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

Background: Although the pandemic of the new coronavirus infection (COVID-19) is characterized by mostly mild and asymptomatic cases (more than 80%), it appears important to assess the potential risks for the male reproductive system, in particular, for the parameters of the sperm. Aim: To study the effect of a mild and asymptomatic course of the new coronavirus infection (COVID-19) on the male sperm's parameters. Methods: The study included 397 patients who applied for a spermogram. All the patients underwent a spermogram study according to the WHO protocol, with the additionally measured degree of sperm DNA fragmentation, acrosine activity, fructose level, zinc level, citric acid level, neutral-glucosidase activity. A test for sperm binding to hyaluronic acid (HBA test) was performed, and the serum antibodies (IgM and IgG) against SARS-CoV-2 were analyzed. The study was conducted twice with an interval of 3–5 months. Results: At the first examination, normozoospermia was found in 33.5% (n=133) of patients, pathospermia — in 66.5% (n=264). All the patients had no antibodies against SARS-CoV-2 (COVID-19). When the analysis was repeated after 3–5 months, antibodies (IgG) against SARS-CoV-2 were detected in 144 patients: in 14.6% (n=21) the coronavirus infection was mild, and in 85.4% (n=123) it was asymptomatic. Those patients who received some type of a treatment (andrologic, anticovid, and/or other) were excluded from the further study. The subsequent analysis of the data from the untreated patients (131 patients without antibodies against SARS-CoV-2 and 93 patients with antibodies (IgG) against SARS-CoV-2) was performed using the Student's paired test. For all the parameters of the standard spermogram according to the WHO protocol, the found changes after the mild and asymptomatic form of COVID-19 were not statistically significant. Also, the changes in the degree of fragmentation of sperm DNA, the enzymatic activity of acrosine, and other estimated parameters of the sperm (levels of fructose, citric acid, zinc, and the activity of neutral-glucosidase) were not statistically significant. The results of the test for the spermatozoa's interaction with hyaluronic acid (HBA test) worsened and had statistically significant differences after the coronavirus infection in both the mild form (p=0.006) and asymptomatic form (p=0.001). There were no statistically significant changes in the sperm parameters (including those from the HBA test) in the patients who had not had the new coronavirus infection. Conclusions: No statistically significant data were obtained on the effect of mild and asymptomatic forms of the course of the new coronavirus infection on the parameters of the standard spermogram, on the degree of fragmentation of spermatozoa's DNA and the enzymatic activity of acrosin. Mild and asymptomatic forms of the new coronavirus infection course can negatively affect the interaction of spermatozoa with hyaluronic acid (HBA test), that indicates the impairment of the spermatozoa binding to the zona pellucida. One should pay attention to the HBA test when examining the sperm of patients who have suffered the new coronavirus infection.