One story you may have heard is about a baby being born “in the caul.” This means the baby was born with his or her face and head, and sometimes torso, covered in a thin membrane from the amniotic sac.

A very rare situation is when the caul is made from non-amniotic tissue. This type can leave scarring on the baby if the membrane isn’t removed slowly and carefully. Another variation is for the baby to be born completely encased in the amniotic sac. This event is called being born “en caul” and, although it seems more extraordinary, is more common than caul births.

The amniotic sac is also known as the bag of water because that’s basically what it is. It surrounds the baby, placenta, and umbilical cord and is filled with warm fluid. The amount of fluid it holds increases as your baby grows. Having too much (polyhydramnios) or too little (oligohydramnios) fluid can cause complications.

In this c-section birth, the little guy was taken out in a complete full package. Years later, Dad reports that he’s doing perfectly well! (And is one lucky guy — naturally). (Image via Tech Boys)

This photo, taken by Leilani Rogers, was one of the best photos of the year, according to The International Association of Professional Birth Photographers. (Image via Leilani Rogers, Photographer)

“Sometimes, babies are born en caul — what’s so scary about that?!” says photographer Lacey Barratt. “I believe too many mums suffer the repercussions of artificial rupture of membranes instead of letting them birth how their body leads them to.” (Image via Australian Birth Photography)

Photographer Daniela Justus had never captured a triplet birth before – so the extra rare moment when baby number two was delivered made it even more special. All three babies, Cecilia, Pedro Henrique, and Isadora were born safely, but when Pedro came out second he was born in the sac, also known as ‘en caul’. (Image via Daniela Justus Photography)

Just moments after birth, photographer Lynsey Stone caught the exact time when the midwife began to peel the membrane off the newborn. (Image via DFW Birth Photographer)

Immediately, the midwives began to peel the membrane off the newborn, as doctors suggest should be done. (Image via One Tree Photography)

This photo, captured by Ashley Renee of Beautiful Beginnings Birth perfects gets the baby’s face. It’s still wrapped in the membrane and has yet to be punctured. (Image via Beautiful Beginnings Birth)

Before this little one was able to be held by his parents, measured, and checked, the doula photographer snapped this gorgeous photo. Membrane intact, still blissfully rounded, the baby had yet to realize it had arrived! (Image via Australian Doula College)

This shot is beyond amazing and touching. Just look at the amniotic sac still halfway intact. (Image via Melissa Cate Photography)

A picture of a baby born “en-caul”, which means that the membrane protecting the baby’s body and head has not yet torn. Normally, this membrane breaks as the birth process commences, and that is commonly referred to as the “breaking of water”.