So the AMN is that sac, the fluid filled sac that contains that developing embryo and that developing fetus. And so what happens towards the end is it ruptures, releasing about one liter of amniotic fluid through the vaginal cavity and into the outside environment. And so this is when that woman knows she's at the end of stage one. Now, what about stage two? Well, stage two is the actual birthing process. This is when the woman actually pushes.