Fifty years after being pregnant, women still have cells in their bodies from the child they carried. What's more, according to research published in The Lancet, these aren't just any old cells, but stem cells which can grow into whatever the body needs.
There's speculation that this extra boost of fresh cells when a woman is pregnant might even hold the secret of why women live longer than men.
Reporter Claudia Hammond meets the scientists who carried out the research at Imperial College London in a team led by Irene Roberts, Professor of Paediatric Haematology.
