Doctors plead for ‘saviour siblings’

Changes to rules that control the creation of 'saviour siblings' could benefit hundreds of couples and save the health services hundreds of millions of pounds a year, a leading IVF expert told The Observer yesterday.

A victim of its own success

Aspirin's ability not just to kill pain, but to prevent heart attacks and cancer too, is putting new research on its potential uses in danger, writes Diarmuid Jeffreys.

A matter of life and death

Scientists hope that by injecting human embryo stem cells into the brain, they will be able to cure Parkinson's disease. But is such radical treatment worth the risk? Vivienne Parry reports on the extreme side of medicine.

The time of your life

Your body clock is ticking, and scientists now understand its workings better. Ian Sample finds out how this knowledge could usher in a medical revolution.