The couple's second child will be about 21 months younger than Prince George
Credit: Max Mumby/Indigo/Getty

It will be a very special wedding anniversary for Prince William and Kate next April.

“Their Royal Highnesses The Duke and Duchess of Cambridge are delighted to confirm they are expecting a baby in April 2015,” a simple statement from Kensington Palace announced Monday morning – one that dashed recent speculation that the royal couple, both 32, were expecting twins.

April 29 will mark the fourth anniversary of William and Kate, and their son, Prince George, born July 22, 2013, will be 21 months old by then. As it is, April is an especially auspicious month for royal births: Queen Elizabeth will turn 89 next April 21.

The palace statement also said, “The Duchess of Cambridge continues to be affected by Hyperemesis Gravidarum, but her condition is steadily improving.”

She is set to join William on her first official engagement back on royal duty Tuesday, when the couple welcomes President Tony Tan Keng Yam of Singapore to London.

If she is well enough, Kate will ride the short distance to Horse Guards Parade across London, where the ceremony is to take place.

Later, she is expected at the Natural History Museum for the Wildlife Photographer of the Year awards.

Tuesday’s events will mark the first time that Kate has been seen officially since her pregnancy was announced Sept. 8.

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