Will it be a Prince or Princess?
Duchess of Cambridge, Kate Middleton announces her pregnancy after being hospitalised with acute morning sickness.PT0M0S 620 349
When Prince Charles and Princess Diana announced they were expecting their first child it was a very royal occasion.
The couple attended a formal luncheon, complete with ornate bouquets and silverware, on the morning of November 5, 1981.
London's lord mayor, Sir Christopher Leaver, made a sentimental speech, saying the memory of their wedding "glows with the everlasting lustre of a gold ingot".
He went on: "A gold ingot that has now been supremely hallmarked by this morning's announcement that your royal highnesses are to be blessed with a child."
In a news report of the announcement, a journalist said Princess Diana would take on lighter duties and, over file footage of her greeting crowds in the rain, he editorialised: "You can't go on getting soaked like this, not now you can't!"
Now, 31 years on, things have changed. There is no formal function, no silver spoons and certainly no gold ingots.
Instead Clarence House simply tweeted the news announcing the Duke and Duchess of Cambridge were expecting their first child.
The tweet linked to a four-paragraph, sparsely written media release, much of which detailed the severe nausea that had put the Duchess in hospital.
The lack of royal ceremony is not the only difference between the two announcements of impending heirs to the throne.
It has been 585 days since Prince William and Catherine were married at Westminster Abbey on April 29, 2011.
During an interview after the couple announced their engagement, Prince William said they would wait to have children and take their marriage one step at a time.
Prince Charles and Princess Diana announced the news they were expecting their first child just 100 days after their wedding on July 29, 1981.
The Duke and the Duchess are both 30, while Prince Charles was 32 and Princess Diana was 20.
The difference in maternal ages is very much in line with Australian averages.
In 1980 40 per cent of new Australian mothers were aged between 20 and 24, while just over 10 per cent were aged between 30 and 34, according to the Australian Institute of Family Studies.
In 2008 most women - or 30 per cent - became mothers between the ages of 25 and 29, closely followed by women aged between 30 and 34.
The Duchess and Princess Diana both had difficult early pregnancies.
While Catherine has been hospitalised with hyperemesis gravidarum, Diana had a scare at 12 weeks when she fell down a staircase at Sandringham, British broadcaster ITV reported.
Princess Diana was said to have complained during her pregnancy: "The whole world is watching my stomach."
It's a sentiment Catherine can probably relate to in the age of the internet, with more than 2000 news articles published online within seven hours of the announcement.