Association between COVID-19 and Male Fertility: Systematic Review and Meta-Analysis of Observational Studies

Zinc as a Possible Critical Element to Prevent Harmful Effects of COVID-19 on Testicular Function: a Narrative Review

Research into innovative non-pharmacological therapeutic routes via the utilization of natural elements like zinc (Zn) has been motivated by the discovery of new severe acute respiratory syndrome-related coronavirus 2 (SARS-COV2) variants and the ineffectiveness of certain vaccination treatments during COVID-19 pandemic. In addition, research on SARS-COV-2's viral cellular entry and infection mechanism has shown that it may seriously harm reproductive system cells and impair testicular function in young men and adolescents, which may lead to male infertility over time. In this context, we conducted a narrative review to give an overview of the data pertaining to Zn's critical role in testicular tissue, the therapeutic use of such micronutrients to enhance male fertility, as well as in the potential mitigation of COVID-19, with the ultimate goal of elucidating the hypothesis of the potential use of Zn supplements to prevent the possible harmful effects of SARS-COV2 infection on testis physiological function, and subsequently, on male fertility.

COVID-19 and Oncofertility: No SARS-CoV-2 in Semen but Inflammation Seems to Affect Sperm Parameters

The COVID-19 pandemic, driven by SARS-CoV-2, led authorities to recommend halting assisted reproductive technology programs, focusing instead on fertility preservation, for cancer patients. The presence of SARS-CoV-2 in semen remains controversial. This multicentric prospective cohort study, conducted across 12 university medical centers, aimed to determine if SARS-CoV-2 is present in spermatozoa/seminal plasma in cancer patients by RT-PCR and to assess its impact on standard semen parameters. The levels of cytokines and TNF-α were measured in seminal fluid by ELISA. We enrolled 129 men who underwent sperm cryopreservation between July 7, 2020, and June 30, 2021. The 63 were included and tested for COVID-19 in nasal swab samples by RT-PCR and/or by serology. All patients were asymptomatic on the day of semen collection: 50 were uninfected, 8 had a positive nasal swab (PCR+) and 5 were seropositive. SARS-CoV-2 RNA was not detected in the seminal fluid or spermatozoa. Ejaculate volume was significantly lower in the PCR+ group compared to the uninfected group (median [IQR]: 2.6 mL [1.6-3.4] vs. 4.6 mL [2.6-5.2] p < 0.05). Total and progressive motility were lower in the PCR+ group compared to the seropositive group (32.5% [25.0-45.0] vs. 50% [49.0-55.0] p < 0.05, and 22.5% [10.0; 32.5] vs. 44.5% [40-49] p < 0.05). Higher TNF-α level was observed in the PCR+ group (1.9 pg/mL [0-3.9]) compared to the uninfected group (0 pg/mL [0-0.4]) p < 0.05. Although SARS-CoV-2 was not detected in the sperm samples of cancer patients who were PCR+, the infection appears to impact sperm parameters, likely due to inflammation.

Sperm quality and sexual function after the first COVID-19 infection during the omicron surge: an observational study in southwest China

Background

As the Omicron variant became the dominant coronavirus disease 2019 (COVID-19) strain and the threat to human health decreased, the impact of COVID-19 on male reproductive health and semen quality may have changed. In this prospective observational study, we aimed to investigate the changes in semen quality and sexual function before and after the Omicron variant infection by self-controlled study and to explore the influence of Omicron variant infection on male reproductive health.

Methods

We recruited 373 participants who provided semen samples before their first COVID-19 infection. During the subsequent follow-up, only 154 participants provided the second semen samples, 11 of whom were not infected with COVID-19. Sperm quality was assessed approximately 45 and 90 days after COVID-19, as well as before infection.

