On Sunday, to celebrate the occasion, the pancake chain posted a photo of a fake sonogram featuring a large stack of pancakes topped with butter instead of a fetus.
"If you have pancakes in your tum tum, does that make you a pancake mum mum?" the post read. "Happy Mother’s Day to ALL the moms out there!"
The post, which garnered 1,126 retweets and around 6,300 likes by Monday morning, drew ire in the form of memes, gifs and critical replies from several dozen Twitter users.
Some even called for whoever concocted the marketing gimmick to be fired.
IHOP's social media posts often coincide with the theme of the day.
On Cinco de Mayo, the restaurant chain posted a photo of a blindfolded woman gearing up to hit a giant pancake stack-shaped pinata.
The restaurant even got into the spirit for the season 8 premier of "Game of Thrones."
A spokesperson for IHOP did not immediately respond to ABC News' request for comment.