THE Duchess of Cambridge is improving in hospital as she continues to be treated for severe pregnancy sickness, St James's Palace has announced.
A short statement from a spokesman said the Duchess, the former Kate Middleton, was "continuing to feel better" and was "immensely grateful" for all the messages of support she has received.
The good news was reflected in the Duke's expression as he left the King Edward VII Hospital in London smiling broadly after spending more than six hours by his wife's bedside today.
However, the Duchess is not expected to leave hospital for a few more days. The Duchess is being treated for hyperemesis gravidarum, a severe form of morning sickness.
A St James's Palace spokesman said: "The Duchess of Cambridge is continuing to feel better.
"She and the Duke are immensely grateful for the good wishes they have received.
"She will remain in hospital at present and will continue to be treated for hyperemesis gravidarum
The Duke arrived at the hospital just before 11.30am, walking straight inside without glancing at the scores of reporters and TV crews standing behind barriers on the other side of the road.
Prince William arrives at the King Edward VII hospital as a man wearing a Prince William mask is escorted away by a police officer (Getty Images)
He looked far happier when he left the hospital just after 5.45, though he did not make any comment on the Duchess's condition. The Duchess has not, so far, had any other visitors.
The Duke had spent several hours with the Duchess on Monday, when she was admitted to the hospital, leaving at 8.20pm to spend the night at Kensington Palace.
Members of the media stand outside the King Edward VII hospital ( EPA)
The Duchess, 30, was staying with her parents over the weekend when she began to feel unwell. She had only found out last month that she was pregnant and the couple had been intending to wait until the Duchess had reached the 12-week stage before going public with the news.
They decided to announce the pregnancy early knowing the Duchess's hospitalisation would make it impossible to keep the news a secret in the age of Twitter.
Royal aides have not disclosed how many weeks pregnant the Duchess is, but have confirmed she is less than 12 weeks, and that the pregnancy is in the "very early stages".
The Duchess's condition is three times more common in women expecting twins than in women carrying one baby, and this morning the odds of the Duchess having twins were slashed from 50/1 to 8/1 by Paddy Power following a rush of bets.
The Duchess's immediate diary engagements have been cancelled because of her illness, and it now seems unlikely she will carry out any official duties before Christmas, with royal aides predicting she will be in hospital for several days and will then require a period of rest.