A couple who spent £64,000 on IVF treatment over ten years, despite being warned they had only a 5 per cent chance of conceiving, are finally celebrating the birth of a daughter.

In an IVF marathon thought to be one of the longest in Britain, Delina and Simon Tree finally conceived on their 15th attempt. Experts said their case was unusual, as most couples either conceive on the fifth or sixth attempt or give up soon afterwards.

The Trees, who are both 40, suffered a miscarriage, considered adoption, twice remortgaged their home and worked hundreds of hours of overtime in their struggle to become parents.

However, Mrs Tree, who gave birth to Olivia last month, yesterday said the heartache and hardship had been worthwhile. “We are so happy. All that time, effort and money was definitely worth it in the end.”

Mr Tree said he hoped that other couples were encouraged by their story. With each treatment costing about £4,000, Mrs Tree, a bank clerk, told how she and her husband, a carpenter, felt like they were “pouring money down the drain” each time they were unsuccessful.

“We have had to remortgage the house twice, take out loans and asked our parents to help us financially,” she said. “I stayed in a job I hated as a cashier manager at the Abbey and Simon worked evenings and weekends just so we had enough money for the IVF.” Mrs Tree, who turned to IVF after a natural pregnancy went wrong and she had a Fallopian tube removed, was examined by dozens of consultants across the country. None could explain why eggs removed from her womb to be fertilised had not developed once they had been put back.

Two years ago she was told by an expert at Oxford’s John Radcliffe Hospital that she had only a 5 per cent chance of conception due to the numerous previous attempts. She said: “Each time I had the IVF treatment I couldn’t relax. On one occasion I fell pregnant but miscarried very early on. It was heartbreaking.”

At one point the couple, of Sevenoaks in Kent, considered adoption, but backed out when they found the interviews too harrowing. Mrs Tree was encouraged by their family GP to begin a 15th IVF cycle. It was successful and Olivia was delivered by Caesarean on January 15. “For the first four months I was terrified. When friends congratulated me it didn’t sink in. I would even go for extra private scans to make sure that the baby was OK.”

Professor Stuart Campbell, former head of obstetrics and gynaecology at St George’s Hospital in London, described Mrs Tree as “very plucky”, as the average woman got pregnant on IVF after five or six attempts.

“Many fertility experts would want to call it a day before it reached double figures,” he said. “There has been a huge psychological toll for the patient as well as the financial burden. What would worry me is the assault on her womb and ovaries from so many cycles of treatment using steroids and hormones.”

Dr Geeta Nargund, a fertility consultant at Create Health in Central London, said that the health issues for women who had so many attempts were unknown, although it was clearly an emotional rollercoaster. “You have to admire her for going on so long. To put yourself through it so many times is amazing.”

About 30,000 women in the UK turn to IVF each year. Latest figures show a 6 per cent increase in the number undertaking treatment.

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