The former Kate Middleton has cancelled a planned appearance at the U.K. premiere of "The Hobbit" due to acute morning sickness.

Palace officials said Tuesday Prince William's wife, now known as the Duchess of Cambridge, will continue to rest rather than go to the show.

William still plans to go to the premiere.

Middleton has cancelled all public engagements since her brief hospitalization last week for severe nausea and dehydration. She is suffering from a condition known as hyperemesis gravidarum that causes sustained nausea and discomfort.

Her pregnancy is still in early stages.