Teenagers should be taught parenting and relationship skills to prepare them to be "child-ready" in good time, the Duchess of Cambridge has said.

The Duchess, who is expecting her third child next month, said it was important to prepare future mothers and fathers for parenthood, to enable them to cope with the "mental and emotional needs" of their children.

In a speech on the benefits of early intervention in supporting children’s mental health, she said early intervention would help to break “the inter-generational cycle of disadvantage”.

Speaking at a symposium of academics, professionals and charities organised by the Royal Foundation, the Duchess said: "I really do feel so passionately about the importance of early intervention, and that by working on new approaches together, we can make a real difference for generations to come."

In one of her last engagements before beginning her maternity leave, the Duchess announced she was setting up a steering group to explore how best to provide children with the best start in life.