Men hoping to become daddies are sure to be thrilled at the latest news story which suggests that they have a better chance if they swap their daily Americano for a pint of beer.
hose who drank two or more cups of strong coffee a day had just a one-in-five chance of becoming fathers through IVF, according to the study which was carried out at Massachusetts General Hospital in Boston. It also shows that men who drink around a pint-and-a-half of beer a night could improve their fertility.
However, lead author, obstetrician Dr Anatte Karmon, advises that men should keep their lifestyle as healthy as possible if they were hoping to become fathers. And the same advice certainly applies to women.
Researchers now believe that stress levels and lifestyle factors prior to conception are just as significant to the health of a future baby as they are during pregnancy, says Sorcha Molloy, a nutritionist with Galway's Glenville Nutrition Clinic, who points out that low vitamin D in pregnancy is linked to a higher risk of diabetes and obesity in later life.
So, how can a woman protect her fertility?
Plan ahead and talk to your mother
"One of the biggest problems I see is that we don't engage in our fertility early enough and when we do, we're playing catch-up," says fertility specialist Emma Cannon, who has experienced this many times at her London clinic, The Fertility Rooms.
"Not every woman will be able to have a baby early in life, but you can still take steps to understand it and preserve your fertility. If you find a problem when you're 38, time erodes quite quickly. But if you knew earlier that you had endometriosis, you would have a plan in place. If you knew that your mother had had an early menopause, you would at least be aware of a potential difficulty."
Cut down your drinking
... but not too much. A Danish study has revealed that moderate drinkers who have about two glasses of wine a week conceive quicker than teetotallers, although Emma Cannon points out that the moderate drinkers may be having more sex. "In Chinese medicine, it is said that a little bit of alcohol increases the libido but a lot can damage it."
However, fertility expert Jessica Bourke, who is based in Dublin's Dun Laoghaire and has almost a decade of experience in reproductive health, takes a more absolutist approach, advising against alcohol completely. If you are going to indulge however, she recommends "no more than one drink per hour, making sure to drink water alongside it and never on an empty stomach". Sorcha Molloy says "alcohol depletes nutrients such as zinc and folic acid, and those who drink seven or more drinks a week are twice as likely not to conceive".
Forget the five-a-day, it's time to embrace seven-a-day, focussing on veggies, particularly of the dark-green leafy variety.
Emma Cannon says that we really need omega 3s in our diet and while there have been some concerns about mercury levels in fish, several studies demonstrate that the health benefits outweigh the mercury worries. She recommends smaller fish such as sardines and mackerel, rather than tuna and swordfish.
Not all protein has to come from meat, adds Jessica Bourke, who points out that the World Health Organisation has a 15pc daily cap (the equivalent of a small chicken breast) whereas in Ireland, most of us eat up to 45pc.
"Have a few veggie dinners or use substitutes such as a mixture of kidney beans and mince in chilli, and make sure to get lots of fibre in your diet from nuts and seeds, as well as wholegrains and high-protein grains such as quinoa."
It's not just a question of what you eat, but when you eat it.
"If you don't eat regularly, you risk your insulin levels spiking and sugar being released into the blood stream," says Jessica Bourke. "If you're under stress while you're eating, your body will not absorb the nutrients as it should and you have increased levels of blood sugar which affects the conversion of testosterone into oestrogen."
Say no to that second espresso
Caffeine may possibly impact men more than women, but it can be hard on women, too, as it's an anti-nutrient, says Sorcha Molloy, who adds that it is linked to increased risk of miscarriage and still birth.
And there's no point in just switching to decaf, as the chemicals used to strip the caffeine out are potentially more damaging than the caffeine itself, says Jessica Bourke. Better to have just the one cup of coffee at the weekend as a treat. Sorcha Molloy recommends swapping to herbal teas, Rooibos tea or barley and chicory drinks.
Watch your weight
Both being obese and underweight can impact on a woman's fertility. It is generally accepted that obesity is a problem but a BMI under 19 can also cause a problems for female fertility leading to amenorrhea (lack of periods) and subsequent lack of ovulation. Emma Cannon believes that fertility is not essential for our individual survival only to the survival of the species, fertility is probably a peripheral need for our bodies. "So if the body feels in danger or there's a dramatic weight loss or it's not getting enough calories, fertility is one of the first things to be compromised. Because many people are stressed, they are operating in fight or flight mode, which is really a survival mechanism for the body causing it to release adrenaline in order to run away from danger. This continued low-level stress can leave the body feeling it isn't safe to conceive or not the most optimal time."
We all know that exercise is important, and studies have shown that it regulates hormones and helps to burn off stress. But Jessica Bourke points out that the type of exercise counts, too. So skip hours on the treadmill for interval training. According to Jessica, working out for just 12-20 minutes three times a week has a definite improvement on hormone levels. She recommends the Tabata method of high intensity interval training.
And sleep well
Getting enough shut-eye is crucial for overall health, and numerous studies recommend that we get seven to nine hours. But if a woman is suffering from insomnia or falling asleep and waking around 3am, this suggests that her melatonin sleep hormone is likely to be too low at night-time when it should be at its highest. This implies there's a problem with her adrenal hormones, says Jessica Bourke..
And, finally, stop smoking
Experts agree that it's one of the worst things you can do. It's been found that women who smoke have a 30pc lower fertility rate compared with non-smokers. "There's a lot more evidence against smoking than alcohol," says Emma Cannon.
Emma Cannon's new e book 'Fertility to Family' will be available on October 31