From Kate Middleton to Kim Kardashian, pictured, lots of high-profile women are with child.

Dublin - Many newspapers over the New Year period spent time predicting the trends of 2013. A theme that raised its head in virtually every one I read was that 2013 is going to be the year of the celebrity baby. From Kate Middleton to Kim Kardashian, lots of high-profile women are with child.

Despite all the talk of babies though, humans are estimated to be one of the least fertile species on earth with, on average, a 20 percent chance of conception with each fertile cycle.

For one in six couples, achieving that much-wanted pregnancy can be a stressful and heart-rending journey. Predicting and assisting fertility becomes a crusade for many would-be parents.

A report released in 2010 looked at the difference between index and ring-finger length in men, stating that those who have a lower index/ ring-finger ratio were more likely to be infertile. I wonder, did a lot of women check out the fingers of their partner after reading that one?

We know that when infertility occurs, about one-third of the causes are female, another third male and yet another third due to no apparent cause.

So how can the average person improve their fertility?

It may seem like stating the obvious, but having regular unprotected intercourse is essential to maximise chances of conception.

Having sex every day, however, is not recommended. Sperm can live for up to 72 hours in the female genital tract but take up to 24 hours to regenerate, so intercourse every two to three days all month provides the greatest chance of conception.

Ovulation kits are not recommended, especially as they can add a lot of stress to the whole process which in itself can throw off fertility.

The biological clock is unfortunately a real phenomenon. A woman’s fertility peaks in her 20s, starts to wane in her 30s and declines rapidly over the age of 40.

Women are born with all the eggs they will ever have, but only about 12 percent remain by the age of 30. However, only 20-25 percent sperm actually swim in the right direction!

Up to 80 percent of couples conceive within a year of unprotected intercourse.

Nearly everyone knows someone who either conceived in the first month of trying or has had fertility problems, so many prospective parents panic if they haven't conceived within a few months.

Investigations are not actually advised until you have been trying for a year under the age of 35 or for six months over this age. At that point a simple visit to the GP can help identify potential problems or do a lot to reassure a couple the odds are in their favour. Further investigations often involve referral to a fertility clinic.

The pregnancy rate with assisted fertility is about 28 percent per cycle, but varies according to clinic, maternal age and other factors.

Lifestyle is one way which we know that people can maximise fertility. Smoking and using narcotics reduces fertility in both sexes, as does excess alcohol consumption. Being over or underweight also affects fertility, so try to keep your BMI between 20 and 25. Eat well, reduce stress and avoid cigarettes and regular alcohol. It’s the ultimate detox!

So those of you hoping to conceive in 2013, check out your man’s hand – you know you want to!

Then digest the advice above and make it part of your lifestyle for the year ahead. Most of all, have fun trying. – Irish Independent

* Dr Nina Byrnes is the author of “Your Health Matters”