Results

Semen parameters, including total sperm count, total forward sperm, progressive motility, and sperm concentration, significantly declined 45 days after COVID-19 infection. At 90 days after infection, the total sperm count, total forward sperm, and sperm concentration gradually increased to pre-infection levels. Participants who experienced fever showed worse semen quality in terms of total forward sperm, sperm concentration, and sperm progressive rate. However, this phenomenon was not observed in the other group infected with COVID-19 without fever or not infected. In addition, 49 (34.3%) of 143 persons confirmed that the COVID-19 infection resulted in changes in sexual function, with an increase in premature ejaculation diagnostic tool (PEDT) scores.

Conclusions

The results of our self-controlled study indicate that COVID-19 is associated with impaired semen quality early after disease onset. After 1-2 spermatogenesis cycles, the semen quality gradually recovers from the infection. These findings are beneficial for better understanding the COVID-19-associated sequelae, which are fundamental for semen collection during assisted reproduction.

Mild coronavirus disease 2019: Results of a multicentric prospective study on severe acute respiratory syndrome coronavirus 2 presence in semen fractions and cells and its effects on semen parameters

BACKGROUND

Severe acute respiratory syndrome coronavirus 2, the virus responsible for coronavirus disease 2019, affects multiple organs. The virus enters cells through angiotensin-converting enzyme-2 and host factors present in genital organs, leading to concern over virus shedding in semen and reproductive function.

OBJECTIVES

To investigate severe acute respiratory syndrome coronavirus 2 in semen from patients with a mild infection, identify the seminal infected cells, and explore the effect of the infection on sex hormones and semen parameters.

MATERIALS AND METHODS

Prospective study of 54 men with mild severe acute respiratory syndrome coronavirus 2 infection. Semen was collected at 7, 15, 30, 60, 90, 180, and 365 days after symptom onset, and severe acute respiratory syndrome coronavirus 2 RNA was measured in serum, saliva, urine, and semen. The presence of infectious severe acute respiratory syndrome coronavirus 2 in semen was assessed using Vero cell culture. Infected semen cells were identified using immunofluorescence against severe acute respiratory syndrome coronavirus 2 nucleoprotein antigen and cell markers. Semen characteristics as well as testosterone, inhibin B, luteinizing hormone, and follicle-stimulating hormone levels were determined.

RESULTS

11% of patients had at least one severe acute respiratory syndrome coronavirus 2 RNA-positive semen. One patient had viral semen shedding up to day 90 after infection onset, with replication-competent virus isolated from semen and 40% cell fraction at day 7. After sperm preparation, 90% fraction was severe acute respiratory syndrome coronavirus 2 RNA-positive at days 7 and 15. The swim-up fraction was positive only on day 7. In semen, nucleoprotein antigen was detected mainly in exfoliated epithelial cells and less frequently in Sertoli cells. Sperm count and motile sperm count were lower at day 30 than at day 7. Round cells in semen were increased during the acute phase. At days 7 and 15, sperm count and motile sperm count were lower in severe acute respiratory syndrome coronavirus 2 RNA-positive semen compared with negative semen, while semen volume and follicle-stimulating hormone levels were increased. Long-term follow-up shows no evidence of a detrimental effect on hormonal or semen characteristics.

DISCUSSION AND CONCLUSION

11% of patients with mild coronavirus disease 2019 who were not hospitalized had severe acute respiratory syndrome coronavirus 2 excretions in semen, which persisted for up to 90 days in one patient. No germ cells appeared infected by the virus, but the detection of nucleoprotein antigen-positive epithelial semen cells and Sertoli cells suggests genital tract infection. Albeit infrequent, semen may contain the replication-competent virus during the acute phase with potential risk of severe acute respiratory syndrome coronavirus 2 transmissions during sexual contact and assisted reproduction procedures. The effect of mild coronavirus disease 2019 on spermatogenesis and reproductive hormones was moderate and reversible.

Impact of COVID-19 on sperm quality and the prostaglandin and polyamine systems in the seminal fluid

BACKGROUND

The implications of SARS-CoV-2 infection on male fertility remain largely unknown. Besides their well-known pro- and anti-inflammatory actions, prostaglandins and polyamines are present in semen, where they play key roles in sperm quality.

