Impaired semen parameters in patients with confirmed SARS-CoV-2 infection: A prospective cohort study

Association between inactivated COVID-19 vaccine and semen quality among males recovered from omicron infection: a retrospective cohort study

BACKGROUND

The protective effects of inactivated COVID-19 vaccines against SARS-CoV-2-associated semen impairment remain underexplored. We investigated associations between BBIBP-CorV vaccination and the semen quality in males recovering from SARS-CoV-2 infection.

RESEARCH DESIGN AND METHODS

This single-center retrospective cohort study included 1,496 males recovering from SARS-CoV-2 infection at a tertiary hospital in Urumqi, China (February-May 2023). Participants were categorized into long-term and short-term effects groups based on the interval between semen collection and their most recent SARS-CoV-2 infection. The study assessed the association between the different doses of BBIBP-CorV vaccination and semen quality in both groups.

RESULTS

A total of 1496 participants were recruited for the short-term (n = 307) and long-term effect groups (n = 1189). Participants had a median age of 32 (IQR: 30, 35). Compared to unvaccinated controls, 2-dose and 3-dose recipients showed reduced short-term semen quality impairment risks, with adjusted RR of 0.945 (95% CI 0.918, 0.973) and 0.965 (95% CI 0.937, 0.993), respectively. No significant results were found for long-term effect groups.

CONCLUSION

Inactivated COVID-19 vaccination may protect against semen quality impairment among males recovering from SARS-CoV-2 Omicron infection within 90 days, especially in terms of semen volume and sperm progressive motility.

Alterations in Semen Quality and Immune-Related Factors in Men with Infertility who Recovered from COVID-19

The emergence of coronavirus disease 2019 (COVID-19) has triggered research into its impact on male reproductive health. However, studies exploring the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on semen quality in infertile men remain limited. Herein, we enrolled 781 male infertile patients who recovered from COVID-19 and analyzed their semen and blood samples collected at different time points. We found that SARS-CoV-2 RNA was undetectable in semen samples. Compared with pre-COVID-19 status, total sperm count, sperm concentration, vitality, motility, and percentage of sperm cells with normal morphology decreased significantly in the first month post-COVID-19. However, these alterations were reversed in the third month. Furthermore, seminal plasma samples exhibited reduced proinflammatory cytokine levels and notable changes in amino acid, nucleic acid, and carbohydrate metabolism by the third month compared with those in the first month. By contrast, no significant alterations in reproductive hormone levels were found. Vitality, progressive motility, and total motility negatively correlated with body temperature when it was above 38°C. In conclusion, semen quality initially decreases post-COVID-19 but reverses after approximately 3 months, with a decline related to inflammatory and fever. These findings may provide guidance to infertile male patients who need assisted reproductive technology.

COVID-19 infection was associated with poor sperm quality: a cross-sectional and longitudinal clinical observation study

To ascertain whether COVID-19 infection affects sperm quality and measure the scale of the effects. A cross sectional study and a longitudinal study were conducted during the SARS-CoV-2 pandemic (from September 7th 2022 to late January 2023) in China. 604 patients participated in the cross sectional study; 140 in the longitudinal study with 149 unaffected natural controls. The cross sectional study included participants who produce semen sample after COVID-19. The longitudinal study included COVID-19 positive participants who could provide semen samples before and after the infection. In addition, patients unaffected by the infection who could provide two consecutive semen samples over the same period were included as controls for the longitudinal study. Conventional sperm quality parameters including sperm count, motility, morphology and more recent parameters such as sperm DNA fragmentation index (DFI) and sperm chromatin immaturity were observed. In the cross sectional study, the exposure group demonstrated significantly lower total sperm count (159.58 × 106 vs. 185.42 × 106, P = 0.042), lower percentage of grade A sperms (5.37% vs. 8.45%, P = 0.009), lower progressive motility (24.74 ± 14.96% vs. 28.73 ± 16.65%, P = 0.023), lower total motility (32.04 ± 18.03% vs. 36.91 ± 20.86%, P = 0.022), and higher sperm DFI (17.50% vs. 11.75%, P = 0.030) than the controls. In the longitudinal study, after the infection, patients showed lower total sperm count (131.80 × 106 vs. 173.63 × 106, Δd = -20.49 × 106, P = 0.018 ), lower percentage of grade A sperms ( 2.61% vs. 8.50%, Δd = -3.18%, P < 0.001), lower progressive motility (19.82 ± 13.68% vs. 24.88 ± 14.97%, Δd = -5.07 ± 11.94%, P < 0.001) and lower total motility (26.64 ± 17.35% vs. 32.25 ± 18.69%, Δd = -5.62 ± 14.30%, P < 0.001) and higher DFI (32.10 ± 21.30% vs. 26.49 ± 18.54%, Δd = 5.61 ± 13.71%, P < 0.039) than before the infection, while the negative controls showed the opposite changes. Finally, in the longitudinal study, after the infection, 59.29% of the COVID-19 positive patients showed deteriorated sperm concentration, 57.86% deteriorated total sperm count, 71.43% Grade A sperm, 65.00% progressive motility, 69.29% total motility, and 75.00% sperm DFI, while the changes in negative controls were all less than 40% (P < 0.002). COVID-19 was associated with poor sperm quality. The findings would be useful for clinicians to manage men with fertility problems who suffered COVID-19.

Reversible effects of the SARS-CoV-2 on semen parameters

Despite that the SARS-CoV-2 pandemic has been controlled, it has affected a large proportion of the population, raising some concerns about potential sequelae in men at reproductive age. To contribute to the clarification of this issue, we performed a retrospective study comparing semen parameters values before and after confirmed SARS-CoV-2 infection in a large cohort of infertile men, compared to a control group that did not undergo SARS-CoV-2 infection. Wilcoxon test on paired samples and general linear regression model showed that SARS-CoV-2 infection has a detrimental effect on semen volume values (p < 0.005). However, semen volume seems to be significantly lower only during the first spermatogenic cycle after SARS-COV-2 infection (p < 0.005) and mainly in unvaccinated patients (p < 0.05). In addition, we detected alterations in progressive motility in patients infected with the alpha SARS-COV-2 strain (p < 0.05). In conclusion, our results show that although SARS-CoV-2 has a small effect on semen volume and sperm motility in infertile men, depending on the infectious strain or vaccination status, pre-infection values of semen parameters appear to be restored over one spermatogenic cycle after infection.

J. A, T. M. A, Akhigbe RE. SARS-CoV-2 impairs male fertility by targeting semen quality and testosterone level: A systematic review and meta-analysis

BACKGROUND

Since the discovery of COVID-19 in December 2019, the novel virus has spread globally causing significant medical and socio-economic burden. Although the pandemic has been curtailed, the virus and its attendant complication live on. A major global concern is its adverse impact on male fertility.

AIM

This study was aimed to give an up to date and robust data regarding the effect of COVID-19 on semen variables and male reproductive hormones.

MATERIALS AND METHODS

Literature search was performed according to the recommendations of PRISMA. Out of the 852 studies collected, only 40 were eligible for inclusion in assessing the effect SARS-CoV-2 exerts on semen quality and androgens. More so, a SWOT analysis was conducted.

