Doctors in Japan have successfully transplanted liver cells derived from embryonic stem cells into a newborn baby, in a world first that could provide new treatment options for infants.

The newborn was suffering from urea cycle disorder, where the liver is not capable of breaking down toxic ammonia.
But the six-day-old was too small to undergo a liver transplant, generally not considered safe until a child weighs around six kilogrammes (13 pounds) at around three to five months old.
Doctors at the National Center for Child Health and Development decided to try a "bridge treatment" until the baby was big enough, injecting 190 million liver cells derived from embryonic stem cells (ES cells) into the blood vessels of the baby's liver.