Baby born still INSIDE his amniotic sac is hailed a 'medical miracle' by doctors

His hands and feet were clearly visible - but baby Silas Philips was in no rush to enter the world.

Born still inside his amniotic sac, he has since been described as a 'medical miracle' by doctors. 

Silas was delivered three months prematurely at the Cedars-Sinai Medical Center in California.

And doctors performing the Caesarean section on his mother, Chelsea, were astonished to see his amniotic sac was still intact.

Pictures show Silas curled up inside with the placenta and umbilical cord, his tiny hands and a leg clearly visible.

And until the bag was broken, he was still getting oxygen through the placenta, CBS reported.

The amniotic sac is a bag of clear, pale fluid inside the womb where the unborn baby develops and grows.

The fluid helps to cushion the baby from bumps and injury, as well as providing it with fluids it can breathe and swallow. It also maintains a constant temperature for the baby. 

Typically the amniotic sac breaks on its own during birth, which is commonly referred to as a mother's 'water breaking'.

Or during a C-section, the surgeon cuts through it to deliver the baby. 

Doctors say the chance of the amniotic sac remaining completely intact after birth is 'ultra rare'.

It was a moment that mesmerised Dr William Binder, who delivered Silas.

'Even though it sounds cliched, we caught our breath,' he said. 'It really felt like a moment of awe... and one that will stick in my moment for some time.

Follow NEWS.am Medicine on Facebook and Twitter