It's a moment most parents treasure, their first proper glance at their unborn child.
However, for Sophie Nagle, 25, from Reading, seeing her son, Reuben, in the womb left her feeling 'freaked out' - after he flashed a sinister-looking smile.
The mother-of-two says the black-and-white image left both her and the scan technician startled by the Joker-esque smile as the camera caught the baby face-on.
Sophie said even the ultrasound technician was confused by the strange-looking snap, which she recently shared online as she hoped other parents might have been through the same experience.
The 25-year-old said the spooky snap even put her off having further 3D scans but luckily little Reuben's smile has grown much more angelic.
The stay-at-home mum said: 'I was a bit freaked out the first time I saw Reuben's scan, because I'd never seen a scan with the baby facing the front.
'I was going to get a 3D scan too, but after seeing this one I decided against it.
'Even the lady doing the scan was shocked.'
Mums-to-be undergo routine scans at eight to 14 weeks, and then between 18 and 21 weeks of pregnancy to ensure the foetus is developing healthily.
Reuben, now two, was born last year but Sophie only recently rediscovered the snap this month when she took to social media in a quest to find other parents who had experienced the same thing.
The ultrasound scan, taken in 2016 and first posted last week, clocked up hundreds of shares and divided commenters between those amused and those frightened by it.
But luckily, recent images of Reuben show he still has a penchant for smiling - albeit in a much more angelic way.
Sophie said: 'I remembered it the other day and decided to check if anyone else had seen anything like it, but nobody had.
'I was pretty amazed with how far the picture spread. I think some loved it, but others were quite creeped out.
'Other mums were sharing their own examples, but there were none smiling like this.'