Meghan Trainor has launched her six-week countdown to motherhood by posting a shot of her bare baby belly.

The All About That Bass singer marked "6 weeks to go" on Sunday night by posting a glamour shot of herself wearing just a white shirt which had only been buttoned up at the breasts. In the snap, she can be seen cupping her bump to protect her modesty.

The photo received praise from her celebrity pals in the comments, with Nicki Minaj simply posting an emoji of a face with heart eyes and Nicole Scherzinger writing "angel".

TV personality Maria Menounos also commented, "What?! How the heck does time fly so fast?! For me at least hahah for you I’m sure it’s different (laughing emoji)."

While promoting her holiday album, A Very Trainor Christmas, in October, the 27-year-old singer told Billboard her first pregnancy had been eventful.

"My bump, sometimes is, like, humongous and then some days, I'm like, 'Yeah, we're just normal'... but some days, just, like, large," she laughed. "And when I'm walking, I'm starting to wobble, and my ankles are swelling up. But it's exciting stuff! And when he's (baby) kicking me all night, I'm like, 'What's up!'"

Trainor and her husband, actor Daryl Sabara, are expecting their first child next month.