisted Reproduction Technology]

Le contexte actuel de pandémie conduit à s’interroger sur les conséquences de la COVID-19 en Assistance médicale à la procréation (AMP). En effet, suite aux premières recommandations de l’Agence de la biomédecine en mars 2020, les centres d’AMP ont suspendu leurs activités. La reprise progressive des tentatives en mai 2020 s’est accompagnée de nombreux questionnements, concernant les effets directs et indirects du SARS-CoV-2 sur la qualité des gamètes, la gamétogenèse, la fertilité, la grossesse et la santé néonatale. L’objectif de cette revue de la littérature est de synthétiser les données disponibles, pour informer les patient(e)s pris(es) en charge et adapter les pratiques d’AMP en cette période de la COVID-19. La plupart des études récentes se basent sur l’évaluation des effets du syndrome infectieux, sur l’analyse des facteurs hormonaux, et sur l’expression des protéines d’entrée virale (ACE2 et TMPRSS2) au niveau des cellules impliquées dans la gamétogenèse pour évaluer les répercussions de la COVID-19. La transmission materno-fœtale du SARS-CoV-2 n’a pas pu être démontrée à ce jour, mais l’infection néonatale reste possible. Néanmoins, les hommes seraient plus à risque d’être infectés par le SARS-CoV-2, d’être symptomatiques et la spermatogenèse est vraisemblablement affectée. La présence du virus dans le sperme est un évènement rare, mais l’ensemble de ces paramètres sont à prendre en compte dans la prise en charge des couples en AMP. Cependant, aucune conséquence sur la qualité des gamètes féminins n’a été mise en évidence jusqu’à présent.

Will Procreation Ever Be The Same After COVID-19?

Medically assisted procreation will never be the same again after this China Virus epidemic. With billions of lives being affected by this damaging global pandemic, medically assisted procreation services were not left unharmed with far-reaching consequences. New challenges are now emerging concerning COVID-19, such as associated reproductive implications and the consequences of assisted and natural procreation in the presence of acute SARS-CoV-2 infection and delayed consequences after patient recovery. There is a hypothesis that testicular damage and subsequent infertility may result following COVID-19 infection and the possibility of sexual transmission, as SARS-CoV-2 has been identified in the semen of infected patients. Vaccine hesitancy in young women planning pregnancies has been heightened because of the spread of misinformation on social media stating that COVID-19 vaccines will cause sterility in women. Reassuring data from accidental pregnancies that have occurred in the clinical trials of approved COVID-19 vaccines indicate that vaccination does not harm fertility or increase the rate of miscarriage. Scientists have quickly related to good tissue practices in vitro fertilization and a rethink is on about encouraging biopsies and focusing on safe vitrification protocols keeping in mind that ova, sperm, and embryos could be possible vectors for disease transmission with the limited research on the SARS-CoV-2 virus. Going ahead with segmented IVF without delay, freezing the generated embryos and pushing back the embryo transfer after the pandemic appears to be the best strategy at present. An international group of researchers have proposed a prognostic stratification of more vulnerable infertility cases in order to plan a progressive restart of worldwide fertility treatments.

Effects of Infection with SARS-CoV-2 on the Male and Female Reproductive Systems: A Review

Coronavirus Disease-2019 (COVID-19) is a rapidly spreading pandemic that began at the end of 2019. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Reproductive health has always been one of the most important healthcare problems, and the impacts of COVID-19 on the reproductive systems have become an emerging topic. The effects of infection with SARS-CoV-2 on males are more harmful than on females. The outcomes of pregnancy also can show the condition of male and female reproductive system health. The vertical transmission of SARS-CoV-2 significantly affects pregnancy healthy. SARS-CoV-2, antibody, and other factors, such as the decline of lymphocyte counts, and increased erythrocyte sedimentation rate, C-reactive protein, and D-dimer levels, are evidence of SARS-CoV-2 vertical transmission. Angiotensin-converting enzyme 2 (ACE2) is regarded as a virus receptor in the reproductive system. The expression and activity of ACE2 are influenced by sex hormones, especially the male sex hormones. The strength of immunity is crucial to fighting off viral infection. Antibodies against SARS-CoV-2 show different expression in male and female patients, and the antibodies have been regarded as having potential applications in COVID-19 prevention and treatment.

This review aims to present the current status of what is known about the involvement of the male and female reproductive systems, as well as the effects on pregnancy health, during infection with SARS-CoV-2, and discusses the implications for future fertility.

Reproductive Health in the Time of COVID

In spring 2020, the pandemic began shutting down the world-restaurants, colleges, even entire cities felt emptied and closed. A cloud of uncertainty lingered over most parts of the world and altered our daily schedules and tasks. But for a wide segment of society, it wasn't the toilet paper, or the masks, or the isolation from their families that hurt the worst-it was the sudden uncertainty around one of the most fundamental aspects of our lives: reproduction.