And when that momentous occasion does occur, what better way to celebrate than by raising a glass of a new specially brewed ale called Heir Raiser?
That's just what patrons will be treated to at a pub named after the Duchess of Cambridge in Windsor, Berkshire, the Evening Telegraph reports.
"The day after the baby is born, we are going to be throwing a party with tea and cakes," pub manager Daniell Park says. "We have got some banners ready to go up when we find out whether it's a boy of a girl. We have also got our special McMullen's beer, which is already proving to be very popular."
What's more, the pub will also be giving a bottle of champagne to the person who most accurately guesses the date and time of the little one's birth.
Not a drinker? No worries.
There's certainly other ways to commemorate the big event, including dressing your own bundle of joy in a special royal onesie created by Jammies Prêt-à-Porter and packaged in an adorable jam jar.
Not surprising, there's plenty more royal baby-inspired items currently available.