Carole Thorpe, an amazing Hypnobabies instructor in California put this together. (It explains it perfectly)
The most common misconceptions about Hypnobabies Childbirth Hypnosis are, that hypnosis is merely another method of coping with pain, or that it's pain management, or that hypnosis is just flowery guided imagery delivered in a monotone voice that induces deeper relaxation than other methods, or that hypnosis distances a woman from her body during her baby's birthing and denies her basic physiological responses that others create through enduring pain, or that women won't remember their baby's births, or that moms must lie still and listen intently to hypnosis recordings... their birthings entirely scripted, for hypnosis to be of any use. None of these assumptions are true of real self-hypnosis, deepened to the level of 'somnambulism', which is the depth of hypnosis that one must achieve to create an anesthesia effect in the body.
When a birthing woman is profoundly relaxed and deeply in a state of self-hypnosis, she responds to pre-programmed, post-hypnotic suggestions so profoundly that her body creates endorphins, seratonins, melatonins and other relaxing hormones and stress-reducing brain chemicals. This happens automatically and all the smooth muscles in her body, all the muscles controlled by the autonomic nervous system relax so powerfully, that a physiological response occurs that is perceived by the woman as a lessening of physical sensations, or a profound diminishing of discomfort, and for the majority of them...the elimination of pain entirely. Hypnotherapists call this phenomenon, "hypno-anesthesia".
It's common knowledge among those who teach clinical hypnosis for medical purposes, that hypnosis can slow a person's pulse and respiration rates, and lower blood pressure, and eliminate pain entirely. Doctors and dentists use this type of hypnotic conditioning with their patients to create "hypno-anesthesia" for their patients who are allergic to medical anesthesia. These doctors and dentists perform surgeries with no medical anesthesia, with no pain and no side-effects.
Hypnobabies eyes-open childbirth hypnosis teaches the same medical self-hypnosis techniques that doctors and dentists use for their patients who cannot have medical anesthesia. Women listen to hypnosis scripts to learn a cue to instantly enter self-hypnosis, and how to deepen it to the level of somnambulism in order to create an anesthesia effect in their bodies. Hypnobabies mothers experience their contractions as "only pressure" or a bearing down sensation, or even like being squeezed or hugged tightly. Many Hypnobabies moms have described the sensation of their contractions as being very much like the sensation of a tight blood pressure cuff...intense, even sometimes mildly uncomfortable, but not automatically painful.
Hypnobabies moms learn to create hypno-anesthesia at the drop of a finger, literally. They learn to deepen their ability to do so by listening to a script designated to this purpose. Then with practice and by listening to other scripts, these women learn to strengthen the effects of this hypno-anesthesia in their bodies. They regularly practice scripts with their birth partners during their pregnancies to instill these skills as an automatic response to the sensations of their contractions when their labor begins. Through repetition and the resulting compounding effect, Hypnobabies moms learn to do all of this with their 'eyes open' so that they can move around and respond to their birthing body's cues and their baby's movements.