The Four P’s of Pregnancy
Most of us are led to believe that the size of our pelvis and the size of our baby are the two factors that determine our body’s ability to birth our baby vaginally. Those may play a role, but there are SO many more factors at play, and in most cases, your body (and your baby’s body) are on your side to help birth baby!
If you’ve followed along in our text thread, you' have the first 3 P’s (but don’t worry, there’s a recap of those at the bottom in case you want a reminder, or if you missed any of them). But the fourth P was too wordy and FAR too important for me to cram it all in to a text. So let’s chat here about the fourth P: PSYCHE
Yes, birth is very physically challenging, but I truly believe that it’s much more a mental game than it is physical. Your mentality around birth- and all of the challenges along the journey of the birth process- can be changed for the better or the worse by how you feel about birth mentally.
“When you change the way you perceive birth, the way you birth changes.”
- Marie Mongan
First, let’s chat about STRESS HORMONES, specifically catecholamines. These stress hormones are beneficial at certain times- for example, when baby is born, they help to regulate breathing, heartbeat, blood pressure, and energy metabolism. However, if you have high levels of catecholamines early in labor, they have the potential to stall or stop labor. 😬
In the wild, a fear of predators will cause the laboring mother to release these catecholamines- which effectively “shuts off” labor so that the mama can move to a place of safety before birthing her baby. And while we aren’t worried about lions chasing us during labor (or at least I really hope you aren’t! 🦁), our body will release catecholamines whether there is a REAL, POTENTIAL, OR PERCEIVED threat of safety. Think: fear of pressure for unwanted interventions, your mother-in-law who pressured you into allowing her into the labor room, the pushy nurse who reminds you often that something could go wrong at any moment, the beeping from the monitor that makes you think there actually is something wrong…all of these things can create a release of stress hormones. So setting up your space (including the people around you) to create a profound sense of safety should be a high priority for you!
Another thing to note: There is something called the fetal ejection reflex, which basically means that your baby WILL come out- your body will make it happen. This is an involuntary process. However, when studied on a group of mice, simply disturbing the mice during labor (especially by a lack of privacy), the mice experienced catecholamine surges, and labor would shut down in early labor. Later in labor, this hormone release was inhibited and the fetal ejection reflex did not occur. This helps affirm that requesting minimal interruptions (from both birthing staff, as well as family/friend visitors) is absolutely a good idea.
Next, when we consider the nervous system’s role in stress management, having a nervous system that is already geared toward that fight-or-flight response (which most of us are, unless we are intentional about not being that way). This is a big reason why I will always be an advocate for getting adjusted throughout pregnancy, and even a bit extra in the weeks or days leading up to birth.
It’s also important to consider your fear around birth. Have you been strongly influenced in your perception of birth as a result of birth stories you've heard from close family and friends? Do you have your own previous birth trauma you’ve experienced? Has your prenatal provider communicated in a way that has cultivated fear around the need for interventions or just the inherent nature of “anything can go wrong” surrounding birth? Furthermore, while YOUR psyche is the most important, the psyche of all the other people in the room (or close to you throughout your pregnancy) can also impact the progress of your labor! If you have other people (both providers, as well as your chosen support system) around you who have an inherent fear of birth, they can easily begin to panic when the going gets tough, and this can negatively impact your stress during labor. So ensuring you have the right team of people around you is vital! It’s also a reason I’m a big fan of doulas, as they are great at helping support you in seeing what’s going right (instead of what’s going wrong) and helping you navigate the challenges of labor without being fearful about it.
Beyond having a doula and supportive people in the room, the other things you can do to create a perception of safety during your birth: minimal interruptions, dim lighting, music that relaxes you or brings joy, birth affirmations, having a birth plan (that you’ve communicated about with your provider ahead of time), calming or uplifting essential oils, and having read through positive birth stories.
And for a recap of the first 3 P’s:
The first P that influences the progression of labor: PASSENGER (aka the baby or babies) But that doesn’t just mean baby’s size. It also means:
Their position (head down? engaged with cervix?)
Their size (but remember that the ultrasound is an estimate, and often reported as larger than reality)
How many are there?
Your baby HELPS during labor in these ways:
Their cranial bones are in fragments, and will overlap as they come through the birth canal- so the head circumference you see at birth is not the full size of what comes through your pelvis
They kick off the top of your uterus to help bring themselves down
They rotate their body through your pelvis as they descend
The 2nd P that influences the progress of your labor is PASSAGEWAY- aka your bony pelvis and your cervix.
Remember that your pelvis will flare open as baby descends. This is an IMPORTANT reason to be getting adjusted all the way up to birth, as we ensure your pelvis is nice and freely moveable (aka no stuck points)
Staying upright in labor and moving will help allow baby to shimmy down through your pelvis
Cervix readiness is a big factor in labor progression. While there are things you can do to encourage labor to start, I would urge you to allow your body to ready itself. Trying to stimulate contractions without a ready cervix will just cause you get worn out from contractions before everything else is even ready to get going.
The 3rd P that influences the progress of your labor is POWER- aka the power of a contraction. This is heavily influenced by the 4th P (more on that later), but here are some notable things on how you can help the POWER: It is primarily involuntary, controlled strongly by the nervous system's control of uterine muscles (this is a great reason to be getting adjusted, to keep the nervous system balanced). At the end, your body will have a fetal ejection reflex- this is where your body will begin to push even if you aren't actively attempting to push. (I have experienced this myself, and can attest that it resulted in a GREAT birth- less than 10min of pushing!) Keeping your body fueled with food and hydration in labor helps to supply these muscles RESTING as much as possible before labor, as well as between contractions helps to allow each contraction have lots of "umps" behind it. Having a pelvic floor that is relaxed enough to get out of the way helps to get the most out of your power!