Kate is suffering from a severe form of morning sickness.

Prince William and his wife Kate Middleton are expecting their third child, Kensington Palace announced on Monday, adding that Queen Elizabeth II was "delighted".

In a statement, the palace said that 35-year-old Kate was suffering from hyperemesis gravidarum, a severe form of morning sickness which also marked her previous pregnancies, and would not attend a planned event later Monday.

Source: Khaleej Times