Human kidneys grown inside pig embryos implanted in surrogate sows

Researchers grew human kidneys inside pig embryos for 28 days (Gareth Fuller/PA)

Scientists have, for the first time, grown human kidneys inside pig embryos that were implanted in surrogate sows.

The kidneys in the part-human, part-pig embryos were allowed to develop for 28 days – spanning the first trimester of a pig pregnancy.