Fidelma and Paul Greene, from Swords, Dublin, said yesterday their daughters, Lauren and Sophie, were thriving three months after being born.

Their unborn children had been given almost no chance of survival when Rotunda Hospital medics discovered they suffered from a rare medical condition.

Doctors diagnosed them with Twin-to-Twin Transfusion Syndrome (TTTS) when their mother was 21 weeks pregnant.

The condition means one baby gets too much blood and the other too little. In almost all cases it leads to death of both twins, if it's not treated.

Consultant obstetrician, Professor Fergal Malone, decided the foetuses had to be operated on while they were still inside their mother's womb if they were to have any chance of surviving.

He performed the life-saving procedure in the hospital's new foetal operating theatre on January 10 this year. The operation involved the obstetrician and his team inserting a camera, less than an eighth of a inch thick, and other tiny surgical instruments, into the womb.

The camera helped the team identify abnormal blood vessels, which were then repaired using laser therapy.

The girls were born by caesarean section three months later on April 7.

Lauren and Sophie are among the first children in Ireland to survive the pioneering surgery. It also saved the lives of twin boys Ryan and Dylan Kershaw, who were born in March last year.

The radical surgery was previously available in only a handful of clinics in Europe and North America.

Mr and Mrs Green said their babies would not have survived without Professor Malone and his team and thanked them for their care. "Paul and I are absolutely delighted that this story has had such a happy ending," said Mrs Green (43).

"We would like to thank all the staff in The Rotunda for their excellent care and professionalism. Lauren was discharged home with me after five days and Sophie joined us at home nine days later. Now the girls are three months old and are thriving."

Professor Malone said almost a third of all twin pregnancies were identical, and up to a quarter of identical twins could develop Twin-to-Twin Transfusion Syndrome.

"When one considers that up until recently survival for these babies was so poor, it is gratifying to see the Irish health service investing in new technology that provides such an immediately apparent benefit to our patients."