Mothers are often warned that delaying pregnancy until they are older means their children face increased health risks.

Now a study suggests these may be outweighed by advantages, with older women likely to have healthier, taller, better-educated children.

This is because in industrialised countries they are generally brought into a world where improving social conditions as time passes lead to better general health and education.

Children born to older mothers have a higher chance of Down’s syndrome, Alzheimer’s disease, high blood pressure and diabetes in later life, and are also more likely to experience childhood cancer and autism.