Couples undergoing IVF treatment should make sure that the man and the woman are taking good care of their fertility.
According to Zita West, fertility and pregnancy expert and founder of the Zita West Clinic, a lot of the focus is on the woman to be fertile.
However, "50 per cent is the man" so it is important for men to take care of their sperm.
Ms West added: "Especially when you are going through IVF, and ICSI - where they inject the egg into the sperm, it's almost like: 'We only need one sperm so it doesn't matter' but it does matter."
She explained that cycling and saunas can kill off sperm because of the heat they generate, which can be damaging.
Infections, weight and processed food can also have a negative impact.
The healthcare expert remarked: "So look at the factors in your life that may be having an impact on your fertility."