RESULTS

The present study demonstrated that SARS-CoV-2 significantly reduced ejaculate volume, sperm count, concentration, viability, normal morphology, and total and progressive motility. Furthermore, SARS-CoV-2 led to a reduction in circulating testosterone level, but a rise in oestrogen, prolactin, and luteinizing hormone levels. These findings were associated with a decline in testosterone/luteinizing hormone ratio.

CONCLUSIONS

The current study provides compelling evidence that SARS-CoV-2 may lower male fertility by reducing semen quality through a hormone-dependent mechanism; reduction in testosterone level and increase in oestrogen and prolactin levels.

Impact of COVID-19 on testicular function: a systematic review and meta-analysis

INTRODUCTION

Studies investigating the effects of SARS-CoV-2 on male reproductive function are few and heterogeneous, and results are often conflicting. This systematic review and meta-analysis was carried out on studies conducted in men with active or anamnestic SARS-CoV-2 infection to evaluate its consequences on the male sex hormone profile and semen parameters.

MATERIALS AND METHOD

This meta-analysis follows the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocols. PubMed, Scopus, Cochrane, and Embase databases were searched to identify relevant studies. We originally selected 3553 articles. After the eligibility phase, 16 articles met our inclusion criteria encompassing 11 case-control studies and 5 cohort studies (2 prospective and 3 retrospective studies). We performed the quantitative analysis with Comprehensive Meta-Analysis Software. Cochran-Q and heterogeneity (I2) indexes were used to assess statistical heterogeneity. Sensitivity analysis and publication bias tests were also performed.

RESULTS

Overall, 1250 patients with active or recent (up to 80 days before) COVID-19 infection and 1232 matched healthy controls were included. Sperm concentration, total sperm count, and total motility were significantly lower in patients compared with controls. Patients also showed lower levels of total testosterone and follicle-stimulating hormone, and higher levels of luteinizing hormone, 17β-estradiol, and prolactin compared with healthy controls. None of the included studies found the presence of SARS-CoV-2 mRNA in the semen of infected patients.

CONCLUSION

The present systematic review and meta-analysis suggests the presence of an association between SARS-CoV-2 infection and primary testicular damage manifested with a picture of altered steroidogenesis and worsening spermatogenesis. The absence of the virus in the seminal fluid indicates a low possibility of sexual transmission of the infection to partners and offspring. However, our findings mostly show short-term follow-up, while few studies have considered the long-term consequences of the viral infection, thus further studies are needed to evaluate the long-term consequences on male reproductive health.

COVID-19 and male fertility: short- and long-term impacts of asymptomatic vs. symptomatic infection on male reproductive potential

Background

Studies exploring the effect of COVID-19 on male reproductive system suggest a detrimental association, however with conflicting results. The aim of this study was to assess the association between COVID-19 infection and male reproductive potential including hormone profiles and semen parameters.

Methods

This prospective cohort study included 48 patients with confirmed COVID-19 infection. Patients were subdivided into an asymptomatic group (n = 30) and a group with COVID-19 symptoms (n = 18). Serum hormone levels including testosterone, LH, FSH and estradiol were collected during active infection (baseline, time 0), and at 3 and 6 months following COVID-19 infection. Semen samples (basic semen analysis and oxidation reduction potential) were examined at 3 and 6 months following infection. Student and paired-t tests were used to compare continuous variables between the study groups and across the studied time intervals, respectively. Multivariate binary logistic regression analysis was performed to explore predictors for COVID-19 symptoms during active infection.

Results

Patients with COVID-19 symptoms were significantly older (p = 0.02) and had significantly lower serum testosterone levels (p = 0.01) and significantly higher LH: testosterone ratio (p = 0.01) than asymptomatic patients. Multivariate analysis revealed older age (OR =  1.18, p = 0.03) and lower serum testosterone level (OR = 0.8, p = 0.03) as independent predictors of symptomatic COVID-19 infection. Significant increase in testosterone (p < 0.001 for both) and decrease in LH (p = 0.02, p = 0.007) and LH: testosterone (p = 0.02, p = 0.005) levels were observed at 3 and 6 months in patients with COVID-19 symptoms. Asymptomatic patients demonstrated significant increase in testosterone (p = 0.02) and decrease in LH: testosterone (p = 0.04) levels only at 3 months following COVID-19 infection. No significant differences were observed between the two study groups with regards to the semen analysis results obtained at 3 or 6 months following COVID-19 infection.

Conclusion

Significantly lower testosterone values are associated with worse disease severity among men with COVID-19 infection. This association appears to be temporary as a significant increase in testosterone levels are witnessed as early as 3 months following recovery. No significant detrimental effect for COVID-19 infection on testicular sperm production is found in this patient population.

Effect of SARS-CoV-2 infection on semen parameters in sperm bank volunteers with normal sperm concentration

In this study, we aimed to assess the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on semen parameters. The study comprised 110 sperm volunteers who self-reported SARS-CoV-2 infection from the Human Sperm Bank of the Center for Reproductive Medicine, Shandong University (Jinan, China). The volunteers had normal sperm concentration before infection. Each volunteer provided semen samples before and after infection. We selected 90 days after infection as the cutoff point. Semen parameters within 90 days after infection of 109 volunteers (group A) were compared with semen parameters before infection. Moreover, semen parameters on or after 90 days after infection of 36 volunteers (group B) were compared with semen parameters before infection. Furthermore, based on whether the volunteers had completed the three-dose SARS-CoV-2 vaccination booster, volunteers in group A and B were further divided into two subgroups separately. Semen parameters were compared before and after infection in each subgroup. Our results showed that in this cohort population, the semen quality in volunteers with normal sperm concentrations before infection decreased after SARS-CoV-2 infection within 90 days, while the semen quality returned to preinfection levels after 90 days. The completion of a three-dose SARS-CoV-2 vaccination booster may exert a protective effect on semen quality after infection.

Systematic analyses of the factors influencing sperm quality in patients with SARS-CoV-2 infection

To figure out how does SARS-CoV-2 affect sperm parameters and what influencing factors affect the recovery of sperm quality after infection? We conducted a prospective cohort study and initially included 122 men with SARS-CoV-2 infection. The longest time to track semen quality after infection is 112 days and 58 eligible patients were included in our study eventually. We subsequently exploited a linear mixed-effects model to statistically analyze their semen parameters at different time points before and after SARS-CoV-2 infection. Semen parameters were significantly reduced after SARS-CoV-2 infection, including total sperm count (211 [147; 347] to 167 [65.0; 258], P < 0.001), sperm concentration (69.0 [38.8; 97.0] to 51.0 [25.5; 71.5], P < 0.001), total sperm motility (57.5 [52.3; 65.0] to 51.0 [38.5; 56.8], P < 0.001), progressive motility (50.0 [46.2; 58.0] to 45.0 [31.5; 52.8], P < 0.001). The parameters displayed the greatest diminution within 30 days after SARS-CoV-2 infection, gradually recovered thereafter, and exhibited no significant difference after 90 days compared with prior to COVID-19 infection. In addition, the patients in the group with a low-grade fever showed a declining tendency in semen parameters, but not to a significant degree, whereas those men with a moderate or high fever produced a significant drop in the same parameters. Semen parameters were significantly reduced after SARS-CoV-2 infection, and fever severity during SARS-CoV-2 infection may constitute the main influencing factor in reducing semen parameters in patients after recovery, but the effect is reversible and the semen parameters gradually return to normal with the realization of a new spermatogenic cycle.

