Surgeons have performed heart surgery on a 25-week-old foetus after practising on a grape.
They used a hair-fine wire, a miniature needle, a tiny balloon and a catheter to carry out the life-saving operation on the unborn child's heart.
It was a medical first for the surgical team at CHA Hollywood Presbyterian Medical Center, in Los Angeles.
The LA Times reported that the foetal heart - which is about the size of a walnut - was developing with one valve too narrow, a condition known as severe aortic stenosis.
This meant the amount of blood coming into the heart was being severely restricted and it was backing up in the left ventricle.
Without the surgery, the child would have been born with a life-threatening condition known as hypoplastic left heart syndrome (HLHS).
To practice for the delicate procedure, the surgeons used a jelly mould to replicate the mother's body, and a single grape representing the foetal heart.
A team of specialists carried out the nerve-wracking operation on September 25.
The mother was given a local anaesthetic and the foetus was also given anaesthesia and a muscle relaxant so it would not move in the mother's womb during the operation.
Dr Ramen Chmait, assistant professor at Keck School of Medicine of USC and director of LA Fetal Therapy, said: "There is no question in my mind that without this procedure the baby would have had HLHS.
"Now the baby has a chance to have the left ventricle recover with some good function."