The baby will be the pop icon’s third child and the pregnancy news comes after she spoke candidly about her hopes of starting a family with the personal trainer.
But what is known about the pair’s relationship and how did they meet?
The loved-up pair have been together since 2016, and met on the set of Britney’s music video for her song, Slumber Party.
The fitness fanatic told Men’s Health magazine that he almost blew his chances with the musician with his clumsy chat-up line.
“She said, ‘Hi, I’m Britney,’ and I said, ‘I’m sorry, what’s your name again?’” he said.
“I tried to be funny. I don’t think anybody got it.”
Despite that, the pair hit it off, sparking dating rumours the following month when the 28-year-old actor shared a snap of him and Britney at a restaurant.
Opening up about their relationship the following year for the first time, the Princess of Pop, 40, said in a radio interview: “I found his number in my bag. I was like, ‘He is really cute. This guy is really cute.
“So then I called him, and ever since then, he is just a really fun, funny person.”
Asghari, who is also an actor, has been praised by those close to the star for his support.
“Sam has been an absolute dream come true for Britney,” a source told showbiz site Us Weekly in May 2019. “He is such a positive light in her life.”
He has previously spoken candidly about his feelings for the Toxic singer, telling Men’s Health: “She motivates me more than anyone.
“It’s crazy how I can be humbled by a person like her. If I could be that humble when I’m that high in life, that would be the best thing”.
Britney has previously said Asghari “inspires me to be a better person” and that he “makes me feel like the luckiest girl in the world”.
Asghari also vocally supported the popstar during her legal battle to lift her conservatorship, the complex legal arrangement in which Britney’s father and others controlled many aspects of her finances and personal life for 13 years
He wore a Free Britney t-shirt ahead of one of her court appearances, posting a snap of him wearing the tee alongside a lion emoji – a reference to his nickname for Britney, lioness.
Asghari proposed to the Womanizer singer in September 2021, after four years of dating. The pair announced the news on Instagram, with Britney showing off her sparkling diamond ring.
The singer was previously married to her childhood friend Jason Alexander for 55 hours in 2004, and backup dancer Kevin Federline from 2004 to 2007.
She has two sons with Federline, Sean, 16, and Jayden, 15.
Britney Spears through the years