COVID-19 pandemic effects on seminal fluid analysis parameters: Comment

Dear Editor, the publication on “COVID-19 pandemic effects on seminal fluid analysis parameters: A prospective cohort study ¹ ” is hereby discussed. This study on the effects of COVID-19 infection on semen quality (SFA) indicators is significant since it highlights the pandemic’s potential long-term influence on male reproductive health. However, from an academic standpoint, there are methodological constraints and interpretations that must be questioned in order to acquire a better understanding.

First, the study’s sample size was reduced from 50 to 44 participants due to lack of follow-up. This resulted in a small sample size and potentially reduced statistical power, especially when comparing differences between subgroups like smokers and non-smokers or individuals with various body weight levels. The fact that more than 77% of the participants were smokers could possibly be a substantial confounder, given smoking is already linked to worse sperm quality. The absence of multivariate analysis makes it impossible to determine whether COVID-19 is a direct factor.

Second, while the research revealed a significant drop in SFA parameters before and after infection, it did not include a comparison to a control group, i.e., individuals who were not infected with COVID-19 over the same time period. The lack of a control group makes it impossible to rule out the impact of external factors such as stress, lifestyle changes during the pandemic, or other diseases that occurred during the same time period.

They should also assess the clinical importance, such as whether sperm count, concentration, or motility drops while remaining within the fertile range. The absence of data limits the practical use of these findings in clinical settings. Furthermore, sex hormone levels (e.g., testosterone, FSH, and LH) were not measured, which could have shed light on the mechanisms underlying semen alterations.

Third, the interpretation of the results should consider more than just statistical differences. From an analytical and clinical endpoint, the findings should be interpreted within a framework that distinguishes statistical significance from clinical relevance. Although statistically significant declines in SFA parameters were reported, the absence of stratified analysis according to fertility thresholds limits the ability to infer real-world reproductive risk. Clinicians require clarity on whether observed changes translate into subfertility or infertility, particularly in patients without pre-existing risk factors. Moreover, without hormonal profiling or adjustment for major confounders such as smoking intensity, body mas index, and post infection recovery time, causality cannot be reasonable inferred. A more rigorous analytical approach, incorporating multivariate modeling and clinically anchored outcome resources, would allow these findings to inform patient counseling, post-COVID fertility surveillance, and decision-making regarding the need for follow-up semen analysis or reproductive intervention. As currently presented, the results are hypothesis-generating rather than practice-changing.

Finally, this study suggests that COVID-19 may have an indirect effect on reproductive health, especially when paired with other risk factors like smoking and dietary status. Another question is whether these effects will last or can be reversed in the long run. A follow-up research 1-2 years after infection, with a clear comparison to a control group, would provide a more complete knowledge and potentially lead to suitable surveillance and fertility management techniques for males infected with COVID-19.