Why Justin Bieber's April Fools' pregnancy Instagram post wasn't a smash hit

Beliebers everywhere were stunned when Justin Bieber posted an photo of an unborn baby in a sonogram photo to Instagram on Monday. The post, which had no caption, sent fans into a tailspin.

Given the date of the post -- April 1st -- and the fact that the sonogram photo appeared to be taken from Wikipedia, plus the fact that wife Hailey Baldwin commented "very funny ...", all signs pointed to a bad April Fools' joke.

The initial post was followed by two more: One of Baldwin in what appears to be a doctor's office and then a sonogram photo with a puppy superimposed on top.

Bieber has come under harsh criticism since the post. Many commenters feel infertility and pregnancy are not a joking matter, given the number of couples who struggle with infertility. According to the Centers for Disease Control and Prevention, approximately 12 percent of women, ages 15 to 44, have had difficulty getting pregnant or carrying a pregnancy to term.

Last year, ABC News covered the story of woman whose viral Instagram post on why pregnancy-related April Fools' Day jokes are not at all funny. Chelsey Cardinal now has children, but struggled to conceive.

"People don't understand that the pain of infertility doesn't disappear just because you have children," Cardinal said. "Looking back on it now, I used to hold so much anger at those posts. Now I look at it as an opportunity to educate people," she told ABC News in 2017.

Experts agree.

Sonya Frazier, a licensed mental health counselor based in Tampa, Florida, told ABC News that it's important to "be mindful of the implications" of jokes and pranks on April Fools' Day.

"Words do hurt," she added. "And infertility is still much of a personal and private experience for many women and men. To joke about such a topic could potentially trigger a stream of negative emotions in those who are trying to conceive."

Joi-Marie McKenzie contributed to this report.