The Effect of COVID-19 on Laboratory Parameters

Objective: This study aimed to investigate the long-term effects of coronavirus disease-2019 (COVID-19) on semen parameters and hormone levels by dividing the timeline into pre-pandemic, pandemic, and post-pandemic phases. Method: Between May 2017 and April 2024, we conducted a retrospective study including 10,082 semen analyses from 6.517 patients at our hospital. Patients were divided into three groups according to the World Health Organization (WHO)-defined pandemic start and end dates: pre-COVID-19 (May 2017-March 2020; n=2378), COVID-19 period (March 2020-May 2023; n=5568), and post-COVID-19 (May 2023-April 2024; n=2136). Semen analyses and hormone parameters [total testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and prolactin] were examined. However, it was not possible to determine whether each patient had been infected with COVID-19. All semen analyses were performed in accordance with WHO 2010 guidelines. Results: Sperm concentration, motility, and morphology significantly increased during and after the COVID-19 period compared with the pre-COVID-19 period (p<0.01). Semen volumes remained similar across all three periods (p>0.05). Testosterone levels also showed significant increases during and after the pandemic (p<0.01). In contrast, FSH and LH levels decreased significantly during and after COVID-19 (p<0.001). No significant changes were observed in estradiol levels, whereas prolactin levels increased during and after COVID-19 (p<0.001). Conclusion: COVID-19 was associated with notable changes in male reproductive health indicators; however, no permanent negative impact on male fertility was identified. Further prospective studies are needed to validate these findings and to elucidate the underlying mechanisms.