''Waters'' refers to the amniotic fluid that surrounds and protects the baby in your womb throughout pregnancy. The waters are contained in membranes and when these pop, the waters leak or gush out. In normal labour it is the membranes bulging through the opening cervix that causes the pressure which bursts them. Sometimes during labour if they do not break spontaneously, your midwife/doctor may want to do this to encourage labour progression by performing an ARM (artificial rupture of the membranes).