Effects of mild/asymptomatic COVID-19 on semen parameters and sex-related hormone levels in men: a systematic review and meta-analysis

Effect of SARS-CoV-2 on semen parameters: A meta-analysis of 39 articles from 15 countries

Background

Declining birth rates during the pandemic have led to concerns about the potential impact of the of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on fertility among men. As previous studies have had inconsistent conclusions, we conducted a meta-analysis to evaluate the effects of SARS-CoV-2 on semen parameters.

Methods

We searched several databases for articles published between 1 January 2020 and 25 July 2023. We performed a robust screening process based on predetermined inclusion and exclusion criteria and, following quality assessment, extracted data from high-quality studies for the meta-analysis. We determined the P-values and 95% confidence intervals (CIs) for both continuous and dichotomous variables, which we described using mean differences (MDs) and odds ratios (ORs), respectively. Lastly, we used the leave-one-out approach for our sensitivity analysis, and Begg's and Egger's tests to determine publication bias.

Results

We included 39 articles with 1887 cases and 2097 controls. In patients infected with SARS-CoV-2, the sperm volume (MD = -0.29; 95% CI = -0.50, -0.07; P = 0.008) and concentration (MD = -8.71; 95% CI = -16.94, -0.48; P = 0.04) were decreased, which increased oligospermia risk (OR = 2.49; 95% CI = 1.04, 5.99; P = 0.04). Furthermore, we observed reduced sperm motility (MD = -8.18; 95% CI = -12.19, -4.17; P < 0.001) and increased immotility (MD = 4.06; 95% CI = 1.57, 6.54; P = 0.001) in infected patients, which increased asthenospermia risk (OR = 3.86; 95%CI = 1.83, 8.14; P = 0.0004). We also saw a decreased proportion of semen with normal sperm morphology (MD = -1.67; 95% CI = -2.68, -0.66; P = 0.001) and an increased proportion of semen with abnormal sperm morphology (MD = -1.31; 95% CI = -2.14, -0.49; P = 0.002,), along with increases in teratospermia (OR = 1.98; 95% CI = 1.00, 3.92; P = 0.05) in infected compared non-infected patients. Although we found consistency within most subgroups, we observed differences in severity, follow-up time, and country of origin. The results of the main meta-analysis results remained stable in the sensitivity analysis, while Begg's and Egger's tests showed no publication bias.

Conclusions

Based on sufficient evidence, we see that the effects of SARS-CoV-2 on semen parameters resulted in a decline in male fertility. The increased severity and shorter duration of the SARS-CoV-2 infection increased the likelihood of altering of semen parameters.

Registration

INPLASY: INPLASY202420083.

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.

Comprehensive evaluation of inactivated SARS-CoV-2 vaccination on sperm parameters and sex hormones

Background

The inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine has made significant contributions to fighting the epidemic in the past three years. However, the rapid development and application raised concerns about its safety in reproductive health, especially after several studies had observed a decrease in semen parameters following two doses of mRNA SARS-CoV-2 vaccination. Thus, it is necessary to comprehensively evaluate the effect of inactivated SARS-CoV-2 vaccine on male fertility.

Methods

A retrospective cohort study was conducted in the Center for Reproductive Medicine of the Affiliated Hospital of Jining Medical University between July 2021 and March 2023. A total of 409 men with different vaccination status and no history of SARS-CoV-2 infection were included in this study. Their sex hormone levels and semen parameters were evaluated and compared separately.

Results

The levels of FSH and PRL in one-dose vaccinated group were higher than other groups, while there were no significant changes in other sex hormone levels between the control and inactivated SARS-CoV-2 vaccinated groups. Most semen parameters such as volume, sperm concentration, total sperm count, progressive motility and normal forms were similar before and after vaccination with any single dose or combination of doses (all P > 0.05). Nevertheless, the total motility was significantly decreased after receiving the 1 + 2 doses of vaccine compared to before vaccination (46.90 ± 2.40% vs. 58.62 ± 2.51%; P = 0.001). Fortunately, this parameter was still within the normal range.

Conclusion

Our study demonstrated that any single dose or different combined doses of inactivated SARS-CoV-2 vaccination was not detrimental to male fertility. This information could reassure men who want to conceive after vaccination and be incorporated into future fertility recommendations.

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.

SARS-CoV-2 infection (COVID-19) and male fertility: Something we should be worried about?

As of 2021, roughly 5 million deaths were linked to SARS-CoV-2 infection based on World Health Organization estimates. The pandemic takes its staggering death toll, severely affecting the healthcare systems and leading to detrimental implications globally. While the severe impact on the respiratory system is well-established, the exact effect on male reproduction is still largely uncharted territory. When it comes to gender, men appear more vulnerable compared to women. Increasing evidence suggests that COVID-19 adversely affects spermatogenesis and hormonal balance in diverse ways. Semen parameters seem to be compromised at least temporarily, while long-term worsening needs to be clarified in studies with extended follow-up. For the time being, no data support the adverse effect of COVID-19 vaccines on a male's reproductive health. In the present article, we examine the available literature and briefly discuss the impact of the virus on reproduction and fertility. We further provide a comprehensive overview of the current status of vaccination and its potential effect on male fertility. Ultimately, we address the need for future well-designed large-scale trials before drawing definite conclusions on the exact impact of the virus on a male's fecundity.

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.

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.

Mild COVID-19 Was Not Associated with Impaired IVF Outcomes or Early Pregnancy Loss in IVF Patients

Data collection regarding the effects of COVID-19 on reproduction is ongoing. This study examined the effect of COVID-19 on IVF cycle parameters and early pregnancy outcomes. It included two arms: the first compared non-exposed cycles to post-SARS-CoV-2 IVF cycles. Sperm parameters were also compared. The second, prospective arm compared pregnancy outcomes among IVF patients who contracted COVID-19 during early pregnancy to those who did not. None of the patients were vaccinated against SARS-CoV-2. The first arm included 60 treatment cycles of women with confirmed COVID-19, compared to 60 non-exposed cycles (either the same patient before exposure or matched non-exposed patients). The outcomes of the treatment cycles did not differ significantly between exposed and non-exposed groups, including number of oocytes, endometrial thickness, fertilization rate and number of top-quality embryos. In 11 cycles, the male partner had also recently recovered: sperm concentration was lower post-exposure: 6.27 million/mL vs. 16.5 pre-exposure (p = 0.008). In 189 patients with IVF-achieved pregnancies, pregnancy loss and hospital admissions did not differ between exposed and non-exposed groups. IVF treatment outcomes and the rate of early pregnancy loss appears to be unaffected by SARS-CoV-2 disease, despite a minor decline in sperm concentration among recent recoverees.