IT'S something most couples take for granted. But when baby Archie arrived, parents John and Paula Swinscoe could have been forgiven for being more overjoyed than most.

Weighing in at exactly 6lb, Archie's birth came as a shock to the couple, of Fellstone Vale, Withnell, near Blackburn - not least because they once faced the bleak prospect of life without any children at all.

After seven difficult years spent trying for a baby, Paula was eventually able to give birth to Jack and his little brother Arran thanks to IVF (in vitro fertilisation) treatment.

But in becoming parents to their third son Archie, John and Paula became one among approximately two per cent of couples to conceive naturally after taking the IVF route.

Paula, 34, discovered she was expecting Archie just five months after giving birth to Arran.

"Archie was a real shock," she said. "We just couldn't believe it - we were thrilled.

"But we think really it probably wouldn't have happened if I hadn't had the other two through IVF.

"It seems that can kick start things and get the hormones going. The idea we've made him ourselves is very odd. Having children the normal way is a bit foreign to us!"

At the age of 23 Paula was bluntly informed by doctors she faced the prospect of infertility.

Paula and John, a well-known East Lancashire rally driver with his own engineering business - RallyTech - decided to try for children immediately, but were hampered by Paula's condition. After years of continuous tests, the couple were referred to St Mary's NHS Hospital in Manchester for IVF treatment. However, they were devastated to learn the waiting list was three years.

Desperately seeking another solution, John and Paula went to a private fertility treatment clinic based in Nottingham called CARE.

In July 1999 John and Paula begin their ICSI treatment - a pioneering form of IVF.

The couple then faced an agonising two-week wait to find out if the treatment had been successful. Amazingly, the treatment worked first time and Paula found she was pregnant with Jack.

The couple's first boy was born in April 2000 and, in March 2003, Paula gave birth to another boy, Arran, this time through normal IVF procedures.

With Archie's surprise arrival on the scene this year, Paula and John feel their family is complete.

But their happiness has come at the price of enormous psychological and emotional strain as well as a financial burden of nearly £6,000 for the IVF treatment. For many people IVF issues are a moral maze - from NHS treatment to "designer babies". But Paula believes the alternative - a childless future - can be equally difficult for outsiders to comprehend.

"So many people just accept the fact they can have children," she said.

"But it's difficult to understand infertility until you have been there.

"It's like having something taken away from you that you thought you had a right to expect.

"We dreamed of having these children. This is the perfect family for us."