Kate and William expecting first baby
The Duchess of Cambridge has been admitted to hospital with an acute form of morning sickness as officials announce the royal pregnancy
3rd December 2012 - The Duke and Duchess of Cambridge are expecting their first baby.
The announcement from St James' Palace has been made earlier than normal because Kate is in hospital suffering from an acute form of morning sickness called hyperemesis gravidarum.
The Duchess of Cambridge is not believed to be past the first 12 weeks of pregnancy yet.
St James' Palace says the couple found out about the pregnancy "recently" and 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".
Prime minister David Cameron tweeted: "I'm delighted by the news that the Duke & Duchess of Cambridge are expecting a baby. They will make wonderful parents."
The couple's first child would be third in line to the throne, after Prince Charles and William.
Recent Royal engagements
Last week, as William and Kate toured Cambridge, a well wisher presented William with a baby romper suit with the slogan "Daddy's Little Co-Pilot". The Prince, who is an RAF helicopter rescue pilot said he'd keep it, but gave nothing else away.
On Friday, Kate visited her old school at St Andrew's School in Pangbourne, Berkshire, and was seen having fun playing hockey despite wearing high heels.
Acute morning sickness
The Duchess of Cambridge is being treated for severe morning sickness at the King Edward VII Hospital in London. The condition is hyperemesis gravidarum, also known as HG. It causes constant nausea and vomiting, often needing admission to hospital.
St James's Palace said in a statement: "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."
Not being able to keep food and fluids down increases the risk of dehydration and kidney problems, which is why urgent medical treatment is needed.
HG needs specialist medical care. Fluid levels and nutrients need to be maintained and ketosis caused by raised levels of poisonous ketones may need to be treated.
"It can be really horrible," says Professor Tim Draycott from the University of Bristol, a consultant obstetrician and spokesperson for the Royal College of Obstetricians and Gynaecologists. "About 30% of women get some sort of sickness in pregnancy. About one in 200 to one in 100 women get the very severe version, the hyperemesis that Kate has at the moment.
"It's a very uncomfortable condition, you feel very unwell."
How will the condition affect Kate's routine during the rest of her pregnancy? "It usually settles after about 12-13 weeks," Professor Draycott tells us. The hormone hCG - human chorionic gonadotropin - starts to reduce after that time. "The sickness resolves. If you ask most women it's the first third of pregnancy where sickness complicates pregnancy."
After being admitted to hospital for a few days, Professor Draycott says: "You get rehydrated intravenously then you'll be allowed to go again."
However, if the extreme sickness returns, more hospital visits would be needed and further rehydration. "It's very uncommon, but it can last past 20 weeks."
HG can leads to weight loss in pregnancy, which could result in a baby having a low birth weight.
Hyperemesis gravidarum is unlikely to cause harm to the growing baby, he says: "There's a very tiny chance of it affecting the baby's growth."
The main complications are from having inadequate treatment, which should not be a concern for Kate he says: "Clearly she'll be being treated adequately."