If the movie industry were to be believed all births start with the mum's waters breaking. But while it doesn't always happen quite so dramatically, more often than not, the amniotic sac does breaks when a woman goes in to labour (or at some point during her labour).
But, it is possible for a woman to go through labour with the amniotic sac intact as this incredible footage shows.
The baby was born via caesarean section and remained cocooned inside the amniotic sac completely unaware of her new surroundings.
The footage was posed on to Facebook page Birth without Fear this week where it has been viewed more than 1.2 million times and received thousands of comments.
These sorts of births are known as caul births and are thought to be a good omen.
Since posting the footage, Birth without fear has shared another post about caul births and says that it could be a more common phenomenon than previously believed.
"We are amazed by how more common babies being birthed en caul is happening and being captured on film. Still amazing every time," they write along with a photo of another caul birth.
Some mums have taken to the comments to share their own experiences of caul birth.
"My third son was born en caul...though it burst before he came all of the way out (I'm pretty sure). Usually we don't find out the sex beforehand, but that time we did and had already picked out the name Asher, which means happy or blessed one, and in some cultures being born en caul signifies a special blessing, so that was kind of neat," wrote one mum.
"My son was born en caul. My midwife didn't break my water thinking it would on it's own. Such a cool experience!" said another.
"My daughter was born like this," wrote one mum. "Simply amazing."