Zara’s former rugby player husband Mike Tindall confirmed the news on the latest episode of the podcast he co-hosts, the Good , The Bad & The Rugby.
"It's been a good week for me, had a little scan last week - third Tindall on its way,” Mike, 42, said enthusiastically to his co-hosts.
When Mike’s co-hosts asked how the Queen’s granddaughter was doing, the former rugby player explained that she was doing well but being “careful” given their previous miscarriages.
"Z is very good, always careful because of things that have happened in the past, and really looking forward to it," he said.
Zara, who is the daughter of Princess Anne, previously revealed that she had suffered two painful miscarriages before becoming pregnant with Lena, 2, the couple’s youngest daughter.
Mike, who shares two daughters with Zara, went on to say that the couple hadn’t told the news to their eldest daughter, Mia, 6, out of fear of her telling her school friends.
"We haven't told Mia yet because we knew she would tell everyone at school,” he quipped. "Now that we've gone through the scan, yes of course we'll tell her.
"She'll be happy about it, she's been requesting another sister or brother, so we've hopefully fulfilled that role for her.
"She just wants something different now. Lena's growing up - she's two-and-a-half now - she wants something younger to play with and dress up!" he added, referring to his youngest child.