The first-ever winner of the U.S. talent show is expecting her second child, and has been open about how her severe morning sickness has affected her ability to make public appearances.

And before she welcomes a baby boy this spring (16), Nashville, Tennessee-based Clarkson is heading back to Los Angeles to serve as a guest judge on American Idol for its 15th and final season, a decision which was both easy and difficult for her to make.

"I was going to do the Grammys and Idol... but I just have such hard pregnancies, flying back and forth to L.A., like if they were closer together, I would’ve done both, but I had to kind of choose one," she tells Houston, Texas radio station 96.5. "I obviously chose Idol because it’s ending and I was the original winner, so it’d kinda be weird if I wasn’t there.

"I’m unfortunately going to have to miss the Grammys, because my doctor was like ‘Yeah, that’s not too smart for you...' I was pretty bummed I’m gonna miss the Grammys this year."

Clarkson is set to join judges Jennifer Lopez, Keith Urban and Harry Connick, Jr. during this season's first live show, which is scheduled to air in the U.S. on 25 February (16). The 2016 Grammy Awards will be held 10 days before on 15 February (16).

The singer first became a mum when she and talent manager husband Brandon Blackstock welcomed daughter River Rose Blackstock on 12 June, 2014.

kelly announced her second pregnancy during a concert in Los Angeles last summer (15).