While it might sound like unsupported gossip (Kate was apparently expecting twins last time around, remember?), betting has now been suspended on Kate and Wills having twins next year, prompting speculation that the rumours are true.
Last night (Monday, September 29), betting giant William Hill suspended betting on the couple expecting twins, following a 'rush' of first time punters putting money on it.
William Hill spokesman Rupert Adams said the flood of bets would normally mean there was truth in the rumours.
He told the Express: "We have had a load of unexpected bets including a large number of new accounts - with any other market I would say that people know."
Betting firm Coral followed William Hill's lead, suspending betting on all Royal baby themes.
So, rumours aside, what do we actually know?
Clarence House announced Kate's second pregnancy on September 8, saying both the Duke and Duchess, and their families, were 'delighted' with the news.
It was also confirmed Kate is suffering with hyperemesis gravidarum – extreme morning sickness.
The internet quickly went into meltdown with this news, with headlines screaming Kate MUST BE PREGNANT WITH TWINS because the condition is more common with multiple pregnancies.
Now, not to burst the twin bubble, but Kate did suffer with hyperemesis gravidarum when she was pregnant with Prince George. And a twin he ain't.
It's unlikely the Palace will announce anything more about Kate's pregnancy – other than to confirm the month she is due, much like they did with Prince George.
If Kate is expecting twins, the news might not be announced at all – until the family make their first appearance post-birth on the steps of the Lindo Wing, that is.
But that doesn't stop the tabloids claiming there will ONE HUNDRED PER CENT be twin girls for Kate and Wills next year.
Called Elizabeth and Margaret apparently.
They tried hard with that one.
More on Parentdish: