Immersion in water is but a small part of the potential benefit that a simple pool of water offers to women in labour.
Birth pools designed and used for immersion in water have elaborately moulded interiors that can be described as an “obstetric chair in a bath”.
The pool dictates the position the mother should be in by placing her in a semi-recumbent posture with hand holds and foot rests to fix the arms and legs.
Mothers are positioned in the classic lying back with legs wide-open position but happen to be immersed in water.
These birth pools typically have very little floor space or room to move.
The seats in these water birth pools are typically tilted backwards.
The mother is immobilised in a position with her pelvis tilted upwards resulting in her pelvic outlet being up to 30% smaller.
This puts pressure on the sacrum which flexes upward, into a curved position that restricts the diameter of the pelvic outlet inhibiting the baby’s descent.
The birth canal is placed in an “uphill” orientation, forcing the mother to push upward against gravity to give birth to her baby.
These seats and moulded fittings greatly reduce the space the mother has to move in and restricts her ability to use the positions most beneficial.
The benefits of labouring in water are largely negated.
The possibility of a physiological labour and natural birth is greatly reduced.
By contrast the Active Birth Pool gives mothers plenty of room to move with an unobstructed floor area that measures 1200 x 800mm.
A water birth pool should have features and design elements that support the mother as she changes position rather than dictate the position she is in.
On land women have to contend with the force of gravity that limits their ability to assume upright postures especially as labour progresses and it becomes too difficult to maintain these positions for long.
The buoyancy of water supports the mother allowing her to explore the full range of upright positions with ease and move with renewed energy in ways that were not possible on land.
Mothers experience maximum advantage of the benefits that water offers to help increase the likelihood of a physiological labour and natural birth.