The ability of sperm to move and fertilize eggs has a normal rate of 50%. Among men who were infected by the new coronavirus and developed Covid-19, however, this sperm motility is reduced to levels between 8% and 12%, according to studies conducted at the University of São Paulo.
Even a year after the disease, previously infected men maintained this low motility. Another change noticed was related to hormone levels. Although the normal level of testosterone in men is 300 to 500 nanograms per deciliter of blood (ng/dL), among men who had Covid-19, the hormone reached values ??below 200 and often between 70 to 80 ng/dL.
According to Jorge Hallak, a professor at the USP School of Medicine, and one of the researchers, they have increasingly seen prolonged changes in the quality of the semen and hormones of patients who had Covid-19. “(…) even in those who presented a mild or asymptomatic condition”, explains Hallak, in an interview with Agência FAPESP.
Testicles and epididymis
Studies conducted in collaboration with the Faculty’s Department of Pathology revealed that SARS-CoV-2 is capable of infecting the testes as well. As a result, they impair the ability of the male gonads to produce sperm and hormones.
According to Hallak, this happens even in asymptomatic cases or with few symptoms. “Among all the agents harmful to the testicles that I have studied so far, SARS-CoV-2 seems to be very active”, he highlights.
“Each pathology has particularities that practice and experience show us. SARS-CoV-2 has the characteristic of affecting spermatogenesis in ways that we are discovering now, such as persistently very low progressive motility, without significant change in sperm concentration”, explains Hallak to the FAPESP Agency.
The results came from an analysis of 26 patients who underwent Covid-19. From ultrasound examinations, the researchers found that more than half had severe inflammation of the epididymis, the structure that is responsible for storing sperm, in which they acquire the ability to move. The findings were published in the scientific journal Andrology.
“Unlike a classic bacterial infection or by other viruses, such as mumps, which causes swelling and pain in the testicles in one third of those affected, epididymitis caused by the new coronavirus is painless and cannot be diagnosed by palpation. [exame físico] or with the naked eye,” warns Hallak.
During the consultation, the following should be evaluated:
- Testicular volume measurement;
- Testosterone and other hormones dosage;
- Semen analysis with sperm function tests;
- Color Doppler ultrasound examination to assess for possible testicular involvement that could affect fertility and hormone production.
“These individuals should be followed up for at least one to two years after infection, as we still don’t know how the disease progresses,” explains Hallak.
Coronaviruses in testis cells
The same group of researchers also developed another study, published in the same scientific journal, which indicates that the new coronavirus is capable of invading all types of cells in the testis. This invasion can impair hormonal function and male fertility.
To arrive at the results, the researchers used minimally invasive autopsy techniques to take testicular tissue samples from 11 men, aged between 32 and 88 years, who died from severe Covid-19.
In an interview with Agência FAPESP, Amaro Nunes Duarte Neto, an infectious disease specialist and pathologist at FM-USP and the Adolfo Lutz Institute, and coordinator of the study, highlights that, even in younger patients, the amount of sperm was quite limited. “What immediately caught our attention in these patients who died from Covid-19 was the drastic decrease in spermatogenesis. Even the youngest, of childbearing age, had practically no sperm”, she explains.