The Duchess of Cambridge's pregnancy sickness has forced her to cancel an appearance at Wednesday's UK premiere of The Hobbit.
Kate is suffering from the condition known as hyperemesis gravidarum which leaves expectant mothers with constant nausea and regular vomiting.
A St James's Palace spokesman said: "The Duchess of Cambridge will not attend The Hobbit premiere tomorrow evening and will continue to rest privately.
"The Duke of Cambridge will attend as planned."
At the Winter Whites Gala in aid of homeless charity Centrepoint on Friday, Prince William joked about Kate’s morning sickness should be re-named “day and all-night sickness”.
He told charity boss Michael O’Higgins: “It’s a long old process but she is getting there. She feels like it is going to go on for ever.”