David Tennant and his wife Georgia Moffett now have four children after she gave birth to a baby girl. The Broadchurch star was congratulated about his happy news when he went on air on Absolute Radio.
The couple now have "two of each" the actor quipped, although he didn't say when their daughter was born or what they've decided to call her.
Her siblings are Olive, four, Wilfred, two, and 13-year-old Ty, Georgia's son from a previous relationship. David adopted Ty on their marriage four years ago.
David Tennant and Georgia Moffett have been married for nearly four years
The 44-year-old actor confirmed the new arrival when he joined presenter Christian O'Connell in hosting his breakfast show.
Asked about his growing family, the former Doctor Who star said: "I know, number four has arrived, yeah." Christian continued: "Wow, what is it, like The Waltons round there at The Tennant household?"
David laughingly added: "I know, it's getting a bit ... it's a bit of a brood!" He also predicted that they would be having "a sleepless Christmas".
Georgia, now 30, met her husband when she starred as his daughter in an episode of the fantasy show. She is also the real life daughter of Peter Davison, the fifth actor to take on the role of the famous Timelord.
The Scotsman tends to bat away questions about the curious coincidence in interviews.
When a Guardian journalist joked that it was as if he'd deliberately picked a partner who was the daughter of a Doctor, he responded: "That's exactly what I did, yes, and there were very few candidates available. It was a limited field."
The couple met on the set of Doctor Who
On a more serious note, he said he felt "blessed" to have such a happy home life. The couple married on 30 December, 2011 celebrating the following day with a New Year's Eve party at London's Globe Theatre.
The festivities included fireworks and a serenade by a piper. Guests including Stephen Fry and Two Pints of Lager and a Packet of Crisps actor Will Mellor.
Her father Peter was particularly thrilled about the marriage, saying: "It's great because David is a genuinely nice guy.
"I'm delighted Georgia has found happiness because she hasn't always had an easy life."