It's Men's Health Week. Here's what scientists want you to know about sperm and male infertility.

Dr Nicole McPherson is the Director of Research and Science Education at Genea but is also a reproductive health expert who studies sperm. We recently sat down with Nicole as part of our Mens Health Week chats to ask the questions on your mind.

How long does it take for one sperm to be made?

It takes approximately 2 months for one sperm to be made in the testes (~64 days). Men are continuously making sperm from puberty until death. 

Q. What are some of the most interesting facts about sperm?

Sperm are some of the most unique cells that make up men.

1. The obvious one is that they are the only cell that can swim/propel themselves to a target.

2. They can live in the female reproductive tract for up to 5-7 days post ejaculation waiting to fertilise the egg.

3. It only takes then 15-60 min post ejaculation to reach the site of fertilisation.

4. Humans have the worst sperm of any mammalian species and only require 4% to look normal to be classified as fertile compared with other primates and large animals who have between 60-80% normal looking sperm.

5. For a really long time before modern science, it was believed that sperm carried a tiny little baby in their head and delivered it to the uterus.

   
   

Q. How can someone find out if their sperm are fertile?

A semen analysis is the easiest way to find out the health of your sperm. A semen analysis looks at the amount of sperm (count), what they look like (morphology) and how they move (motility). While having an abnormal semen analysis doesn’t necessarily mean that you will have trouble conceiving, it can be a useful tool to determine a potential reason in those couples who have yet to fall pregnant.

Q. Are there any myths that you would like to debunk?

Yes – that infertility is a female problem. This is just not the case. Defective sperm function makes up 50% of reasons why couples can not fall pregnant (30% sole reason and another 20% as a contributing reason). 

But the best thing about sperm is, because they are being made continuously and are responsive to their environment, men have a fantastic opportunity to potentially intervene and improve their fertility. 

Q. We continuously hear about sperm DNA damage being factor for male infertility – can you expand on this?

The quality of the sperm DNA (male genetic component deliver at conception) is hugely important for the success of getting pregnant, and recent evidence has suggested is the largest contributing factor for early miscarriage.

The quality of sperm DNA can be tested for in the Andrology laboratory by the sperm DNA integrity assay, which can be a useful tool for further understanding why someone might be having trouble getting pregnant or staying pregnant even if their semen analysis is normal.

But the best thing about damage to sperm DNA is that simple changes to one’s lifestyle can have a profound impact. 

Q. You talk about simple changes to one’s lifestyle can have a profound impact on sperm health – can you elaborate more?

Sure – the best things that men can do to improve the health of their sperm are the same things that people can do to improve their overall health, although there are some sperm specific tips:

1. Eat a nutrient-rich diet low in fat and sugar 

2. Try to exercise at a light to moderate intensity about 150 minutes per week 

3. Try to reduce or quit smoking 

4. Reduce your alcohol consumption  

5. Reduce recreational drug use 

6. Reduce exposures to toxic chemicals, micro plastics and pollutants 

7. Be aware of influential factors sometime outside of your control (i.e. age and genetic disorders) 

8. Frequent ejaculation every two to five days. 

   
   

 Q. We keep hearing about a men’s sense of masculinity been tightly linked to their fertility – can you expand more on this?

Yes, you are correct. Male fertility is hugely wrapped up in how men feel about their sense of self and ‘what it is to be a man’. As such a diagnosis of male infertility can be deeply impactful and a direct threat to their sense of masculinity. As such extreme care should be taken when delivering a male infertility diagnosis as well as offers for support post diagnosis and during treatment.

Q. Is it true that sperm can act like a ‘canary in the coal mine’ for men’s overall health?

Poor sperm health can sometimes indicate a bigger problem. For instance, many factors that contribute to poor sperm function such as genetic and lifestyle factors are all so associated with several chronic diseases such as cardiovascular disease and metabolic and autoimmune diseases. As such poor sperm health can be an indictor of another health problem. 

Q. We hear that female fertility declines with age. Is it the same for men?

Although men do not experience as rapid a decline in fertility as women, research indicates that changes in male fertility can be observed from the age of 40 onwards. For example, men aged 40 and above have a reduced likelihood of conceiving within a year compared to their younger counterparts. Additionally, older men are more prone to having higher rates of genetic mutations in their sperm, which has been linked to a slight yet noteworthy increase in the risk of birth defects and neurodevelopmental disorders like autism in their children.

If you're trying for a family, take the first step to get tested this Men's Health Week.

Book your Fertility Health Check with the Fertility SA team here.