It has become popular amongst politicians, entertainers and the British royal family.
The sex of the new royal baby will be a surprise to everyone, including the Duke and Duchess.
He acceded to the throne when he outlived his older brothers, George IV, who died without an heir, and Frederick, Duke of York.
The little prince or princess will either be an Aries or a Taurus.
Kate and William with the Princess of Cambridge in May 2015.
Will they hire a second nanny?
Kate and William with their children Charlotte and George.
But Maria could be given a helper - perhaps a fellow Norland nanny - as she cares for the three youngsters.
Kate is likely to take an extended period off to recover and nurse the latest addition to her family but is expected to attend Prince Harry and Meghan Markle's wedding on May 19.
Middleton is now pregnant with her third child, as she and husband Prince William are already parents to son Prince George and daughter Princess Charlotte. For those interested in being in the loop, the pattern of Kate's third birth will match the organization around Charlotte's arrival, rather than George's.
It is expected Kate will give birth around April 23 - as the hospital prepares for the hysteria from royal fans who are predicted to gather in vast crowds outside the famous wing.
Kate Middleton is due to give birth to her third royal baby this month in the private Lindo Wing at St Mary's Hospital Paddington. However, it's unknown at this point if George and Charlotte will join their new sibling for the pics.
However, that's not to say that Charlotte doesn't have quite a few years-possibly a lifetime-to wait until she will see her day as queen.
Kate is only 36 so has time to even out the numbers.
Apple powered by 100% renewable energy worldwide
The company says it has also made headway with its manufacturing partners and suppliers, though there's still some way to go. Japan has set a 22-24 per cent renewable energy target, and the European Union 27 per cent, for 2030.
Man struck by 'thunderclap' headaches after eating world's hottest chilli
He achieved this accomplishment by consuming 120 grams of the pepper in 60 seconds at the Arizona Hot Sauce Expo in November 2016. It's a no-brainer that eating a Carolina Reaper, a chili pepper bred to be the hottest on earth, will come with consequences.
Canadian junior hockey team bus crash kills 14
Steven Wilson, a co-worker in Weyburn, Sask., said it was Bieber's first season announcing for the team. Billeting families are a large part of junior hockey, with players spending years with host families.