It is a fluid in the uterus surrounding the fetus.
It consists of fetus urine, maternal serum fetal cells , near birth – amnionic volume will be 500-1000 ml. If the fluid is excess (>2000 ml) it is called as Hydraminos. If less it is called as Oligohydramnios .
· It allows for growth and free movement of fetus.
· It protects the fetus, acting as shock absorber.
· It maintains an even temperature for fetus.
· It prevents pressure on the cord.
· It acts as cushion around the fetus, because it protects the fetus from injury, if mother is bumped or falls.
· It is a fluid source that the fetus drinks and then urinates.