LONDON, Oct. 20 (Xinhua) -- Britain's Prince William and his wife Kate are expecting their second child in April next year, an official statement said Monday.

"Their Royal Highnesses The Duke and Duchess of Cambridge are delighted to confirm they are expecting a baby in April 2015," a spokesman for Kensington Palace said in the statement.

"The Duchess of Cambridge continues to be affected by Hyperemesis Gravidarum, but her condition is steadily improving," the spokesman added.

The news about Kate's second pregnancy was announced in early September, and a string of public events have been canceled since then.

But on Tuesday, the 32-year-old duchess will join Prince William in an official event to welcome Singaporean President Tony Tan and his wife for a state visit, according to local media.

Also on the same day, she is expected to attend a ceremony of the Wildlife Photographer of The Year 2014 Awards at the Natural History Museum.

The second royal baby will be the fourth in line to the British throne right behind Prince George, the older brother who was born in July 2013.