Duke and Duchess of Cambridge expecting a child

Good luck messages were flooding in this evening after St James's Palace announced that the Duke and Duchess of Cambridge are expecting a baby.

However the Duchess is currently spending a second night in hospital as a precaution after developing severe morning sickness and is expected to remain in hospital for a few days.

This afternoon the couple's own website crashed due the amount of traffic the announcement generated.

A statemnent posted earlier said: "Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting a baby.

"The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall and Prince Harry and members of both families are delighted with the news.

"The Duchess was admitted this afternoon to King Edward VII Hospital in Central London with Hyperemesis Gravidarum. As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter. Hyperemesis Gravidarum is very acute morning sickness, which requires supplementary hydration and nutrients."

In a statement, St James's Palace said: "Their Royal Highnesses the Duke and Duchess of Cambridge are very pleased to announce that the Duchess of Cambridge is expecting a baby.

"The Queen, the Duke of Edinburgh, the Prince of Wales, the Duchess of Cornwall and Prince Harry and members of both families are delighted with the news."

It said the duchess was being treated in hospital after suffering from hyperemesis gravidarum, which requires supplementary hydration and nutrients.

"As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter," it added.

In a Twitter message issued minutes after St James's Palace announced the news of the pregnancy, Prime Minister David Cameron said: "I'm delighted by the news that the Duke and Duchess of Cambridge are expecting a baby. They will make wonderful parents."

Labour leader Ed Miliband said: "This is wonderful news for the Duke and Duchess of Cambridge. The whole country will be thrilled. Justine and I offer Kate and William our warmest congratulations." 

Dr Rowan Williams, the Archbishop of Canterbury, who married the royal couple in Westminster Abbey in April 2011, said: "The whole nation will want to join in celebrating this wonderful news.

"We wish the Duchess the best of health and happiness in the months ahead."