Part of the amnion which covers an unborn baby in the uterus and contains the amniotic fluid.
For the sac of amniotic fluid surrounding the fetus during pregnancy.
A watery, membranous sac that envelops the fetus within the womb. During the onset of labor, this sac located in front of the baby’s head serves as a cervical dilator. It is also referred to as the amniotic sac.