Women who want to get pregnant should start trying before they hit 30 or risk never having children, warns one top British fertility specialist.

One of Britain’s top fertility specialists, Professor Geeta Nargund is warning women not to wait until they’re 30 to have a baby to avoid a ‘fertility time bomb’.

The top gynaecologist, who wrote her concerns in a letter to British Education Secretary Nicky Morgan, said there is a desperate need for fertility education and urged the government to consider including the subject in the national curriculum.

Prof Nargund, who is lead consultant for reproductive medicine at St George’s Hospital in London, believes that teenagers need to know about the dangers of delaying parenthood, because of the increasingly large burden IVF for women in their late 30s and 40s is causing the British taxpayer.

According to the Daily Mail, Nargund wrote in the letter that a growing number of women were being left childless as a key reason of waiting too long.

“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.

“And so often the cry will be “Why did no one warn me about this?”

Through education she hopes young people will be able to be able to make the best decisions for themselves.

“Information is power and the best way to empower people to take control of their fertility is through education,” she said.

Last year, Australia’s birth rate fell to its lowest point since 2006; however, the fertility rate among older mothers between the ages of 40 and 44 years increased, according to the Australian Bureau of Statistics (ABS).

“Over the past 30 years, fertility rates for these older mums have nearly tripled, and today’s results see the trend continuing,” Denise Carlton from the ABS said.