Kan mandlige fertilitetsproblemer gå i arv? 

As parents, you might hope that you pass on some of your more favoured genetics to your children – may be your aptitude for running or your thick head of hair. But what if you are concerned about passing on things you’d rather not, like issues with fertility?

In this blog, we’ll take a look at the latest research into this topic and explain how certain factors of infertility could be passed on to your children – directly or indirectly. 

Can male fertility issues be inherited? What the science says.

Whilst studies into the hereditary nature of infertility are still ongoing, it’s worth examining the current research to understand the known risks of passing fertility issues on to our kids – more specifically our sons. 

I en recent Danish study, the results indicated that there was no obvious link between the subfertility of parents and the sperm health of their sons. The study recruited 1058 young men whose mothers were on a public database that held information about the conception and pregnancy of their children – including whether they received any fertility treatment. The men joining the study were split into categories connected to their conception; this ranged from unplanned pregnancy and naturally conceived under 6 months of trying, to conception following IVF or intracytoplasmic sperm injection (ICSI).

The men provided blood and semen samples for analysis – and factors including sperm volume, concentration, motility and morphology were investigated. The study found ‘no major differences in the sperm health and quality of the men that had been conceived through assisted fertility treatment’ – and any correlation they did find was pretty insignificant. 

This latest piece of research does seem to contradict earlier studies that indicated infertility could be passed down. One undersøgelse found that boys who had been conceived through ICSI were more likely to have poor sperm quality – lower sperm count and motility – compared to those who had been conceived naturally. However, this study only analysed 113 men – so we will need more studies before we can conclude on this relationship.

Passing on genetic conditions

Whilst the research seems to indicate that male factor infertility isn’t hereditary, there are genetic conditions that are linked to infertility, some of which can be passed down from parents to children. 

Cystisk fibrose og mandlig fertilitet 

Cystic Fibrosis is a condition that can be passed on from parents to children – and one that has links to infertility 

Cystic Fibrosis (CF) is a genetic condition and is caused by a faulty gene that affects the movement of salt and water in the body. This causes sticky mucus to build up in the lungs and digestive system, which is why problems with breathing and eating are some of the most common symptoms in people with CF. But what’s that got to do with male fertility? 

Well, another symptom of CF in men is not having a vas deferens – the tube that essentially allows sperm cells to become part of semen. Whilst the vast majority of men with Cystic Fibrosis can produce healthy sperm, they won’t be able to conceive naturally as there will be no sperm cells in their semen. However, through an operation called testicular sperm extraction (TESE) it’s possible to extract healthy sperm cells and use them in IVF – so having Cystic Fibrosis does not necessarily stop you from having biological children! 

Cystic Fibrosis can be passed on through parents that have CF themselves, or if both parents are carriers of the faulty gene. It’s estimated that around 1 in 25 people in the UK are carriers of the CF gene. 

If you have Cystic Fibrosis it’s understandable that you may be concerned about passing both the condition and the chance of infertility down to your children. However, if you decide to go down the route of IVF, it’s possible to genetically test viable embryos before implantation to check if they have CF. 

Kartagener Syndrome and Male Fertility 

Kartagener syndrome is a rare genetic condition which impacts the cilia – tiny hair-like structures within our cells. The condition causes abnormalities in your respiratory tract known as primary ciliary dyskinesia (PCD) – which triggers symptoms like chronic breathing problems –  and can also cause issues with fertility.  

Much like the respiratory tract, the epidermis (a collection of tubes where your sperm is stored) is also lined with cilia-like structures to help cells move. As PCD impacts these structures, it can make the epidermis a tough environment for sperm cells to thrive. Another factor that impacts male fertility is that sperm tails have a very similar make-up to cilia. In men with Kartagener Syndrome, it’s very common to see sperm cells that struggle to swim – and have very low motility. Around 75% of men with Kartagener’s syndrome struggle with fertility issues. 

Like Cystic Fibrosis, Kartagener Syndrome can be passed on from parents to children, and you and your partner would both have to carry the gene mutation for your child to end up with the condition. 

Klinefelter Syndrome and Male Fertility 

Klinefelter’s Syndrome is a genetic condition, in which a boy is born with an extra X chromosome. As men are usually born with XY chromosomes, this random genetic mix-up can have a massive impact on a man’s testosterone levels and sperm production – and cause infertility.  

However, unlike Cystic Fibrosis, there is no evidence to suggest that Klinefelter Syndrome is passed on through families, despite the fact it’s a genetic condition. Whilst it is quite rare for men with Klinefelter Syndrome to be able to conceive naturally, if you have Klinefelter syndrome and conceive using your own sperm, it’s not more likely that your son will have the same condition. 

Read our article on Klinefelter Syndrome for at få mere at vide.

Passing on lifestyle factors 

Of course, aside from genetic factors, there are a lot of lifestyle factors that can trigger male subfertility. 

Whilst there is still more we have to learn about the hereditary nature of male infertility, there is plenty of research into how our habits and lifestyle impact those of our children. 

For example, children whose parents smoke are more likely to become smokers themselves. Smoking is one of the worst things you can do for your fertility, so whilst you might not be directly passing on fertility issues to your kids, passing on a habit of smoking cigarettes could indirectly have an impact on their future sperm health. 

Likewise, children whose parents are overweight or obese are more likely to also have an unhealthy weight as adults. BMI is another really important factor when it comes to male fertility and maintaining a healthy weight through diet and exercise has been linked to improved sperm health. 

If you are planning on becoming a father, addressing these lifestyle issues will not only mean you are less likely to pass these habits on to your kids – but it will also help to improve your own fertility and health. 

Read more about healthy lifestyle habits to improve your sperm health her. 

In conclusion, unless you have a specific genetic (and hereditary) condition that is impacting your fertility, the chances of passing on subfertility are low. However, understanding the root of your fertility issues will help you ensure that you are doing everything you can to improve your sperm health and protect the fertility of your future children. 

Testing your sperm is a great first step in getting to know your body better. Click the link to learn more about our sædprøve i hjemmet.