Britain's Duke and Duchess of Cambridge are "immensely thrilled' they're expecting another baby.
The couple, who got married in 2011, are overjoyed that their 14-month-old son Prince George will soon have a little sibling, even though Catherine has been struck down with severe morning sickness again.
Speaking after his visit to Oxford University yesterday (08.09.14), Prince William told the BBC: "She's feeling OK, it's been a tricky few days, a week or so, but obviously we're immensely thrilled, it's great news.
"It's early days but I'm hoping things settle down and she feels a bit better soon."
The happy news was announced yesterday by Kensington Palace after the Duchess - who was known as Kate Middleton before she married William - was forced to pull out of the visit, where they were expected to open a Chinese studies building.
A post on the British Monarchy Facebook page read: "Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting their second child.
"The Queen and members of both families are delighted with the news."
The statement added: "As with her first pregnancy, The Duchess is suffering from Hyperemesis Gravidarum."
The statement continued: "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."

Britain's Duchess of Cambridge knew there was a possibility she'd suffer with severe morning sickness.
The 32-year-old royal, who announced yesterday (08.09.14) she is pregnant with her second child, had prepared herself for the likelihood that she'd be struck down with Hyperemesis Gravidarum again after she battled with the same complications when she was expecting 14-month-old Prince George.
A source told E! News: "This bout of sickness has come on very fast and Kate's gone from feeling great to feeling terribly ill very quickly. They had thought that she might be lucky and not suffer it this time, but they knew before they decided to have another baby that it was a possibility. Kate's very practical and takes everything in her stride and decided that she'd manage to cope and just get on with it if it happened again."
Catherine and Prince William were forced to announce their baby news after the beauty pulled out of their visit to Oxford University yesterday due to the sickness.
The source added: "Whilst it's terrible luck that Kate's so unwell with Hyperemesis Gravidarum yet again, they're hoping she'll be on the mend in no time."
Meanwhile, the Duchess' mother Carole Middleton has reportedly been helping her daughter, who is being cared for by doctors at Kensington Palace in London, with little George while she's been ill.
The source explained: "She has been visiting them a lot, staying over for several days at a time, cooking Kate's favourite food and helping with George as Kate has very little energy to rush around after a toddler."

Britain's Duchess of Cambridge's attendance at royal engagements will be decided on "case-by-case".
The 32-year-old royal, who is pregnant with her second child, was forced to pull out of her visit to Oxford University with husband Prince William yesterday after being struck down with severe morning sickness, and Kensington Palace has announced any other changes to her schedule, including her trip to Malta later this month and attendance at the Invictus Games in London this week, will be decided on nearer the time.
A spokesperson told HELLO! magazine: "We will be planning this on a case-by-case basis - it's too early to talk about Malta and the Invictus Games."
Catherine - who was known as Kate Middleton before she married William in 2011 - is currently being looked after by medical staff at Kensington Palace in London.
Meanwhile, the Duchess suffered similar complications when she was in the early stages of her pregnancy with her son Prince George, 14 months, in 2012.
Despite feeling unwell Catherine is overjoyed she's pregnant again, and the prince's grandmother Queen Elizabeth is said to be "delighted."
A post on the British Monarchy Facebook page yesterday (08.09.14) reads: "Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting their second child.
"The Queen and members of both families are delighted with the news."

The Duchess of Cambridge should drink flat cola to ease her pregnancy sickness, a medical expert has said.
The 32-year-old royal - the wife of Prince William - announced yesterday (08.09.14) she is pregnant with her second child but she has been diagnosed with Hyperemesis Gravidarum, which is a severe form of morning sickness.
Catherine suffered from the same condition when she was pregnant with her 14-month-old son Prince George and Alison Edwards - Senior Lecturer in Midwifery at Birmingham City University - has recommended the sweet soft drink as a potential remedy.
Edwards said: "Though there is an increased chance due to having the excessive sickness before she may well have an entirely different experience this time with little or no sickness. Though there is no 'cure' for morning sickness - and certainly not hyperemesis - there are steps that can be taken to try to settle the unpleasant symptoms.
"Though there are few sources of scientific evidence to support any 'remedies', making sure fluid intake is maintained is a priority. Flat coke has been found to help here as can arrowroot or ginger."
Other potential remedies include changing to a low-fat diet and wearing travel bands.
Edwards added: "Some women swear by travel bands. Small low fat meals can help and avoiding anything spicy. If the symptoms become excessive then medical advice must be sought as there are medications that can reduce the sickness and nausea; these do need prescribing however.
"Excessive morning sickness can make women unwell and certainly miserable, so plenty of support and rest are vital, especially if admission to hospital is required as Kate was last year."
Catherine - formerly known as Kate Middleton - is currently being treated for her sickness at her Kensington Palace home in London, and her mother Carole Middleton has been caring for little George while she's been ill.

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