COVID impacts male fertility

COVID has affects beyond the lungs...
02 February 2021

Interview with 

Bill Colledge, University of Cambridge


The new coronavirus that causes COVID-19 is a respiratory infection. But that doesn't mean the effects of the virus are confined solely to the nose, throat and lungs. Indeed a study from researchers in Germany this week, looking at men who caught COVID in Iran, has found that the infection can have long term effects on fertility. The study found that sperm counts drop and there are signs of persistent inflammatory changes in the male genital tract. Chris Smith spoke about this with Bill Colledge, who is a male reproductive physiologist at Cambridge University commenting on the paper just out in the journal Reproduction, from Justus-Liebig University...

Bill - This is a really fascinating study. Scientists have looked at the fertility of individuals in Iran to see what effect the COVID-19 virus might have on their reproductive parameters. They actually studied a group of 84 males that were recovering from a COVID infection and they compared that group to 105 healthy age matched individuals that didn't have a COVID infection and they looked at a variety of different factors. Including substances normally found in semen and they also measured indicators of fertility, such as the number of sperm and the motility of the sperm.

Chris - How often did they look at these people?

Bill - They looked every 10 days or so after they'd got over the viral infection and they looked out to about 60 days.

Chris - And were all of the people equivalently unwell with these all hospitalised patients, or were they people with mild illness?

Bill - They all had the virus. Some of them were sort of milder symptoms than others. Some of them were more severe. Some of them had to be hospitalised, but the point is that when they were looking at these individuals, they had got over the viral infection. So they're looking at what the impact might be after the viral infection, rather than during the virus.

Chris - So what did they actually find then when they followed them up both at short time points compared with, you know, as time went on, what did they see?

Bill - They looked for substances in the semen and they found an increased level of these specific factors, which are called interleukins, that modulate activity of the immune system. They also looked at the number of sperm and the motility of the sperm, and they found that these were compromised in the individuals that had had the virus.

Chris - And did they stay compromised because that's a critical thing, isn't it? You could argue, well, you've just been very unwell. It's possible that that's the cause of having a lower level of some of these markers of fertility in the short term but what happens if you, if you look at longer time points, did it bounce back?

Bill - Well, I mean, the real surprise with this study is that these individuals had compromised fertility out to about 60 days after they had the infection. So up to two months later. There was a suggestion that they were starting to recover, but even at two months they still had problems with sperm counts and the production of these interleukins. I suspect that in a longer timeframe they'll probably get better, but it does illustrate that you get the viral infection you recover, but you can still have some health issues that can go out up to two months.

Chris - And presumably, although they've got sort of markers that we know go along with a person having a lower level of fertility, they haven't followed this through and said, and now we've tested to show these people really are suffering from lower fertility.

Bill - No, they certainly haven't. So they've got lower sperm counts, but they haven't shown whether that affects fertility. So they don't know whether it would affect the ability of that individual to have a child. They also haven't done any direct look at the testes in terms of its structure. They've just looked at the parameters in the semen. So they don't really know what's going on within the testes.

Chris - Is there any risk that it could do damage to the DNA in the sperm, in such a way that, that people could have babies with genetic problems in the aftermath of the father having what might amount to infection with Coronavirus in the testes?

Bill - There is a suggestion in this paper that they have found there could be damage to the DNA within the sperm. Hopefully, that will only be a short term effect and the beauty of the testes is that it has a population of cells which can divide and replenish to produce more sperm as long as there's no damage to that population of stem cells. Then the individual should be okay and should be able to make normal sperm later.

Chris - So should people then do you think as a cautionary note, avoid trying for a baby, if they're in the immediate aftermath of COVID infection?

Bill - Well, there's a risk. If you have a COVID infection and it's affecting the quality of your sperm, you may want to perhaps not try and have a baby. It might be sensible to wait a few months.

Chris - And do women have anything to worry about?

Bill - There's no indication that women have anything to worry about. The process of sperm formation and egg formation is significantly different. Hopefully it wouldn't cause a similar effect, but again, that study hasn't been done.


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