The 33-year-old pop diva, who is currently a coach on the US version of The Voice, is notoriously secretive when it comes to her private life and has kept predictably schtum about the pregnancy claims so far. However, her future mother-in-law may have let the cat out of the bag.
Responding to rumours that the couple might be moving from Los Angeles to the East Coast, Matt's mum told In Touch: "When you have a baby, you're not planning on moving anywhere anytime soon!".
Showbiz reporters immediately seized upon the remark as confirmation of Christina's pregnancy.
The reveal comes just a week after Christina told her 11.6 million Twitter followers of her engagement to Matt. "He asked and I said..." she tweeted, followed by a picture of Matt and her holding hands, showing a whopping engagement ring.
He asked and I said...... pic.twitter.com/XWZVZOjDX1
- Christina Aguilera (@xtina) February 15, 2014
The pair met on the set of modern camp classic Burlesque, in which Christina co-starred with Cher, when Matt was working as a production assistant. They had been dating for three years before Matt popped the question on Valentine's Day with a ring that, according to a People magazine source, he had designed himself.
It will be Christina's second pregnancy, as the 'Candyman' singer already has a six-year-old son with her ex-husband, music executive Jordan Bratman.
She has previously spoken of her love for little Max, telling talk show host Ellen DeGeneres: "He's the love of my life, and I adore him. He's such a character, and he's so happy and at the end of the day, that's what's most important."