Water seems to relax the body muscles and the relaxation reduces the pain.
The water helps the future mother to be in a pressing position for longer time than she could normally endure.
A gentle start for the child:
To be born in water is a gentle start for the child who is given a little more time before it will start breathing. Waterbabies cry less after birth.
Stay and birth in water:
Many pregnant women choose to stay in water during the birth because it feels good. The warm water seems relaxing and pain relieving and it also provides more freedom of movement. Often labours tend to be shorter and the contractions become more efficient. Also it can influence whether the woman has less tearings.
The water helps to a better birthing positions:
The water in the pools helps the woman to find more ergonomically correct birthing position, and at the same time the warm water is powerfully relaxing the muscles and thus pain relieving. This relaxation and pain relief often result in a shorter and easier labour.