Hormones in Labour
(adapted from an article by Michel Odent)

We know that in order for a woman to give birth, she needs to release a certain number of hormones such as oxytocin, endorphins, prolactin, adrenocorticotrophic hormone, and catecholamines.

The important point is that all these hormones originate from the same gland—the brain. It is essential to stress that it is not the whole brain that is active as a gland, but only the old structures we share with all the mammals (hypothalamus, pituitary gland, etc.).

We might say that when a woman is in labour, the most active part of her body is the primitive brain. Modern physiology could also explain that when there are “inhibitions” during the birth process (or for that matter, any sexual experience) such inhibitions originate in the new brain: the neo-cortical structures that support the intellect.

Physiologists could explain a phenomenon that is well known by mothers who have the experience of unmanaged and un-medicated births. During the birth process there is a time when the mother behaves as though she is “on another planet,” cutting herself off from our world and doing a sort of “inner trip.” This change of conscious level can be interpreted as a reduction of neo-cortical activity.

Midwives and doulas who have understood this essential aspect of the physiology of labour and delivery avoid any unnecessary neo-cortical stimulation that can interfere with the progress of labour….

Any situation associated with a release of hormones of the adrenaline family also tends to stimulate the neo-cortex and therefore to inhibit the birth process.

This means that a labouring woman needs first to feel secure. This feeling of security (and relaxation) is a prerequisite for the change of level of consciousness that characterizes the birth process.

Michel Odent.