AceShowbiz -

Following the happy news that Kate Middleton is expecting her second child with Prince William, the palace reveals the Duchess of Cambridge is suffering the same morning sickness she previously battled during her first pregnancy. Kate is currently being treated at home in Kensington Palace.

The palace said in a press release posted on Monday, September 8, "As with her first pregnancy, The Duchess is suffering from Hyperemesis Gravidarum. Her Royal Highness will no longer accompany The Duke of Cambridge on their planned engagement in Oxford today. The Duchess of Cambridge is being treated by doctors at Kensington Palace."

William, who attended the Oxford engagement solo, said of his wife, "She's feeling OK thanks. It's been a tricky few days, a week or so. We're just basically thrilled, it's great news. Early days, we're hoping things just settle down and she feels a bit better. But it's important that we all focus on the big news, the big international and domestic things going on at the moment. I'm going to go and look after her now."

Hyperemesis gravidarum is a severe form of morning sickness which is characterized by weight loss and dehydration. Dr. Shilpi Mehta-Lee told New York Daily News, "Nausea and vomiting in pregnancy is really common, but hyperemenis gravidarum is a more specific disease characterized by prolonged nausea and vomiting, dehydration and at least a 5% body weight loss."

Shilpi added, "Every pregnancy is different, and it's not 100% clear if a patient has it in her first she will definitely have it in her second, but it's certainly more likely. About 15 percent who had it in the past will go on to have it again."