India, March 16 -- In a surprising revelation, Kate Middleton had to undergo a fertility test to marry Prince William in 2011, media reports said.

This was a part of the protocol followed since the prince had chosen a bride outside royalty.

The test was conducted to ensure whether the future queen could bear children was apparently among them.

Talking about the odd practice, the author reportedly stated: "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."

The book claims Princess Diana had to go through the same medical tests before her wedding to Charles in 1981, as per the Hello Magazine report.

Prince William married Kate Middleton on April 29, 2011, in a grand ceremony at Westminster Abbey in London. Around 1,900 guests attended the wedding, for which a special eight-tier cake was commissioned and a public holiday declared in the country.

The royal couple is parents to three young children - Prince George, Princess Charlotte, and Prince Louis.

Published by HT Digital Content Services with permission from India Blooms.