Doctors have treated a baby with brittle bone disease while still in the womb, using stem cell technology.
The baby was treated while still in the womb
The Swedish team took genetically unmatched cells from another foetus to treat the unborn girl, who had been diagnosed with Osteogenesis Imperfecta.
The condition means she is especially prone to fractures but she is now two- and-a-half and has only suffered three - fewer than might have been expected.
But Karolinska Institute researchers said stem cell therapy was not a cure.
Osteogenesis Imperfecta (OI), or brittle bone disease, is caused by a genetic defect that impairs the body's production of one of its 'building blocks' - a protein called collagen.
Having either less or a poorer quality of collagen than normal means the bones are weak and can fracture easily, by merely coughing or turning over in bed, for example.
To date, there is now way to cure the genetic defect, but researchers have giving children with severe OI a transplant of genetically matched bone marrow stem cells to produce new collagen can help.
Stem cells are very primitive cells that have the capability to become any cell in the body.
However, it can be hard to find a suitable stem cell donor who is a good genetic match.
The Swedish team set out to investigate whether using mismatched stem cells from the livers of aborted foetuses would be a suitable alternative.
They treated a baby girl, yet to be born, who had been diagnosed with severe OI and already had multiple fractures.
At the 32nd week of the pregnancy, the researchers transplanted the stem cells into the baby girl.
She was born three weeks later by Caesarean section.
When she reached nine months of age, the researchers checked how well the donated stem cells had taken.
There were no signs that the baby girl had rejected the stem cells, even though they were foreign.
Now aged two and a half, the girl has so far had only three fractures since birth.
People with the most severe form of OI can have several hundred fractures in a lifetime.
Lead investigator Celia Götherström said: "The big advance is that we have given stem cells that are completely unmatched and they have not been rejected.
"It means we could give stem cells from any person to another person."
The researchers will follow the child as she grows to check how the transplant is progressing. They also hope to treat other babies with OI in the same way.