Duchess of Cambridge is pregnant with third child

The Duchess of Cambridge with the Duchess of Cornwall (on her left) and Prince Harry (seated facing her). Image: Wikimedia

The Duke and Duchess of Cambridge are expecting their third child, Kensington Palace has announced.

The news of the duchess’ third pregnancy  delighted the Queen and both families.

The announcement also mentioned that, just like her two pregnancies, the duchess, who is now 35, is suffering from hyperemesis gravidarum, or severe morning sickness.

She had to beg off from her scheduled engagement at the Hornsey Road Children's Centre in London, which she was supposed to attend Monday afternoon.

The duchess is now being cared for, according to Kensington Palace statement.

According to BBC's royal correspondent Nicholas Witchell, the announcement came just in time for a "significant week" for the family "because Prince George is due to start at big school."

"Presumably his mother would be keen to take him to that, [but] whether she is going to be well enough to do that remains to be seen," he told BBC News.

"It had also been expected that the Duke and Duchess of Cambridge would be taking a foreign trip this autumn," he added.

"Whether they will be able to do that or whether the duchess will be well enough to do that also remains to be seen."

The expected child is set to become fifth in line to the throne after Prince Charles, Prince William, Prince George and Princess Charlotte. In March 2015, the revision of succession law allowed equal primogeniture, thus, royal sons could no longer precedence over their older female siblings in the line of succession.