exerts pressure on the mother's sacrum.

Another prominent sign of labour is the rupture of membranes, commonly known as "water breaking". During pregnancy, a baby is surrounded and cushioned by a fluid-filled sac (the amniotic sac). Usually, the sac ruptures at the beginning of or during labour. It may cause a gush of fluid or leak in an intermittent or constant flow of small amounts from a woman's vagina. The fluid is