Couple fools family about baby's gender after sonographer screw up

A US couple has filmed the heart-warming moment they revealed the gender of their newborn son to the baby's shocked grandmother after she had been led to believe they were having a girl.

Kyle and Danielle Williams, who already have a 2-year-old daughter named Peyton, had been told by their sonographer they had a baby girl on the way.

"We were told it wasn't the best picture when the sonographer printed it for us, but she assured us she saw at the very beginning of the ultrasound that it was in fact a baby sister for our daughter," Mr Williams told Inside Edition.

The couple then picked out a name, Charlee, for their new baby girl.

But when Danielle Williams gave birth on March 3, they were shocked to find the new arrival was a boy.

"You're there thinking, 'here she comes. Oh, wait, it's not a she'," Mr Williams said.

"I kept looking back and forth to my wife, not saying anything to her. She frantically asked me, 'What's wrong? What's wrong?' and all I could say to her was, 'Well, there's a bit of a surprise.'"

They then decided to keep it going, allowing Mr Williams' mother to discover their newborn was a boy on her own as she changed the baby's nappy.

"Oh my goodness!" she exclaimed, having loaded up the couple with pink clothing before the birth.

"You guys are not joking!"

Pregnancy expert Dr Lisa Masterson said getting the baby's sex wrong is more common than people realise.

"There are multiple things that factor into the accuracy of the ultrasound. The fluid that's around the baby, because there's less fluid then everything is kind of squished up and you can't delineate all the borders," Ms Masterson said.

"(There is also) the position of the baby. If the legs are crossed and you can't really see if there's a penis or not."

Source: Inside Edition