Nurse captures incredible video of baby born inside amniotic sac.

Warning: This post contains graphic images of an amazing birth.

An incredibly rare moment, captured on video,  has been shared by a hospital in Brazil – the moment a baby was born en caul – still beautifully contained in her amniotic sac.

The baby, born on Saturday, just a few minutes after its twin stunned medical staff.

The newborn's twin was born first - without an amniotic sac. Via IStock.

The video was caught on camera and shared by Gisele Correa, a nurse at Santa Casa de Misericórdia de Barretos hospital in Sao Paulo.

She wrote on Facebook:

"It was magic. . Exciting to all team!!! We were waiting to stabilize the first baby and the second came softly, in fact, look there that beautiful!!! Historic moment!!!!"

The chances of a baby being born en caul is so rare it only happens every one in every 80,000 births.

In the video the newborn and its still-attached umbilical cord gives us a rare glance into a medical marvel.

The incredible footage was captured by a nurse.

The baby, perfectly safe, is moving inside the sac as the team of doctors looks on, as its like the baby was still in the womb she continues to receive nutrients and oxygen from her mother via the umbilical cord.

Normally, before birth or during the birthing process this sac would be broken, but in the case of this little marvel doctors had to remove it with a scalpel.

The baby then only can take her first breath of air once her sac is ruptured, the cord is clamped and the medical staff have suctioned out mucus from her nose and mouth.