One of the Britain's top National Health Service experts has issued advice for women who plan to have kids: Do it before age 30, or else don't even make the attempt.

Geeta Nargund, a consultant gynecologist and professor, issued the warning in a letter to Education Secretary Nicky Morgan. Calling for a change in the national curriculum, Nargund asked Morgan to let teenagers be taught about the potential health dangers of delaying parenthood as well as the costs of IVF treatment for women over 30.

In her letter, Nargund claimed Britain is facing a “fertility timebomb.” "I have witnessed all too often the shock and agony on the faces of women who realize 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. And so often the cry will be 'Why did no one warn me about this?' ” wrote Nargund in her letter.

Nargund's letter and warning have attracted mixed reviews from fertility experts and women across the world. Allan Pacey, chairman of the British Fertility Society, seems to stand firmly with her idea.

"You need to be trying by 30 because if there is a problem and you need surgery, hormones or IVF, then you've got five years to sort it out. If a woman starts trying at 35, doctors have got to sort it out when she is already on a slippery fertility slope," said Pacey in a statement.

However, a representative from the British Pregnancy Advisory Service said a majority of women will face absolutely no problem conceiving in their 30s.