If you're trying for a baby, your partner's fashion choices could make a difference. Specifically, his choice in undies.

Recent research from the Harvard T.H. Chan School of Public Health in Boston has shown that men who wear boxers have higher sperm concentrations than men who wear tighter-fitting undies.

The study analysed 656 men from couples seeking infertility treatment aged between 18 and 56. They answered a questionnaire about the types of underwear they'd worn in the last three months and also provided researchers with a semen sample and a blood sample on the same day.

Not only did the men who wore boxers have a 25 per cent higher sperm concentration, but they also had a higher total sperm count, more swimming sperm in a single ejaculate and they were the correct shape. Time to throw out the tighty whities, lads.

Boxers versus briefs, which is better for male sperm?

How to boost male fertility

So now you've invested in some boxer shorts, what are some other ways your man can increase his fertility? Apart from wearing loose-fitting underwear, Professor Kerryn Phelps has some tips to help increase sperm count.

  • Quit smoking tobacco or cannabis. While smoking lowers sperm count and reduces sperm motility, cannabis lowers sperm count and increases the number of abnormal forms.

  • Avoid alcohol as it can reduce the sperm count, plus it increases the numbers of abnormal sperm.

  • Get into a healthy weight range.

  • Up your oily fish intake or try a fish oil supplement for a boost in sperm count.

  • Avoid processed meats as they reduce sperm quality.

Hot baths aren't great for healthy sperm. Oh well, more for us girls!

  • Stay away from anabolic steroid injections as they shrink testes and reduce fertility.

  • Take supplements for zinc, vitamin C and other micronutrients, such as selenium, folate and magnesium, that are also essential for optimal fertility.

  • Eat a balanced diet and opt for organic foods and products whenever you can.

  • Exercise regularly, but don't overdo it.

  • Stay out of the sauna and hot tubs to avoid heat stress.