On Monday, Aug. 24, Kim Kardashian posted a snapshot of her unusually plump “pregnancy lips” on Instagram, and the entire world (i.e. the Internet) seemed to scream in astonishment.

Rand Rusher RN, a licensed cosmetic nursing specialist, told Us Weekly that plush “pregnancy lips” may and do occur in certain women.

“During pregnancy, hormones can cause fluid retention, which leads to increased swelling,” Rusher told Us. “This can occur in different parts of the body, including the face. It’s a common occurrence.”

However, while Rusher, who also has his own high-end medical apparel brand called Stitch Lab, acknowledges that “pregnancy lips” are possible, he also points out that they don’t stay forever. “The lips usually go down after birth, but can take up to six weeks to go back to the original size,” he explained.