It's the big moment when the expecting couple reveals the big news to family and friends.
Is it a boy? Or is it a girl?
And in the case of the royal baby, the world holds its collective breath as it waits to find out: boy or girl, prince or princess? Kate Middleton is approaching the midway point in her pregnancy, meaning she could find out the sex of her baby if she chose.
Gender-reveal parties have become big business in the United States, with conversations related to the topic up 140 percent in one year, according to BabyCenter.com.
But they haven't quite caught on in the United Kingdom in the same way, ABC News' royal contributor Victoria Arbiter said. "It's not like the U.S., where there's a party for everything," she said. "British people don't like to make a fuss or draw too much attention to themselves." And despite already having more attention paid to them than anyone else in the world, this includes the royal couple.
Which is too bad, given the near-countless creative ways Kate Middleton could tell the queen if she's expecting a boy or a girl.
The most popular way to reveal is with a cake. The expectant parents will slice a white or other gender-neutral- colored cake in front of family and friends and reveal a pink or blue inside. Sara Gramling, vice president of public relations for Magnolia Bakery, said cupcakes are also gaining popularity. "When the guests and parents take a bite into the cupcake, it's revealed if they're having a boy or girl with the different color butter creams -- pink or blue. It's a nice way for everyone to find out together."
Scratch-off tickets are also a popular way to reveal a baby's sex, especially for expectant parents whose family and friends may be spread out around the country. The parents find out the baby's gender, order the appropriate scratch-off tickets and drop them in the mail. Some may elect to scratch the tickets together over Skype to share the excitement. Scratcher maker Inklings Paperie has just created a line of prince and princess tickets, complete with subtle details from the royal wedding, including the silhouette from Kate's vintage Cartier crown and chevrons from the Middleton family crest on the reverse side. It reads "Prince or Princess ... What Will It be? Scratch the Carriage, and You Will See!"
Though handing the queen a scratch-off ticket probably won't happen, it's a far more likely scenario than the latest gender-reveal trend, according to BabyCenter. That would be paintball fights, with, you guessed it, a pair of blindfolded expectant parents shooting one another with pink or blue paint before taking off their blindfolds to learn the sex of their unborn child.
There's also balloon releases, or simply unwrapping a box with a blue or pink baby onesie inside. But the royal baby gender reveal will likely be as understated as it gets. And what's more, it won't likely happen until after the birth.
"A note is put on the gates of Buckingham Palace that will announce the happy arrival of a new baby to the public," said Arbiter. "And it's a lovely old tradition."
It is, in fact, the way the world learned the details of William's arrival, including the time of his birth.
But if Kate and Will did decide to break with tradition and told the world if they were having a boy or a girl before the baby's arrival, it would, of course, be done on the grandest of scales.
"If they were to reveal the gender of their baby to the world, and if the British public were into a big fuss," said Arbiter," I think the best way to really reveal the birth of the baby would be pink or blue fireworks off the roof of Buckingham Palace."