Update on known and emergent viruses affecting human male genital tract and fertility

Many viruses infect the male genital tract with harmful consequences at individual and population levels. In fact, viral infections may induce damage to different organs of the male genital tract (MGT), therefore compromising male fertility. The oxidative stress, induced during viral-mediated local and systemic inflammation, is responsible for testicular damage, compromising germinal and endocrine cell functions. A reduction in sperm count, motility, number of normal sperm and an increase in DNA fragmentation are all common findings in the course of viral infections that, however, generally regress after infection clearance. In some cases, however, viral shedding persists for a long time leading to unexpected sexual transmission, even after the disappearance of the viral load from the blood.The recent outbreak of Zika and Ebola Virus evidenced how the MGT could represent a reservoir of dangerous emergent viruses and how new modalities of surveillance of survivors are strongly needed to limit viral transmission among the general population.Here we reviewed the evidence concerning the presence of relevant viruses, including emergent and re-emergent, on the male genital tract, their route of entry, their adverse effects on male fertility and the pattern of viral shedding in the semen.We also described laboratory strategies to reduce the risk of horizontal or vertical cross-infection in serodiscordant couples undergoing assisted reproductive technologies.

The impact of acute SARS-CoV-2 on testicular function including insulin-like factor 3 (INSL3) in men with mild COVID-19: A longitudinal study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect the male reproductive system as it uses angiotensin-converting enzyme (ACE)2, which is expressed in testicular tissue, as an entry point into the cell. Few studies have evaluated the long-term effects of mild coronavirus disease 2019 (COVID-19) on testicular function, and insulin-like factor 3 (INSL3) levels have not previously been assessed during acute SARS-CoV-2 infection.

OBJECTIVES

The aim of the study was to assess the impact of acute SARS-CoV-2 infection on testicular function including INSL3 and the presence of SARS-CoV-2 RNA in semen in non-hospitalised men with mild COVID-19.

MATERIALS AND METHODS

This longitudinal study included 36 non-hospitalised SARS-CoV-2-positive men (median age 29 years). Inclusion was within seven days following a positive SARS-CoV-2 reverse-transcription polymerase chain reaction test. Reproductive hormone levels, semen parameters, and the presence of SARS-CoV-2 RNA in oropharyngeal and semen samples were assessed during acute SARS-CoV-2 infection (baseline) and at three- and six-month follow-up. Wilcoxon matched-pair signed-rank (two samples) test was used to assess time-related alterations in reproductive hormone levels and semen parameters.

RESULTS

Lower plasma testosterone (T) (total and calculated free (c-fT)) and higher luteinising hormone (LH) concentrations were observed during acute SARS-CoV-2 infection (baseline) compared to three- and six-month follow-up. Consequently, ratios of c-fT/LH were lower at baseline compared to three- and six-month follow-up (p < 0.001 and p = 0.003, respectively). Concomitantly, lower INSL3 concentrations were observed at baseline compared to three-month follow-up (p = 0.01). The total number of motile spermatozoa was also lower at baseline compared to six-month follow-up (p = 0.02). The alterations were detected irrespective of whether the men had experienced SARS-CoV-2-related fever episodes or not. No SARS-CoV-2 RNA was detected in semen at any time point.

DISCUSSION AND CONCLUSION

This study showed a reduction in testicular function, which was for the first time confirmed by INSL3, in men mildly affected by SARS-CoV-2 infection. The risk of transmission of SARS-CoV-2 RNA via semen seems to be low. Febrile episodes may impact testicular function, but a direct effect of SARS-CoV-2 cannot be excluded.

Does COVID-19 affect sperm quality in males? the answer may be yes, but only temporarily

BACKGROUND

The Corona Virus Disease 2019 (COVID-19) pandemic has raised concerns regarding its potential impact on male reproductive health. However, the impact of COVID-19 on sperm quality remains uncertain. This retrospective study aimed to investigate the short-term and relatively long-term effects of COVID-19 infection on sperm quality.

METHODS

A total of 85 males with fertility requirements, who underwent semen evaluation at Guilin People's Hospital between June 2022 and July 2023, were included in the study. Changes in semen parameters were analyzed across three specific timeframes: within 6 months before COVID-19 infection, within 3 months after COVID-19 infection, and 3-6 months after COVID-19 recovery.

RESULTS

The results revealed that the sperm concentration and total sperm number were significantly lower after infection compared to before, while in the recovery period, the sperm concentration, total sperm count, progressive motility, and normal morphology significantly increased. Comparing the three periods, the most significant difference was observed in sperm concentration, which exhibited a significant decrease after infection but returned to normal levels after recovery from COVID-19.

CONCLUSIONS

These findings suggest that COVID-19 may exert some impact on sperm quality, particularly evidenced by decreased sperm concentration post-infection. Fortunately, these effects on semen parameters appear to be temporary, with gradual restoration of semen parameters within 3-6 months after recovery. However, further research is needed to explore the underlying mechanisms and long-term implications of these observed changes in semen parameters.

Impact of COVID-19 disease on the male factor in reproductive medicine - how-to advise couples undergoing IVF/ICSI

CONTEXT

The COVID-19 pandemic has caused widespread concern about its potential impact on various aspects of human health.

AIMS

This narrative review aims to summarise the current knowledge about the impact of COVID-19 on sperm quality and its effect on assisted reproductive technology.

METHODS

In this narrative review, a literature search using the PubMed and MEDLINE databases was conducted to identify relevant original research articles published up to 29 January 2023.

RESULTS

Thirty original studies were included in our review. There is evidence that SARS-CoV-2 is detectable in seminal fluid during the acute phase of infection and for up to 1month. However, the fact that SARS-CoV-2 is barely detectable in semen makes sexual transmission very unlikely. COVID-19 infection has been associated with the following changes in sperm quality: morphology, altered motility, changed DNA fragmentation-index (DFI), decreased sperm concentration, lower total number of sperm, and a significant increase in leukocytes and cytokines. The effects mostly seem to be reversible and have not been shown to negatively affect the outcome of assisted reproductive technology but should lead to further research concerning the health of the offspring, because a correlation of increased DFI after COVID-19 even 5months after disease could be assumed.

CONCLUSIONS

The findings of this narrative review suggest that SARS-CoV-2 may harm sperm quality in the acute phase.

IMPLICATIONS

A recovery time of at least 3months regarding assisted reproductive therapy could be reasonable.

SARS-CoV-2 replicates in the human testis with slow kinetics and has no major deleterious effects ex vivo

IMPORTANCE

SARS-CoV-2 is a new virus responsible for the Covid-19 pandemic. Although SARS-CoV-2 primarily affects the lungs, other organs are infected. Alterations of testosteronemia and spermatozoa motility in infected men have raised questions about testicular infection, along with high level in the testis of ACE2, the main receptor used by SARS-CoV-2 to enter host cells. Using an organotypic culture of human testis, we found that SARS-CoV-2 replicated with slow kinetics in the testis. The virus first targeted testosterone-producing Leydig cells and then germ-cell nursing Sertoli cells. After a peak followed by the upregulation of antiviral effectors, viral replication in the testis decreased and did not induce any major damage to the tissue. Altogether, our data show that SARS-CoV-2 replicates in the human testis to a limited extent and suggest that testicular damages in infected patients are more likely to result from systemic infection and inflammation than from viral replication in the testis.

