Justin Bieber posts Hailey Baldwin 'pregnancy' pics on April 1

Justin Bieber has taken to Instagram to suggest his wife Hailey Baldwin is pregnant, on April 1 in the US.

The 'Baby' singer posted the ultrasound photo that comes up on Wikipedia when you search the word "ultrasound", before publishing a second of Hailey posing in what appears to be a medical facility.

"If you thought it was April Fools," Justin captioned the second photo, which is staged to depict Hailey being attended to by two medical staff with an IV drip attached.

Although the photos clearly look like an attempted joke, comments from many fellow celebrities and fans show they appear to have fallen for it - or are playing along.

Fake pregnancy announcements for April Fool's Day have come under fire on social media lately, with many health professionals warning they're far from a harmless gag.

A post has been widely shared over the past 24 hours, highlighting statistics of miscarriage and infertility.

It shows a pregnancy test with the words: "This is not an April Fools Joke! One in four of your friends will have lost a baby and one in six will be suffering with infertility".