Viewer discretion is advised. A video from a Spanish hospital captures the moment a baby is born within the amniotic sac, an occurrence that only happens 1 in every 80,000 births. It is also known ...

The chorion lies closest to the placenta. The chorionic sac encompasses the fetus and ... containment of the amniotic fluid, and secretion of substances into the amniotic fluid.

Di-di twins are like roommates with their own room and fridge. They each have their own placenta and amniotic sac – and because they don't share as many resources, they have a lower rate of ...