"I don't mind if it's a boy or a girl, as long as it's healthy," is a mantra often repeated by mums and dads-to-be.
The look on this new mum's face sums the feeling up perfectly:
"The priceless look on a mama's face who was told she was having a baby girl but received a baby boy," wrote Jes Jackson, a birth photographer from Tasmania, Australia, who captured the moment of shock.
"Talk about a big surprise! Anyone else get a surprise like this at birth? Shared with permission by the parents."
Mum Koto Nakamura and her husband, Sina Niakansafy, had planned to name their baby daughter Hinata.
"I thought everyone was joking," Nakamura told TODAY Parents. "I lost words and I couldn't believe it until I saw his bottom."
"I was shocked for a few seconds, and then it didn't matter if it was a girl or a boy."
The couple named their son Taiga.