Kate Middleton 'had to take a fertility test' before marrying Prince William, claims royal author

Prince William and Kate Middleton will be celebrating their 12th wedding anniversary next month. The Prince and Princess of Wales exchanged vows in 2011, and have since gone on to have three children, Prince George, Princess Charlotte and Prince Louis. 

However, one royal author has claimed that before the couple tied the knot, Kate 'had to take a fertility test' to ensure that she could have children. 

William and Kate met at university in 2001, and were close friends before embarking on a romantic relationship a couple of years later. They split briefly in 2007 but reconnected just a few months later, with the pair reportedly making a marriage pact during a make-or-break trip to the Seychelles. 

The late Queen Elizabeth II was said to be very impressed by Kate, and insiders praised her for her 'stoicism' during their short break-up - asserting that this cemented her future role as Queen Consort.

But according to Tom Quinn, when William decided he wanted to marry Kate, the Princess underwent a fertility test. 

In his book Gilded Youth: An Intimate History of Growing Up in the Royal Family, he writes: "These are always carried out to ensure a future Queen is able to have children. If Kate had not been fertile, there is little doubt the marriage would have been off."

He also goes on to allege that this is considered a common practice for women entering the royal fold, claiming that the late Princess Diana was subjected to similar treatment. 

Quinn claims: "Diana complained in a brief encounter with the present author that she had in all innocence thought her premarital check-ups had to do with general health, only realising later on that she had actually been tested for fertility. 

"'I was so innocent I just went along with everything at that stage,' she said."

Quinn's book, which was released last month, 'interweaves exclusive testimonies from palace staff with historical sources' to examine how various members of the royal family's childhoods have impacted their adult lives.