Impact of COVID-19 on sperm quality

By Tarun Sai LomteDec 1 2022Reviewed by Aimee Molineux

In a recent study published in the Journal of Medical Virology, researchers examined the effect of coronavirus disease 2019 (COVID-19) on sperm quality.

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection typically causes respiratory symptoms and fever, but in some cases, COVID-19 may be severe with multi-organ involvement. The host cell receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), is widely expressed in the lungs and spermatogonia, Sertoli cells, and Leydig cells.

It has been suggested that gonadal functions may be affected due to inflammatory responses against SARS-CoV-2. Moreover, immune responses in the testes negatively impact spermatogenesis. Therefore, more research is required to understand the effects of SARS-CoV-2 infection on the male reproductive system.

About the study

In the present study, researchers evaluated the impact of COVID-19 on sperm morphology, motility, and count. Males aged 20 to 50 years visiting the in vitro fertilization (IVF) unit at the Adana City Training and Research Hospital were included. Males who tested SARS-CoV-2-positive in the past three months and those with less than 1.5 ml of semen were excluded.

Participants with a confirmed history of SARS-CoV-2 infection in the past four months to one year were included in the COVID-19-positive group, and those without COVID-19 served as controls. There was no information on whether participants underwent a spermiogram before COVID-19. Samples were not obtained from those with severe COVID-19.

Sperms were enumerated under a phase contrast microscope and were classified as types a (rapid progressively motile), b (slow progressively motile), c (motile in situ), or d (immotile). The proportion of each sperm type and total motility were determined. Samples with a concentration of more than 5 x 10⁶/ml were stained and examined per the Kruger criteria.

Findings

Overall, 200 males were included in the study, equally split into COVID-19-positive and -negative cohorts. Of the SARS-CoV-2-positive males, 48 had a mild clinical course, and 52 developed moderate symptoms. The median age was 30 and 30.5 years for COVID-19-negative and -positive participants, respectively. The median sexual abstinence period was four days for COVID-19-negative males and three days for those in the COVID-19-positive group.

The sperm concentration of COVID-19-negative participants was significantly higher than COVID-19-positive males. Nevertheless, semen volume and sperm morphology, and motility did not significantly differ between the two groups. Four males in the COVID-19-positive group, but none in the COVID-19-negative cohort, had azoospermia. 

Conclusions

To summarize, the researchers observed significantly elevated sperm concentrations in males without COVID-19 infection relative to those who had been COVID-19-positive. No significant differences were observed in sperm motility or morphology between the two cohorts. However, azoospermia was detected in four SARS-CoV-2-positive males.

Since prior spermiogram data were lacking, it could not be ascertained whether azoospermia was due to COVID-19. Although some studies support the negative impact of COVID-19 on male reproduction, they are limited by small sample sizes. Therefore, longitudinal studies with extensive sample sizes and pre- and post-COVID-19 data may better assess the impact of the disease on sperm parameters.