Persistent oligonecrozoospermia after asymptomatic SARS-CoV-2 infection. A case report and literature review

COVID-19 is known to have deleterious effects on different systems such as the respiratory, cardiovascular, central nervous, and gastrointestinal. However, conflicting data about the possible implications for male reproductive health and fertility have been reported. In addition, the long-term consequences of SARS-CoV-2 infection remain unclear. Herein, we report a case of a 42-year-old man with no known co-morbidities and normal baseline semen quality, who subsequently suffered an asymptomatic SARS-CoV-2 infection. Shortly after, the patient developed sudden oligoasthenozoospermia, even reaching azoospermia, which gradually evolved into persistent severe oligonecrozoospermia, accompanied by semen inflammation and oxidative stress. Remarkably, the latter occurred in the absence of urogenital infections, hormonal imbalances, tissue/organ obstruction/damage, medication or drug treatment, smoking, or exposure to toxins/pollutants, radiation, or high temperature. This case constitutes valuable clinical evidence that adds to the current knowledge in the field and highlights the need for further and longer follow-up studies to better understand the putative long-term consequences of SARS-CoV-2 infection on male fertility.

Comparison of semen parameters in the same patients before and after diagnosis of COVID-19

Clinical and histopathological evidence suggest that the male reproductive system may be negatively impacted in patients with coronavirus disease (COVID-19). The objective of this study is to investigate the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on semen parameters by comparing semen analyses before and after COVID-19 diagnosis in the same patient. We retrospectively analyzed 342 semen analyses by reviewing medical records. The study included two groups of patients: (i) those who underwent two consecutive semen analyses within 6 months, one before (n = 114) and one after (n = 114) COVID-19 diagnosis, and (ii) a control group (n = 114) that was age-matched and did not receive a diagnosis of COVID-19. The study results indicated a significant decrease in semen volume, total sperm count per ejaculate, progressive motile sperm count, total motile sperm count, and normal sperm morphology after SARS-CoV-2 infection in comparison to their respective values before the infection. Subgroup analyses showed that the duration of COVID-19 diagnosis (short-term vs. long-term) did not impact the changes in semen parameters. However, fever during the COVID-19 process had a negative effect on semen parameters, particularly sperm concentration, unlike in patients without fever. In conclusion, our findings suggest that SARS-CoV-2 infection is associated with a decline in semen quality, which may potentially impact male fertility. Furthermore, it's important to note that the negative effects on semen parameters may persist in the long-term. Our results also indicate that fever during active infection could be a significant risk factor that negatively affects spermatogenesis.

COVID-19 and Male Infertility: Is There a Role for Antioxidants?

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), jeopardizes male fertility because of the vulnerability of the male reproductive system, especially the testes. This study evaluates the effects of the virus on testicular function and examines the potential role of antioxidants in mitigating the damage caused by oxidative stress (OS). A comprehensive PubMed search examined exocrine and endocrine testicular function alteration, the interplay between OS and COVID-19-induced defects, and the potential benefit of antioxidants. Although the virus is rarely directly detectable in sperm and testicular tissue, semen quality and hormonal balance are affected in patients, with some changes persisting throughout a spermatogenesis cycle. Testicular pathology in deceased patients shows defects in spermatogenesis, vascular changes, and inflammation. Acute primary hypogonadism is observed mainly in severely infected cases. Elevated OS and sperm DNA fragmentation markers suggest redox imbalance as a possible mechanism behind the fertility changes. COVID-19 vaccines appear to be safe for male fertility, but the efficacy of antioxidants to improve sperm quality after infection remains unproven due to limited research. Given the limited and inconclusive evidence, careful evaluation of men recovering from COVID-19 seeking fertility improvement is strongly recommended.

COVID-19 associates with semen inflammation and sperm quality impairment that reverses in the short term after disease recovery

Introduction: COVID-19 exerts deleterious effects on the respiratory, cardiovascular, gastrointestinal, and central nervous systems, causing more severe disease in men than in women. However, cumulative reported data about the putative consequences on the male reproductive tract and fertility are controversial. Furthermore, the long-term effects of SARS-CoV-2 infection are still uncertain. Methods: In this study, we prospectively evaluated levels of inflammatory cytokines and leukocytes in semen and sperm quality parameters in a cohort of 231 reproductive-aged male patients, unvaccinated, who had recovered from mild or severe COVID-19 and in 62 healthy control individuals. Sperm quality was assessed early (less than 3 months) and long (more than 3 and up to 6 months) after having COVID-19. Interestingly, and unlike most reported studies, available extensive background and baseline data on patients' sperm quality allowed performing a more accurate analysis of COVID-19 effects on sperm quality. Results: Significantly higher levels of IL-1β, TNF and IFNγ were detected in semen from patients recently recovered from mild and/or severe COVID-19 with respect to control individuals indicating semen inflammation. Moreover, patients recovered from mild and/or severe COVID-19 showed significantly reduced semen volume, lower total sperm counts, and impaired sperm motility and viability. Interestingly, all observed alterations returned to baseline values after 3 or more months after disease recovery. Discussion: These results indicate that COVID-19 associates with semen inflammation and impaired semen quality early after disease. However, long COVID-19 seems not to include long-term detrimental consequences on male fertility potential since the observed alterations were reversible after 1-2 spermatogenesis cycles. These data constitute compelling evidence allowing a better understanding of COVID-19 associated sequelae, fundamental for semen collection in assisted reproduction.

Effect of COVID-19 on sperm parameters: pathologic alterations and underlying mechanisms

The rapid outbreak of the coronavirus disease 2019 (COVID-19) pandemic has brought challenges to different medical fields, especially reproductive health. To date, most studies on the effects of COVID-19 on male reproduction have some limitations. In addition, there is little research on the mechanisms underlying by which severe acute respiratory syndrome coronavirus 2 infection affects semen quality. Here, we revealed the possible impact of COVID-19 on sperm parameters and the potential mechanisms. At present, it is still controversial whether COVID-19-induced fever adversely affects sperm parameters. Severe acute respiratory syndrome coronavirus 2 can induce up-regulation of pro-inflammatory cytokine, which leads to the destruction of blood-testis barrier and impairment of spermatogenesis. Moreover, severe viral infection of the respiratory system could induce systemic oxidative stress. Sperm are highly vulnerable to it due to their limited levels of antioxidant defense, unsophisticated DNA damage detection and repair mechanisms. Our review prompt medical staff and patients to consciously check the reproductive function of COVID-19 male patients. Moreover, opening our prospective beyond the direct infection could be the key to better understand the COVID-19 short and long-term effects and provide a new idea for future treatment of patients with reproductive function injury.

