17 Aug Does COVID19 pose a threat to male fertility?

SARS-CoV-2 and COVID-19 are entities with massive population involvement and high transmissibility, which have led to an unprecedented public health emergency in an extremely short evolution time. Despite the enormous spread and the scale of the impact, there is very limited knowledge about the adverse effects that SARS-CoV-2 may have on male reproductive health, both in the short and long term.

Viral infection has a disease incubation period of five days on average (between 2 and 14 days). In the course of the disease, a first phase of viral response of the infection has been described, followed by a phase of hyperinflammatory response. The predominant clinical manifestations are respiratory, although multiple organ and system involvement has been observed, including clinical manifestations compatible with orchitis (testicular inflammation).

The presence of the ACE2 enzyme may be a major determinant of the susceptibility of cells to SARS-CoV-2 infection and the gateway for the virus to enter the cell. ACE2 is expressed in different human tissues such as the lungs, kidneys, brain, vascular endothelium and especially the small intestine and testicles. So while it makes sense that the focus should rightly be on the vital organ systems (lung, kidney and heart), which are vulnerable to viral attack and contribute to the acute pathology associated with this disease, we should not lose sight of the fact that COVID-19 will attack any cell type in the body that expresses CEA2, including human sperm.

A similar percentage of sperm-producing testicular cells as lung cells have been shown to be directly involved in the pathogenesis of COVI-19. It also appears that ACE2 expression in the testicles is inversely proportional to the age of the male; thus, the maximum level of ACE2 expression would be recorded in individuals aged 30 years, which would make them more susceptible to the effects of SARS-CoV-2, constituting an obvious threat to their fertility.

At Reproclinic we have observed several young men who, after passing COVID-19 with no apparent general symptoms and no genital manifestations, have presented a considerable reduction in sperm count. At the moment, we cannot establish a pattern, nor do we know why it affects some men and not others. What we can say is that the ACE2 enzyme appears to play a key role in sperm formation, as testicular levels of this enzyme are significantly lower in men with severe alterations in sperm production than in those with normal sperm formation. It has also been observed that male sex hormones decrease in patients with COVID-19 at the time of admission to the ICU, with low levels of testosterone and dihydrotestosterone. However, this phenomenon could be more related to the stress caused by the situation or to other symptoms linked to the infection itself.

Is this decrease in sperm production a transitory and therefore reversible phenomenon?

We cannot say yet. We are waiting for the results of our patients and of the studies that are being carried out in other reproduction centres in the world, in order to be able to evaluate the recovery capacity of the testicles in the face of the impact of the SARS-CoV-2 virus. We do not know when and to what extent they will recover their sperm function.

If we have evidence that COVID-19 can alter sperm production, how should we proceed?

This is not a situation that should cause alarm, although, if you are a male of childbearing age and have passed COVID-19, we would recommend you to:

• Have a semen analysis (evaluation of the number and quality of spermatozoa).
• Visit an andrologist. His advice on lifestyle, diet and treatment can speed up recovery.

If you have not yet passed COVID-19, why not freeze your sperm?

Preserving your fertility will ensure that you will be able to have offspring regardless of whether you experience a decrease in sperm production later in life, whether due to COVID-19 or another health problem. In the world of fertility, prevention is a good strategy.

Currently, we do not know the real impact and reproductive consequences of SARS-CoV-2 infection in the young male. However, we must highlight the evidence that the male reproductive system is a vulnerable target for infection by the virus and, therefore, we must remain vigilant to the possibility that it may induce alterations in male fertility, leading to a decrease, reversible or not, in sperm production.