Phys-i-o-log-i-cal: Characteristic of or appropriate to an organism's healthy or normal functioning.
Do you call a doctor every time you need to go to the bathroom? Of course not! That would be silly, since going to the bathroom is a physiological process that, unless your body is diseased or imbalanced, happens naturally. It's healthier if your body can complete this process without interventions or medications. We don't call the doctor or interfere with our body's natural process unless we encounter a problem.
The birth of a baby is a normal, physiological process of the body, and of all mammals. Just as the human body knows how to enact immune response or eliminate waste, your body does not have to be told how to give birth. Just as a woman's body knows what to do when an egg is fertilized and a baby is grown within her womb, it also knows when and how to birth that baby into the world.
What is Physiological Childbirth?
Physiological childbirth simply means birth in it's most natural form, without intervention or medications. The mother is allowed to labor how and where she wants, and birth is left to happen naturally. The definition can also be extended to the postpartum time.
A physiological birth is spontaneous in onset; The mother chooses her location, is given freedom of movement throughout labor, and chooses the birthing position. There are no routine interventions and no separation of mother and baby after the birth.
How Mammals Give Birth
In all mammals, including humans, labor and birth are brought about by a cocktail of hormones (called love hormones) which include oxytocin, endorphins, prolactin, and vasopressin. Anything that interferes with the production of these hormones can stall or even stop labor altogether.
Adrenaline, an emergency hormone, is especially detrimental to the production of “love hormones”. We release adrenaline when we feel unsafe, observed, or too cold. In order for the body to best perform during labor and delivery, a mother must feel secure, unobserved, and be in a warm enough environment.
Read more about humans and mammal birth at WombEcology.com
Why is Physiological Birth Important?
Interfering with a normal, healthy birth process can cause more harm than good. Have you or someone you know ever had difficulty going to the bathroom in public? If so, you have witnessed the effects intervention can have on a physiological process. Some individuals, when under stress or unable to find a comfortable environment, will “hold it”, causing major issues with constipation.
The same can be true of birth. This is not the case for every woman in labor, but the majority of women need privacy. Birth is an intimate act that we perform with our sexual organs. Just as we wouldn't feel comfortable inviting the world to observe the intimate acts that created our baby, we shouldn't feel forced to let a group of strangers observe our labor and birth. Doing so can cause a particularly self-conscience or “shy” mother to hold back, and not allow herself to relax enough to give birth as easily as she would in a private environment.
The same is true for other interventions and medications. There is sometimes pressure to “speed up” the labor process by various means, but each intervention inevitably comes with consequences, however small.