SARS-CoV-2, fertility and assisted reproduction

BACKGROUND

In 2020, SARS-CoV-2 and the COVID-19 pandemic had a huge impact on the access to and provision of ART treatments. Gradually, knowledge of the virus and its transmission has become available, allowing ART activities to resume. Still, questions on the impact of the virus on human gametes and fertility remain.

OBJECTIVE AND RATIONALE

This article summarizes published data, aiming to clarify the impact of SARS-CoV-2 and the COVID-19 disease on human fertility and assisted reproduction, as well as the impact of vaccination, and from this, provide answers to questions that are relevant for people contemplating pregnancy and for health care professionals.

SEARCH METHODS

PUBMED/MEDLINE and the WHO COVID-19 database were searched from inception to 5 October 2022 with search terms focusing on 'SARS-CoV-2' and gametes, embryos, reproductive function, fertility and ART. Non-English studies and papers published prior to 2020 were excluded, as well as reviews and non-peer reviewed publications. Full papers were assessed for relevance and quality, where feasible.

OUTCOMES

From the 148 papers included, the following observations were made. The SARS-CoV-2-binding proteins, angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2), are expressed in the testis, but co-expression remains to be proven. There is some evidence of SARS-CoV-2 RNA in the ejaculate of COVID-19 patients with severe disease, but not in those with mild/moderate disease. SARS-CoV-2 infection can impair spermatogenesis, but this seems to resolve after one spermatogenic cycle. Testosterone levels seem to be lower during and after COVID-19, but long-term data are lacking; disease severity may be associated with testosterone levels. COVID-19 cannot be considered a sexually transmitted disease. There is no co-expression of ACE2 and TMPRSS2 in the myometrium, uterus, ovaries or fallopian tubes. Oocytes seem to have the receptors and protease machinery to be susceptible to SARS-CoV-2 infection; however, viral RNA in oocytes has not been detected so far. Women contemplating pregnancy following COVID-19 may benefit from screening for thyroid dysfunction. There is a possible (transient) impact of COVID-19 on menstrual patterns. Embryos, and particularly late blastocysts, seem to have the machinery to be susceptible to SARS-CoV-2 infection. Most studies have not reported a significant impact of COVID-19 on ovarian reserve, ovarian function or follicular fluid parameters. Previous asymptomatic or mild SARS-CoV-2 infection in females does not seem to negatively affect laboratory and clinical outcomes of ART. There are no data on the minimum required interval, if any, between COVID-19 recovery and ART. There is no evidence of a negative effect of SARS-CoV-2 vaccination on semen parameters or spermatogenesis, ovarian function, ovarian reserve or folliculogenesis. A transient effect on the menstrual cycle has been documented. Despite concerns, cross reactivity between anti-SARS-CoV-2 spike protein antibodies and Syncytin-1, an essential protein in human implantation, is absent. There is no influence of mRNA SARS-CoV-2 vaccine on patients' performance during their immediate subsequent ART cycle. Pregnancy rates post-vaccination are similar to those in unvaccinated patients.

WIDER IMPLICATIONS

This review highlights existing knowledge on the impact of SARS-CoV-2 infection or COVID-19 on fertility and assisted reproduction, but also identifies gaps and offers suggestions for future research. The knowledge presented should help to provide evidence-based advice for practitioners and couples contemplating pregnancy alike, facilitating informed decision-making in an environment of significant emotional turmoil.

SARS-CoV-2 Infection and the Male Reproductive System: A Brief Review

Many studies have suggested that SARS-CoV-2, directly or indirectly, can affect the male reproductive system, although the underlined mechanisms have not been completely elucidated yet. The purpose of this review is to provide a summary of the current data concerning the impact of SARS-CoV-2 infection on the male urogenital tract, with a particular emphasis on the testes and male fertility. The main data regarding the morphological alterations in the testes emerged from autoptic studies that revealed interstitial congestion, micro thrombosis, reduction of Sertoli, Leydig, and germinal cells, infiltrated immune cells, and atrophic seminiferous tubules consistent with orchitis. Furthermore, men with severe infection exhibit sperm parameter alterations, together with abnormalities of the hypothalamic-pituitary-testis axis, strongly suggesting that SARS-CoV-2 could increase the risk of male infertility. However, despite the inadequate number of longitudinal studies, spermatogenesis and sex hormone imbalance seem to improve after infection resolution. The yet unresolved question is whether the virus acts in a direct or/and indirect manner, as discordant data related to its presence in the testis and semen have been reported. Regardless of the direct effect, it has been postulated that the cytokine storm and the related local and systemic inflammation could strongly contribute to the onset of testis dysfunction, leading to male infertility. Therefore, multicentric and longitudinal studies involving a large number of patients are needed to understand the real impact of SARS-CoV-2 infection on male reproduction.

Does SARS-CoV-2 Affect Human Semen? A Systematic Review and Meta-Analysis

Contradictory results have been reported regarding effects of the SARS-CoV-2 upon human semen. A timely and up-to-date systematic review with meta-analysis appears necessary. This study aimed to deliver pooled prevalence (PP) of SARS-CoV-2 in semen and pooled semen parameters as compared with the uninfected. The relevant databases were scanned by two authors for observational studies reporting analysis of semen in COVID-19 patients. The SARS-CoV-2-infected were assigned to group A (exposed arm), whereas the uninfected to group B (unexposed arm). Newcastle-Ottawa Scale was used to address the risk of bias. PRISMA guidelines were adopted. In case of homogenous studies, fixed-effects model was followed, whereas for heterogenous studies random-effects model was used. Of 990 studies, 24 were eligible involving 1589 subjects (947 in group A and 642 in group B). The "comparability" domain was biased the most. SARS-CoV-2 RNA was detected in three studies among 8 individuals producing the PP of 1.76% (95% CI 0.72-3.21). Sperm concentration was reduced significantly (WMD = -16.23 [95% CI -25.56 to -6.89], as well as total sperm in ejaculate (WMD = -34.84 [95% CI - 43.51 to -26.17]) and sperm volume (WMD =  - 0.48 [95% CI - 0.59 to - 0.36] in group A as compared with controls. There was a non-significant effect upon progressive motility and leukocyte presence in semen. SARS-CoV-2 RNA in semen among the infected individuals is detected infrequently. By this token, sexual transmission through semen is of low probability and little concern for public health. However, significant decrease in sperm volume, sperm concentration, and total sperm in ejaculate has been noted. The current data, though, are limited, and more studies with longer follow-up are needed to evaluate the further impact.

COVID-19 and its treatments: lights and shadows on testicular function

PURPOSE

The SARS-CoV-2 pandemic has rapidly spread worldwide and, among the others, the male gender was quickly recognized as an independent risk factor for both the disease and its consequences. Since the possibility of long-term hormonal axis changes and male gamete impairment have been hypothesized but a relatively low levels of evidence has been reached, we focused this narrative mini-review on summarizing key state-of-the-art knowledge on male reproductive effects of COVID-19 as a quick reference for reproductive health specialists.

METHODS

A comprehensive Medline/PubMed and Embase search was performed selecting all relevant, peer-reviewed papers in English published from 2020. Other relevant papers were selected from the reference lists.

