Laura Wright is expecting her first child with husband Harry Rowland.
The mezzo-soprano and the former rugby star got married in December 2018 and their baby is due the day after their first anniversary.
Wright, who is 20 weeks pregnant, told Hello magazine: “It’s such a special time of year and the whole reason we wanted a winter wedding in the first place was because we love Christmas so much.
“This year will be even more amazing.”
Wright, 29, added she has been keen to keep the news a secret so has been hiding her growing bump under loose gowns for her performances, including one in Yorkshire last month for the qualifying rounds of the Invictus Games.
She said: “It’s only in the last two or three weeks that I’ve begun to show.”
The singer learned she was pregnant just 10 days before she ran the London Marathon and said she was not entirely focused on the task at hand when she took on the challenge.
She said: “There’s a lot of time to think when you’re running a marathon.
“Emotionally, I found the experience quite difficult. I’m very competitive so I wanted to do well, and give it my best shot, but I felt like I couldn’t do that.
“This was my fourth marathon and I know how they can be quite overwhelming – your energy stores get so depleted and you’re so exhausted.
“I was feeling quite tired anyway, and I felt a bit low. I didn’t know what to expect.
“At one point I was overtaken by a man in a rhino costume and I thought, ‘Wow, this is going really badly…’. I was really relieved when it was done!”
The full interview is in Hello magazine, out now.