Women who want to have children should start trying for a baby before they turn 30, according to one of Britain's top fertility doctors.

In a letter to the Education Secretary, Professor Geeta Nargund has called for fertility lessons to be put on the school curriculum.

"I have witnessed all too often the shock and agony on the faces of women who realise they have left it too late to start a family," she wrote.

"For so many, this news comes as a genuine surprise and the sense of devastation and regret can be overwhelming."

She says it's about educating young women - not telling them when to have children.