OBJECTIVES

To analyze semen parameters, oxidative profile and the seminal fluid prostaglandin and polyamine systems in samples collected from individuals without coronavirus disease 2019 diagnosis and men who recovered from coronavirus disease 2019.

MATERIALS AND METHODS

This study compared semen collected from men without positive coronavirus disease 2019 diagnosis with samples obtained from individuals 1-6 months and 7-30 months post SARS-CoV-2 infection. Semen parameters, thiobarbituric acid reactive substances, cyclooxygenase 2 expression by fluorescence immunocytochemistry and immunoblotting, prostaglandin levels by enzyme immunoassay, ornithine decarboxylase activity by a radioactive assay, and polyamine and acetylated polyamine levels by thin-layer chromatography were assessed.

RESULTS

In both groups of semen samples from coronavirus disease 2019 recovered men, sperm vitality, total and progressive sperm motility, and putrescine levels were significantly decreased when compared with samples from the uninfected group. In contrast, lipid peroxidation, leukocyte-associated cyclooxygenase 2 expression, and prostaglandin D2 levels were higher in semen from coronavirus disease 2019 recovered men than in samples from uninfected individuals. While sperm concentration and morphology, ornithine decarboxylase activity, and N-acetylputrescine levels were statistically diminished in semen obtained up to 6 months after coronavirus disease 2019 recovery, these parameters remained unchanged when samples were collected 7-30 months after coronavirus disease 2019 recovery. Coronavirus disease 2019 vaccination did not show negative effects on any of the parameters evaluated.

DISCUSSION AND CONCLUSION

Our work provides insights into the detrimental impact of coronavirus disease 2019 on several sperm parameters, in some cases, even more than a year after SARS-CoV-2 infection, which would be accompanied by alterations in the seminal fluid prostaglandin and polyamine profiles. Therefore, future treatments targeting the prostaglandin and polyamine pathways in coronavirus disease 2019 recovered men could lead to a successful reinstatement of semen parameters.

Pulsatile Gonadotropin-Releasing Hormone Therapy Is Associated With Better Spermatogenic Outcomes than Gonadotropin Therapy in Patients With Pituitary Stalk Interruption Syndrome

OBJECTIVE

To compare the effects of combined gonadotropin and pulsatile gonadotropin-releasing hormone (GnRH) therapy on spermatogenesis in patients with pituitary stalk interruption syndrome (PSIS).

METHODS

Male patients with PSIS (N = 119) were retrospectively studied. Patients received pulsatile GnRH therapy (N = 59) were divided into response and poor-response groups based on luteinizing hormone (LH) levels after 1-month treatment with a cutoff value of 1 or 2 IU/L. Participants with gonadotropin therapy were divided into human menopausal gonadotropin (hMG)/human chorionic gonadotropin (hCG) group (N = 60), and patients with pulsatile GnRH therapy were classified into GnRH group (N = 28) with treatment duration ≥6 months.

RESULTS

The overall success rates of spermatogenesis for hMG/hCG and GnRH therapy were 51.67% (31/60) vs 33.90% (20/59), respectively. GnRH group required a shorter period to induce spermatogenesis (8 vs 15 months, P = .019). hMG/hCG group had higher median total testosterone than GnRH group [2.16, interquartile range(IQR) 1.06-4.89 vs 1.31, IQR 0.21-2.26 ng/mL, P = .004]. GnRH therapy had a beneficial effect on spermatogenesis compared to hMG/hCG therapy (hazard ratio 1.97, 95% confidence interval 1.08-3.57, P = .026). In patients with pulsatile GnRH therapy, compared with the poor-response group, the response group had a higher successful spermatogenesis rate (5.00% vs 48.72%, P = .002) and higher median basal total testosterone (0.00, IQR 0.00-0.03 vs 0.04, IQR 0.00-0.16 ng/mL, P = .026) with LH = 1 IU/L as the cutoff value after 1-month pulsatile GnRH therapy.

