Britain's Prince William visits his wife Kate at a London hospital where she's being treated for acute morning sickness.

News that the much-watched royal couple are expecting their first child travelled quickly around the world.

On the streets of Paris, the royal pregnancy was cause for congratulations.

(SOUNDBITE) (French) PASSERBY SAYING:

"Ah, well it's great for her! It's perfect! It's normal!"

(SOUNDBITE) (French) MALE PASSERBY SAYING:

"Well, I'm happy for them, because it's always good to have kids. I mean, that's it. My brother's also going to have a kid, so there you go."

No due date has been announced, but a royal spokesman said the Duchess is less than 12 weeks pregnant.