If there is magic on this planet, it has been said it is contained in water. I've always had that inkling and now that I'm on the countdown to our little one arriving into the world, I'm absolutely sure.

That magical element is palpable each time I go to an aqua-natal class. For those unfamiliar with aqua natal, it involves exercises specifically designed for pregnant women from 20 weeks onwards that are carried out in water and are usually guided by a physiotherapist.

In Ireland there are only a few such classes. One is run by Aileen Convery in Dublin at both the National Aquatic Centre in Abbotstown and in Mespil Swimming Pool in Ballsbridge.

"The beauty of aqua natal classes for pregnant women is the sense of weightlessness they feel. On land they can feel heavy and awkward, but in water they feel they can do anything. When water is up to their chest bones, pregnant women are 25pc of their normal weight.

"As a result, they are able to move gracefully and more easily build the stamina they will need in labour," says the former Olympic swimmer, chartered physiotherapist and mother-of-three. "In class we do exercises tailor-made to be safe for pregnant women in the second half of their pregnancy right up to the birth and they involve gentle fitness training and oblique cross-body exercises.

"These exercises are important because they are working the muscles, both internal and external, that support the bump and do the chief amount of work in the second stage of labour."

Now that I know what's ahead of me, I'm more than content to prepare my body. I join about 17 other women and their bumps in Aileen's class. We introduce ourselves, saying how many weeks on we are and where we will be giving birth.

Then, for the next hour, I wallow in the water, not feeling like a beached whale -- instead I am buoyant. I follow Aileen, who is also immersed in the pool, and work with the water to release tension, build upper and lower body strength (sometimes with the aid of polystyrene floats) and work specific areas such as the sacro-iliac joint at the base of the spine.

Needless to say, any pregnancy class worth its salt would not be complete without the pelvic floor exercises essential for a woman's post-baby quality of life, dignity and to prevent prolapse as time goes on.

"It takes roughly 1,000 repetitions for the body to lay down a muscle/nerve pathway that starts to become automatic. This is like learning to drive a car, it takes repetition to develop a somewhat automatic body action, where you don't have to tell yourself 'depress the clutch', 'change the gear', or 'push the accelerator' while doing it. If you can get the pelvic floor to this stage before having a baby, life is much easier afterwards."

So, in time with our breathing, rather than holding the breath, temptating when holding everything in, we practise fast and slow. At another aqua-natal class on Merrion Road, Co Dublin, run by physiotherapist Mary O'Driscoll, the focus is similar, but the atmosphere different -- it's almost a celebration of a very special and brief time in your life to be savoured.

With the pool to ourselves, there is a serenity present. Leaving work, worries and life in general outside, in the water it is about us and our babies. After all the hard work of stretches, strengthening, learning breathing techniques and stamina-building, we spend time with eyes closed and Mozart playing in the background gently massaging our babies, imagining how they look.

When I feel the first contractions, I'm pretty sure Mary's melodious New Zealand accent will be with me: "When you go into labour for real, relax and keep your head, have a cup of tea and go about your day knowing there are changes taking place in your body."

Verdict: Aqua-natal classes, especially as pregnancy advances, for me are heaven-sent. The feeling of weightlessness combined with stamina-building is both relaxing and empowering. A wonderful way to prepare.