Sars-CoV-2 infection could damage male fertility, even in the long term. So it follows from a spanish study presented at the Annual Congress of the European Society for Human Reproduction and Embryology (Eshre), held in Copenhagen (Denmark).
Specifically, the study shows that, after at least 100 days after having tested negative for Covid 19 in men, there is no improvement in the number and motility of spermatozoa, even though new sperm have been produced during this time.
Between February 2020 and October 2022, the researchers recruited 45 men (with a mean age of 31 years) in six Spanish reproduction clinics. All had a confirmed diagnosis of mild Covid. In the centers they had collected semen samples before infection and then another sample was taken between 17 and 516 days later to have overcome it. The comparison showed a statistically significant difference in sperm volume (-20%, from 2.5 to 2 milliliters), sperm concentration (-26.5%, from 68 to 50 million per ml), sperm count ( -37.5%, from 160 to 100 million/ml), total motility (-9.1%, from 49% to 45%), and the proportion of live sperm (-5%, from 80% to 76%) . After Covid, half of the patients had an average sperm count 57% lower than before infection. And not only that: one hundred days after the infection (more than three months), concentration and mobility had not improved.
Thus, the Covid, even if contracted slightly, seems to worsen the quality of sperm in the long term, although it is still any impact on fertility remains to be clarified. Based on previous work that showed how the quality of male sperm seems to deteriorate in the short term after infection by Covid, Rocío Núñez-Calonge, scientific adviser to the Ur International Group of the Madrid Scientific Reproduction Unit, wanted to investigate the duration of the damage. “Considering that it takes about 78 days to produce new sperm, we found it appropriate to assess its quality at least three months after recovery from Covid“, explained the expert. “We assumed that it would improve, but it has not been like that. We don’t know how long it may take to recover pre-infection sperm quality, and permanent damage cannot be excluded even in men who have had a mild form of Covid.”
Núñez-Calonge pointed out that the deterioration in sperm quality may not be due to a direct effect of Sars-CoV-2. “It is likely that other factors, currently unknown, contribute to the long-term deterioration of these parameters,” she explained. “In this study we did not measure hormone levels: previously marked changes in testosterone have been reporteda key factor in male reproductive health, in patients with Covid infection”. For Núñez-Calonge, “it is especially interesting that this decrease in sperm quality occurs in patients with mild infection, which means that Sars-CoV -2 could affect male fertility even in the absence of clinical symptoms of the disease.”