RESULTS

Available evidence indicates that the likelihood of direct testicular damage from SARS-CoV-2 is somewhat low, but there are many indirect ways (fever, cytokine imbalance, and drugs) through which the pituitary-gonadal axis and spermatogenesis may be disrupted. These alterations are probably transient, but as available evidence is low quality, it cannot be excluded that previous pathologies or comorbidities might modulate the risk of their persistence. On the other hand, available evidence shows high safety regarding andrological health for available vaccines, although studies are mainly focused on mRNA vaccines.

CONCLUSION

A careful andrological evaluation of men recovering from COVID-19 is highly recommended. Since available evidence is relatively scarce, a careful andrological follow-up and counseling of these patients are mandatory.

Semen parameters and male reproductive potential are not adversely affected after three or more months of recovery from COVID-19 disease

Background

The male reproductive system may be a potential target for SARS-CoV-2 since the presence of ACE and TMPRS2 receptors. After a first report of the presence of SARS-CoV-2 in semen of COVID-19 patients, several papers reported that SARS-CoV-2 was not detected in the semen. However, some evidences indicated that COVID-19 disease could impair semen parameters. During the infection, or in a short period after, a reduction in sperm concentration and motility and an increase in DNA fragmentation were observed, even in asymptomatic patients. There is no conclusive data exploring whether this damage changes with time. We investigated whether COVID-19 disease has a negative impact on semen parameters and male reproductive potential after recovery.

Methods

In this longitudinal retrospective study, we enrolled 20 men who had COVID-19 disease. We compared sperm parameters in samples collected before COVID-19 and after infection (8.3 ± 4.8 months). We also evaluated the reproductive potential in pre- and post-COVID-19 infertility treatments of 8 self-controlled couples as well as in 40 cycles after COVID-19 infection of the male partner.

Results

For most patients, we obtained results of more than one semen analysis before and after COVID-19. After adjusting for age, days of sexual abstinence, frequency of ejaculations and presence of fever, we found no significant difference over time in any semen parameter. The interval between COVID-19 infection and subsequent infertility treatments was 10.7 ± 7.5 months. There were no differences in the embryological and clinical outcomes of infertility treatments performed before and after male infection. One couple obtained a single pregnancy in the post COVID-19 IUI. Normal fertilization (65%), cleavage (99%) and blastocyst development (40%) rates in treatments performed after male infection were within the expected range of competencies. A total of 5 singleton and 1 twin clinical pregnancies were obtained, and 6 healthy children were born. A total of 10 blastocysts have been cryopreserved.

Conclusion

Our data are reassuring that COVID-19 disease has no negative effect on semen quality and male reproductive potential when semen samples are collected three months or more after infection.

Male reproductive health after 3 months from SARS-CoV-2 infection: a multicentric study

PURPOSE

While SARS-CoV-2 infection appears not to be clinically evident in the testes, indirect inflammatory effects and fever may impair testicular function. To date, few long-term data of semen parameters impairment after recovery and comprehensive andrological evaluation of recovered patients has been published. The purpose of this study was to investigate whether SARS-CoV-2 infection affect male reproductive health.

METHODS

Eighty patients were recruited three months after COVID-19 recovery. They performed physical examination, testicular ultrasound, semen analysis, sperm DNA integrity evaluation (TUNEL), anti-sperm antibodies (ASA) testing, sex hormone profile evaluation (Total testosterone, LH, FSH). In addition, all patients were administered International Index of Erectile Function questionnaire (IIEF-15). Sperm parameters were compared with two age-matched healthy pre-COVID-19 control groups of normozoospermic (CTR1) and primary infertile (CTR2) subjects.

RESULTS

Median values of semen parameters from recovered SARS-CoV-2 subjects were within WHO 2010 fifth percentile. Mean percentage of sperm DNA fragmentation (%SDF) was 14.1 ± 7.0%. Gelatin Agglutination Test (GAT) was positive in 3.9% of blood serum samples, but no positive semen plasma sample was found. Only five subjects (6.2%) had total testosterone levels below the laboratory reference range. Mean bilateral testicular volume was 31.5 ± 9.6 ml. Erectile dysfunction was detected in 30% of subjects.

CONCLUSION

Our data remark that COVID-19 does not seem to cause direct damage to the testicular function, while indirect damage appears to be transient. It is possible to counsel infertile couples to postpone the research of parenthood or ART procedures around three months after recovery from the infection.

COVID-19 and Semen Fluid Parameters, a Retrospective Study from Infertility Clinics

The study of the effects of SARS-CoV-2 infection and/or vaccination on semen fluid analysis (SFA) parameters is still incomplete. The aim of this study is to assess the effect of COVID-19 infection and vaccination on sperm parameters for a sample of individuals visiting multi-infertility clinics in Jordan. SFA records were collected retrospectively between September and November 2021 and analyzed using Jamovi software (version 2.2.5 for Windows); p-values < 0.05 were considered statistically significant. Sperm concentration, progressive motility, normal morphology, and semen liquefaction time, volume, and viscosity were compared among two data categories. In the first category of data, SFA records from 354 participants were separated into four groups: only vaccinated, infected and vaccinated, neither infected nor vaccinated, and only infected. In the other category, SFA from 49 subjects before their infection and/or vaccination and after were classified into the same mentioned groups and analyzed. There were no statistically significant differences between the studied parameters in the SFA records in the first data category and the second. Nevertheless, the sperm concentration was higher among vaccinated subjects compared to unvaccinated ones (p = 0.04). It is concluded that SARS-CoV-2 infection and vaccines have no negative effects on SFA parameters.

Role of SARS-CoV-2-induced Cytokine Storm in Multi-Organ Failure: Molecular Pathways and Potential Therapeutic Options

Coronavirus disease 2019 (COVID-19) outbreak has become a global public health emergency and has led to devastating results. Mounting evidence proposes that the disease causes severe pulmonary involvement and influences different organs, leading to a critical situation named multi-organ failure. It is yet to be fully clarified how the disease becomes so deadly in some patients. However, it is proven that a condition called “cytokine storm” is involved in the deterioration of COVID-19. Although beneficial, sustained production of cytokines and overabundance of inflammatory mediators causing cytokine storm can lead to collateral vital organ damages. Furthermore, cytokine storm can cause post-COVID-19 syndrome (PCS), an important cause of morbidity after the acute phase of COVID-19. Herein, we aim to explain the possible pathophysiology mechanisms involved in COVID-19-related cytokine storm and its association with multi-organ failure and PCS. We also discuss the latest advances in finding the potential therapeutic targets to control cytokine storm wishing to answer unmet clinical demands for treatment of COVID-19.

Evidence mapping and review of long-COVID and its underlying pathophysiological mechanism

PURPOSE

Apart from the global disease burden of acute COVID-19 disease, the health complications arising after recovery have been recognized as a long-COVID or post-COVID-19 syndrome. Evidences of long-COVID symptoms involving various organ systems are rapidly growing in literature. The objective was to perform a rapid review and evidence mapping of systemic complications and symptoms of long-COVID and underlying pathophysiological mechanisms.

METHODS

Publications reporting clinical trials, observational cohort studies, case-control studies, case-series, meta-analysis, and systematic reviews, focusing on the squeal of the disease, consequences of COVID-19 treatment/hospitalization, long-COVID, chronic COVID syndrome, and post acute COVID-19 were reviewed in detail for the narrative synthesis of frequency, duration, risk factors, and pathophysiology.

