A dearth of marriagable men has left an “oversupply” of educated women taking desperate steps to preserve their fertility, experts say.

The first global study into egg freezing found that shortages of eligible men were the prime reason why women had attempted to take matters into their own hands.

Experts said “terrifying” demographic shifts had created a “deficit” of educated men and a growing problem of “leftover” professional women, with female graduates vastly outnumbering males in in many countries.

The study led by Yale University, involved interviews with 150 women undergoing egg freezing at eight clinics.

Researchers found that in more than 90 per cent of cases, the women were attempting to buy extra time because they could not find a partner to settle down with, amid a “dearth of educated men”.

Experts said the research bust the myth that “selfish career women” were choosing to out their fertility on ice in a bid to put their careers first.

They said sweeping social changes meant that many professional women now struggled to find a partner that felt like an equal match.

In recent decades, the gender balance at British universities has tipped dramatically.

In 1985, 45 per cent of UK students were female, but by 2000, 54 per cent were women.