CONCLUSIONS

Pulsatile GnRH therapy was superior to hMG/hCG therapy for spermatogenesis in patients with PSIS. Earlier spermatogenesis and higher concentrations of sperm could be obtained in the GnRH group if patients received therapy over 6 months.

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.

Study of SARS-CoV-2 in semen from asymptomatic donors with the presence of virus in nasopharyngeal swabs

RESEARCH QUESTION

Is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present in semen samples from asymptomatic donors who have positive virus results from nasopharyngeal swabs?

DESIGN

Nasopharyngeal PCR was performed on 1943 sperm donors between January 2021 and March 2022. The result was positive for 140 donations, and the presence of SARS-CoV-2 could be studied in cryopreserved semen from 84 of these donors. This included 67 participants in whom the quality of fresh semen could be compared with the previous donation, the day of the PCR-positive nasopharyngeal sampling and the first subsequent donation. Semen donations were cryopreserved following total semen (n = 26) or ready-to-use (n = 58) protocols. The presence of SARS-CoV-2 in cryopreserved samples was determined by reverse transcription PCR. Semen quality (volume, concentration and progressive motility) was evaluated in accordance with World Health Organization 2010 recommendations.

RESULTS

SARS-CoV-2 virus was not detected in any cryopreserved total semen or ready-to-use samples. No significant differences in semen volume, concentration or progressive motility were observed between the last previous donation, the day of the positive PCR nasopharyngeal sampling and the first subsequent donation.

CONCLUSIONS

The lack of detection of SARS-CoV-2 in semen samples from asymptomatic individuals infected with SARS-CoV-2 supports the safety of assisted human reproduction treatments using this type of sample.

Effects of COVID-19 Infection on Spermatogenesis, Oxidative Stress and Erectile Function

BACKGROUND

Our aim was to evaluate the effect of COVID-19 infection on male fertility and sexual function.

METHODS

Thirty-one patients were investigated over a mean follow-up of 90 days (22-527) after a COVID-19 infection. Erectile dysfunction (ED), blood tests for sexual hormones, semen analysis including analysis of oxidative stress (OS), as well as COVID-19 antibody titer and the nasal COVID-19 PCR test were evaluated pre- and post-infection.

RESULTS

Five patients reported a mild de novo ED (16.13%). One patient had a de novo positive mixed antiglobulin reaction test after the infection. We found no significant difference between pre-COVID-19 and post-COVID-19 spermiogram parameters (p = 0.815). OS showed no significant association with COVID-19 infection, but with pathological spermiogram categories, sperm concentration, total sperm count, testis volume, FSH and testosterone.

CONCLUSION

COVID-19 infection does not appear to affect sperm quality and OS negatively in the intermediate term. Further investigations will be needed to assess the potential long-term effects of the infection and vaccination on male sexual function and fertility.

COVID-19 Vaccines and Assisted Reproductive Techniques: A Systematic Review

Objective: To review the current knowledge concerning COVID-19 vaccination and assisted reproductive techniques (ART). Methods: A systematic review in Pubmed-Medline, the Cochrane Database, the Web of Science, and the National Guideline was performed. Studies were selected if they were primary studies, included vaccinated (case) and unvaccinated (control) patients, and described fertility treatment response. Results: A total of 24 studies were selected. Outcomes related to the association between COVID-19 vaccination and ART were collected. The vast majority of studies found no statistical differences concerning oocyte stimulation response, embryo quality, implantation rates, or pregnancy outcome (clinical or biochemical pregnancy rates and losses) when comparing cases and controls. Similarly, no differences were found when comparing different types of vaccines or distinct ART (artificial insemination, in vitro fertilization, and embryo transfer of frozen embryos). Conclusions: Patients receiving ART and health care professionals should be encouraged to complete and recommend COVID-19 vaccination, as the available evidence regarding assisted reproductive outcomes is reassuring.