RESULTS

The review highlights that pulmonary, neuro-psychological, and cardiovascular complications are major findings in most epidemiological studies. However, dysfunctional gastrointestinal, endocrine, and metabolic health are recent findings for which underlying pathophysiological mechanisms are poorly understood. Analysis of the clinical trial landscape suggests that more than 50% of the industry-sponsored trials are focused on pulmonary symptoms. In contrast to the epidemiological trends and academic trials, cardiovascular complications are not a focus of industry-sponsored trials, suggestive of the gaps in the research efforts.

CONCLUSION

The gap in epidemiological trends and academic trials, particularly concerning cardiovascular complications not being a focus of industry-sponsored trials is suggestive of the gaps in research efforts and longer follow-up durations would help identify other long-COVID-related health issues such as reproductive health and fertility.

Examining changes on testicular structure and sperm analysis of COVID-19 patients

This study aimed to examine the testicular functions with sperm analysis of patients with COVID‐19. The study was carried out with male patients aged between 18 and 50 years with positive RT‐PCR test and SARS‐CoV‐2 virus between December 2020 and April 2021. A total of 103 participants were included in the study. The mean age was 31.24 ± 5.67 (19–45) years and the mean body mass index of the participants was 28.41 ± 4.68 kg/m². The patients were divided into two groups, group‐1 was patients who had COVID‐19, group‐2 was healthy men. A semen analysis of both groups was performed, and the serum total testosterone, FSH, LH, anti‐mullerian hormone and Inhibin‐B tests were analysed and recorded. The testicular dimensions and testicular densities were examined by ultrasound and elastography for both groups. Comparing the patient and control groups results, this study found that the sperm count per 1 cc (p = 0.01) and total motility (p = 0.01) in group‐1 was lower than in the control group, the testicular dimensions decreased (for right testis group‐2 was 15.39 ± 4.78 ml versus group‐1 was 12.11 ± 4.62 cm³p < 0.01, for left testis group‐2 was 16.01 ± 5.12 versus group‐1 was 11.92 ± 4.78 cm³; p < 0.01), and the shear wave velocities were significantly higher in group‐1 patients. In conclusion, sperm parameters deteriorate in men who have symptomatic disease with SARS‐CoV‐2 infection. The fact that the cause of this deterioration is characterized by changes at the cellular level in the testis raises doubts about the persistence of this condition.

Semen parameters and sex hormones as affected by SARS-CoV-2 infection: A systematic review

Background

Impaired semen quality and reproductive hormone levels were observed in patients during and after recovery from coronavirus disease 2019 (COVID-19), which raised concerns about negative effects on male fertility. Therefore, this study systematically reviews available data on semen parameters and sex hormones in patients with COVID-19.

Methods

Systematic search was performed on PubMed and Google Scholar until July 18th, 2022. We identified relevant articles that discussed the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on male fertility.

Results

A total number of 1,684 articles were identified by using a suitable keyword search strategy. After screening, 26 articles were considered eligible for inclusion in this study. These articles included a total of 1,960 controls and 2,106 patients. When all studies were considered, the results showed that the semen parameters and sex hormone levels of patients infected with SARS-CoV-2 exhibited some significant differences compared with controls. Fortunately, these differences gradually disappear as patients recover from COVID-19.

Conclusion

While present data show the negative effects of SARS-CoV-2 infection on male fertility, this does not appear to be long-term. Semen quality and hormone levels will gradually increase to normal as patients recover.

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.

Semen parameters after SARS-CoV-2 infection: A literature review

Background and Aims

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to affect multiple organs by binding to angiotensin-converting enzyme 2 receptors and might therefore affect male fertility. This review aims to collect all original articles on the effects of SARS-CoV-2 infection on male fertility, including the duration of time after infection required for these effects to begin to manifest and recommend how clinicians should approach cases with a recent illness.

Methods

This review was developed according to the preferred reporting items for systematic reviews and meta-analyses guidelines. The search string was applied to four online databases-namely Pubmed, Embase, Medline, and the Cochrane COVID-19 Register-and screened using the online tool Covidence.org. Articles were eligible for inclusion if they were cohort studies involving a healthy male population diagnosed with COVID-19, each of whom had semen samples collected before and after the infection or two different semen samples collected after the diagnosis.

Results

Nine cohort studies were eventually included. Five articles had pre- and post-COVID-19 data while four had two sets of post-COVID-19 data. The three largest studies found a statistically significant decrease in all semen parameters when waiting less than 3 months from diagnosis before sample collection, and no significant differences in results when the ejaculate was analyzed more than 3 months after recovery. One study compared the COVID-19 patients with a control group and found a significant decrease in semen parameters in the COVID-19 group.

Conclusion

Spermatogenesis seems to be affected by SARS-CoV-2 infection, but the impact tends to reverse within 3-4 months. It is still unclear why male fertility is affected by SARS-CoV-2 infection, and it might be the result of several different components. Clinicians should consider recent SARS-CoV-2 infection as a possible reason for the low semen quality of patients' semen samples, and might therefore need to collect new samples after 4 months before further treatment.

A Prospective Cohort Study of COVID-19 Vaccination, SARS-CoV-2 Infection, and Fertility

Some reproductive-aged individuals remain unvaccinated against coronavirus disease 2019 (COVID-19) because of concerns about potential adverse effects on fertility. Using data from an internet-based preconception cohort study, we examined the associations of COVID-19 vaccination and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with fertility among couples trying to conceive spontaneously. We enrolled 2,126 self-identified female participants aged 21-45 year residing in the United States or Canada during December 2020-September 2021 and followed them through November 2021. Participants completed questionnaires every 8 weeks on sociodemographics, lifestyle, medical factors, and partner information. We fit proportional probabilities regression models to estimate associations between self-reported COVID-19 vaccination and SARS-CoV-2 infection in both partners with fecundability (i.e., the per-cycle probability of conception), adjusting for potential confounders. COVID-19 vaccination was not appreciably associated with fecundability in either partner (female fecundability ratio (FR) = 1.08, 95% confidence interval (CI): 0.95, 1.23; male FR = 0.95, 95% CI: 0.83, 1.10). Female SARS-CoV-2 infection was not strongly associated with fecundability (FR = 1.07, 95% CI: 0.87, 1.31). Male infection was associated with a transient reduction in fecundability (for infection within 60 days, FR = 0.82, 95% CI: 0.47, 1.45; for infection after 60 days, FR = 1.16, 95% CI: 0.92, 1.47). These findings indicate that male SARS-CoV-2 infection may be associated with a short-term decline in fertility and that COVID-19 vaccination does not impair fertility in either partner.

