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Consultant gynaecologist Professor Geeta Nargund called for fertility lessons to be included in the national curriculum.
She said teaching young women about the dangers of delaying parenthood would ''empower people to take control of their fertility''.
According to the Mail on Sunday, which has seen the letter, Prof Nargund warned that fertility issues were placing a ''costly and largely unnecessary burden on the NHS'' as increasing numbers of women in their 30s and 40s sought IVF treatment.
She wrote: ''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.
''For so many, this news comes as a genuine surprise and the sense of devastation and regret can be overwhelming.''
She added: ''Information is power and the best way to empower people to take control of their fertility is through education.
''Ideally, if a woman is ready for a child, she should start trying by the time she is 30. She should consider having a child early because as a woman gets older, her fertility declines sharply.''
Prof Nargund, who is lead consultant for reproductive medicine at St George's Hospital in London, said educating people about fertility was ''very important for the public purse because it will help us to get more babies within the same NHS budget''.
Many young people were poorly informed about the impact of age on fertility and were unaware about the impact of smoking, too much alcohol or taking drugs, Prof Nargund said.
''Educated women are not necessarily educated about their fertility,'' she added.
Prof Nargund, 55, started a family with her husband at the age of 29, while working as a junior doctor, the Mail on Sunday reported.