The BBC's Fergus Walsh: "Incredibly, the embryo implanted outside the womb"

King's College Hospital in London said a team of 26 medical staff had delivered a baby boy, who had grown inside his mother's fallopian tube, together with two sisters who developed normally in the womb.

The hospital said it was the first reported case of the multiple birth of babies that had developed both inside and outside the womb.

Ronan, Olivia, Mary and their mother are doing well, a hospital spokesman said.

Life-threatening

Jane Ingram, 32, had not been taking fertility drugs but discovered she was carrying triplets 18 weeks into the pregnancy.

Ronan developed outside the womb

Ten weeks later, a routine scan revealed that one of the embryos had developed outside the womb in the fallopian tubes - a situation known as an ectopic pregnancy, which is potentially life-threatening.

In an ectopic pregnancy the woman's fallopian tube ruptures, usually leading to loss of the pregnancy and massive internal bleeding which can prove fatal for the mother.

But in Ronan's case, when the tube ruptured the embryo attached itself to the mother's uterus and created its own "womb", with its own blood supply, in the mother's abdominal cavity.

Scans at the time showed only a normal twin pregnancy and it was not until much later doctors discovered the truth.

Astounding odds

Consultant obstetrician Dr Davor Jurkovic, who delivered Ronan, along with his two sisters, said it was a "miracle" that the triplets and the mother had survived.

Davor Jurkovic said the babies and mother were doing well

He said the chances of such an embryo surviving is one in 60 million.

And Mrs Ingram's bravery had been central to the success of the birth.

"Jane was absolutely incredible. The attitude of the patient in situations like this is crucial and her attitude was always positive," he said.

The BBC's Linda Duffin talking to Consultant obstetrician Davor Jurkovic

"She was fully aware of the risks but she was smiling all the way through, even in the last minutes before she was given an anaesthetic.

"She was very, very positive in everything we did and that was crucial. Just before the babies were delivered she turned to me and said 'I have faith in you'."

The triplets' father, a factory hand, told the Sun newspaper: "I'm the luckiest man alive, I can't wait for my family to come home."

Babies' progress

Following the birth, the babies were taken to the hospital's intensive care unit.

Dr Janet Rennie: Feared for Ronan's health

Dr Janet Rennie, a consultant paediatrician, said: "I was concerned that Ronan would have suffered stress from the position he was in and that he may have had problems breathing and with his limbs because he did not have the space and the nourishing atmosphere of the womb.

"But happily those concerns have not materialised. If anything he has been more robust than his sisters.

"He achieved natural respiration and came off the ventilator before the other two - perhaps because his lungs had to develop and were given the exercise they needed."

Mrs Ingram is expected to leave hospital soon, although doctor will have to monitor her progress as they were unable to remove the placenta Ronan developed from her stomach.