A Systemic Review and Meta-analysis of the Effect of SARS-CoV-2 Infection on Sperm Parameters

Objective. Several studies examined the putative effects of SARS-CoV-2 infection on sperm parameters. However, the results remain controversial. In this study, we conducted the most up-to-date systematic review and meta-analysis to investigate the effect of SARS-CoV-2 infection on sperm quality in COVID-19-positive and COVID-19-negative male participants. Method. Seven databases were searched for literature released through June 10, 2022, containing estimates for the outcomes of interest. Using a random-effects model (REM) or a fixed-effects model (FEM), we analyzed the pooled results. The quality of all included studies was assessed by the Newcastle-Ottawa scale. In addition, we performed a quantitative and subgroup analysis of semen data across all included studies. Results. Fourteen studies were extracted from 10 publications, involving a total of 1174 participates for meta-analysis. Sperm parameters of 521 COVID-19 male patients and 653 controls were analyzed. In 8 case-control studies, the pooled mean difference (MD) of total sperm motility was -5.37% (95% confidence interval (CI): -8.47 to -2.28; p < 0.05 ), suggesting that total motility was significantly impaired in male COVID-19 cases. Subgroup analysis showed a significant decrease in semen volume, sperm concentration, and total motility in 238 patients with a recovery time of less than 90 days. Moreover, in the other 6 included pre- to post-COVID-19 studies, the pooled MDs of sperm concentration, total sperm count, total motility, progressive motility, and normal morphology were - 6.54 × 10 6/ml (95% CI: -10.27 to -2.81; p < 0.05 ), - 38.89 × 10 6 (95% CI: -59.20 to -18.58; p < 0.05 ), -7.21% (95% CI: -14.36 to -0.07; p < 0.05 ), -5.12% (95% CI: -8.71 to -1.53; p < 0.05 ), and -1.52% (95% CI: -2.88 to -0.16; p < 0.05 ), respectively, which indicate SARS-CoV-2 infection significantly affected these five sperm parameters. Conclusion. Our results revealed that SARS-CoV-2 infection was significantly correlated with decreased sperm quality. Of six sperm parameters, total motility and sperm concentration were the most significantly decreased parameters. These results suggest a possible negative influence of SARS-CoV-2 infection on testicular function and male fertility. Given the potential detrimental effect of SARS-CoV-2 on semen quality, male reproductive health should be monitored closely in patients with COVID-19. This trial is registered with CRD42021275823.

SARS-CoV-2 effects on sperm parameters: a meta-analysis study

AIM

The rapid outbreak of the coronavirus disease 2019 (COVID-19) pandemic posed challenges across different medical fields, especially reproductive health, and gave rise to concerns regarding the effects of SARS-CoV-2 on male infertility, owing to the fact that the male reproductive system indicated to be extremely vulnerable to SARS-CoV-2 infection. Only a small number of studies have investigated the effects of SARS-CoV-2 on male reproduction, but the results are not consistent. So, we performed this meta-analysis to draw a clearer picture and evaluate the impacts of COVID-19 on male reproductive system.

METHOD

We searched Embase, Web of Science, PubMed, and Google Scholar databases to identify the potentially relevant studies. Standardized mean difference (SMD) with 95% confidence interval (CI) was applied to assess the relationship. Heterogeneity testing, sensitivity analysis, and publication bias testing were also performed.

RESULTS

A total of twelve studies including 7 case control investigations and 5 retrospective cohort studies were found relevant and chosen for our research. Our result showed that different sperm parameters including semen volume [SMD =  - 0.27 (- 0.46, - 1.48) (p = 0.00)], sperm concentration [SMD =  - 0.41 (- 0.67, - 0.15) (p = 0.002)], sperm count [SMD =  - 0.30 (- 0.44, - 0.17) (p = 0.00)], sperm motility [SMD =  - 0.66 (- 0.98, - 0.33) (p = 0.00)], and progressive motility [SMD =  - 0.35 (- 0.61, - 0.08) (p = 0.01)] were negatively influenced by SARS-CoV-2 infection. However, sperm concentration (p = 0.07) and progressive motility (p = 0.61) were not found to be significantly associated with SARS-CoV-2 infection in case control studies. No publication bias was detected.

CONCLUSION

The present study revealed the vulnerability of semen quality to SARS-CoV-2 infection. Our data showed a strong association of different sperm parameters with SARS-CoV-2 infection. The results suggested that SARS-CoV-2 infection in patients may negatively influence their fertility potential in a short-term period, but more studies are needed to decide about the long-term effects.

Investigate the effect of COVID-19 inactivated vaccine on sperm parameters and embryo quality in in vitro fertilization

Since the reproductive toxicity of COVID‐19 vaccines have not been assessed in previous clinical trials, and studies have shown that SARS‐CoV‐2 is associated with a decrease in sperm parameters. Although it has been reported that the mRNA SARS‐CoV‐2 vaccines do not adversely affect semen parameters, whether this conclusion applies to inactivated vaccines remains unclear. Here, we conducted a study among patients who accepted in vitro fertilization (IVF) at the reproductive centre between June and August of 2021. In the enrolled cases, men who have completed two doses of COVID‐19 inactivated vaccine were included in “vaccine group” (N = 105), and those who were not vaccinated were included in “control group” (N = 155). In this study, we compare the sperm parameters and embryo quality between these two groups. Our data showed that the sperm parameters were similar in terms of volume, sperm concentration, sperm count, progressive motility, total motility and total motile sperm count between these two groups. Similarly, no significant differences were observed in IVF outcomes. The mean number of 2PN, cleavage‐stage embryos, blastocysts, and good‐quality blastocysts was 8.59 ± 4.47, 5.06 ± 3.17 and 2.08 ± 1.79 in vaccine group, 7.75 ± 4.14, 4.34 ± 3.06 and 1.74 ± 1.54 in control group, respectively. The high‐quality blastocyst rate was 41.05% (218 of 531) in vaccine group and 40.03% (269 of 672) in control group (p > 0.05). In addition, no differences were observed in biochemical and clinical pregnancy rates between the two groups. In summary, our results revealed that COVID‐19 inactivated vaccine administration exhibited no negative effect on sperm parameters and embryo quality in IVF.

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.

Could SARS-CoV-2 infection affect male fertility and sexuality?

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is the cause of coronavirus infectious disease (COVID‐19) and has rapidly spread worldwide, causing serious problems to the healthcare systems of many countries and hundreds of thousand deaths. In this review we discuss data from the literature to understand whether the various districts of the male reproductive system may represent another vulnerable target for SARS‐CoV‐2. Studies were searched from electronic databases such as Google Scholar, PubMed, Scopus, and COVID‐19 specific databases such as LitCovid, until July 31, 2021. It appears that SARS‐CoV‐2 virus infection not only causes damage to the respiratory system, but could have a serious impact on the reproductive system of male patients modulating many physiological processes. Like some other infections, SARS‐CoV‐2 also leads to a worsening of semen quality and an increase in oxidative stress (OS) levels. However, due to the limited number of studies, it is unclear whether this deterioration in semen parameters is temporary or lasts over time. It is certainly important that patients' reproductive function is monitored after coronavirus infection to avoid problems in reproductive health in the future.

Impact of COVID-19 on male fertility

COVID-19, the clinical condition caused by the SARS-CoV-2 virus, has been associated with massive cytokine storm and damage to multiple organ systems. Although evidence for the detection of SARS-CoV-2 virus in the testis remains scarce, testicular damage and dysregulation of gonadotropins associated with inflammation has been reported. Additionally, as a result of the rapidly evolving pandemic, frequently updated medical interventions and public policies leading to delays of care can play a role in fertility. This narrative review aims to summarize the current literature on how COVID-19 may influence male fertility.