A SET of new-born quadruplets made up of two pairs of identical twins were today "doing well" in hospital nearly a week after their birth.

The 10-million-to-one babies were born at the Victoria Royal Infirmary, in Newcastle, on December 27.

Their parents, Lisa and Sean Kelly, of Billingham, near Middlesbrough, were reported to be besotted with their new daughters.

The four girls are believed to be the first quads made up of two sets of identical twins to be born in the UK.

They were conceived through IVF treatment after Mrs Kelly, 35, struggled to fall pregnant naturally following the birth of her eight-year-old son, Cameron.

The babies, Heidi, Annabelle, Hannah and Jessica, were born by Caesarean section when Mrs Kelly was 31-and-a-half-weeks pregnant.

Heidi and Annabelle each weighed 3lb 3oz, Hannah was born weighing 2lb 11oz and Jessica was one ounce lighter at 2lb 10oz.

The quadruplets, who are all said to be able to breathe unaided, have since been transferred to University Hospital of North Tees, in Stockton, where they are expected to remain for several weeks.

A spokeswoman for the hospital said today: "They are all stable and doing well."

Mrs Kelly, a nurse, said she tried a number of fertility treatments before undergoing IVF privately at The London Women's Clinic, in Darlington.

After two unsuccessful attempts, two embryos were implanted and Mrs Kelly became pregnant.

A scan at eight weeks showed that each of the embryos had split into two, creating two sets of identical twins.

Mrs Kelly said: "When we heard we were expecting four ... we didn't dare to imagine the day we'd see them all. But looking at them now, it seems real and totally fantastic."

Mr Kelly, 34, an electrical engineer, described the birth of his daughters as amazing and added: "Last week I was a father-of-one and this week Im a dad-of-five."