The Palace has described the Duchess of Cambridge's morning sickness as "acute" and she is at King Edward VII Hospital in Central London, joined by her husband, Prince William. According to a source at St James's Palace, Kate arrived at the hospital from her parents' new home in Bucklebury.
The source adds that the couple decided to "be open" about Kate's pregnancy because she was admitted to the hospital. But, since it's so early, "we aren't going into detail about the pregnancy itself," the source says.
Kate, 30, also has canceled her next three official engagements.
According to the Palace, Kate is suffering from hyperemesis gravidarum, characterized by severe and persistent nausea and vomiting during pregnancy. If untreated, the patient can suffer dehydration and dangerous weight loss.
This is the first child for the royal couple, who wed in April 2011.