An Introduction to Birthing Hormones
For all the birth geeks out there, here are a collection of my findings on the the endocrine aka hormonal system at and around birth. Unlike the nervous or cardiovascular systems, it cannot be physically "seen" in the same way. Hormones, from the Greek word to "excite" or "set in motion" are released by glands and organs throughout the body in order to send messages, like how nerve impulses do, but differently.
They control our blood sugar levels, our sleep patterns, our menstruation, sexual attraction i.e pheromones and birth. They really are intrinsically magical.
I want to introduce some of these magical hormones that we know are present in labour and the immediate period afterwards and explain what they do and tips to enhance their positive effects and how to inhibit their negative ones.
Firstly lets briefly discuss your sympathetic and parasympathetic nervous system...
Sympathetic nervous system is your bodies quick nervous and hormonal response to a perceived dangerous and/or stressful situation. It's what keeps us alive. Think about when you've witnessed a aggressive brawl whilst out, or if you see crowds of people running in one direction in a street. Your body immediately becomes alert and you become ready to run and get out of harms way. This is commonly known as our "fight or flight response". Hormones flood the blood stream sending a quick message to increase heart rate to prepare for physical activity.
The Parasympathetic nervous system is the yin to the yang, It works in contrast and is the body's ability "rest and digestion" and associated with growth. It's lesser known, but more often seen. These hormones make us relaxed, at ease especially when bonding and present during feeding. It slows heart rate and breathing, allowing our bodies to increase digestion potential, thus growth potential. It counteracts the sympathetic nervous, e.g. skin-to-skin or breastfeeding after birth calms both baby and mother.
The What/Where/Why of Birthing Hormones
Beta-endorphin
Secreted in pituitary gland in brain, this hormone is for pleasure and transcendence (people often talk about this effect after exercising). A naturally occurring opioid pain-killer, increases euphoric feelings. It’s released in reproductive activities like sex, breastfeeding and birth. It reduces effects stress peaks at time of birth and for those who have had an undisturbed birth, higher levels are found in breastmilk
Oxytocin
Secreted in pituitary gland in brain, known as the “love drug/hormone”as it is present during sex, at time of orgasms, birth and when breastfeeding.
It’s even present when we socialise with one another, like sharing a meal. Receptors on the womb lining increase and reaches it’s peak at time of birth. Another natural opioid pain-killer and causes womb to contract and lead your baby down, causing more contractions. Known as Ferguson Reflex
Natural oxytocin is released during skin-to-skin after birth causing further womb contractions that’s lead to birth of placenta and reduces risk of haemorrhaging. It’s needed for milk let-down and apart of the parasympathetic nervous system, therefore inhibits the “fight or flight” response. Therefore stimulating the “growth and digestion”response, which makes maternal digestive system become more efficient in preparation for supporting 2 lives.
Prolactin
Secreted in pituitary gland in brain and known as the “parenting hormone” as its involved in milk production and "nesting". It increases throughout pregnancy, preparing breasts for baby and lactation. It’s said to “re organises” mothers brain in preparation for motherhood. It’s inhibited by progesterone, which is released by the placenta, so as soon as that is birthed, the prolactin levels soar within the first hour
Just holding a baby can produce higher prolactin levels which is why fathers are known to have elevated levels, in fact fathers with elevated levels are known to be more responsive to newborn cries.
Catecholamines
This hormone is produced in the adrenal gland in the brain and is apart of the sympathetic nervous system “fight or flight” response. The body produces it in response to;
fear (not knowing what is going to happen/who people are in the labour room/of how their baby is doing etc.)
hunger (being nil by mouth)
bright lights (labour room/theatre strip lighting) Sleep/eye masks are perfect for limiting views and light.
cold (labour room temperature, draft)
excitement (transitioning)
Catecholamines levels slowly rise during labour and if undisturbed should peak when the labouring person transitions (this is when cervical dilation makes way for baby’s descent), characteristics of the person changes and it’s due to this hormone. Earlier in labour, the presence of this hormone can cause womb contractions to slow down or stop altogether (think about when a person has been moved from one room in labour to another).
High levels of catecholamines in early labour is associated with the person perceiving danger in someway and nature responds by restricting blood flow to the womb and placenta to keep their baby out of danger. High levels are also associated with longer labours and concerning fetal heart patterns
High levels at the end of labour (if the early stages had low levels and was undisturbed) are vital to the birth baby and make the labouring mother alert, energetic and focused and this is what is witnessed in transitioning. It works with oxytocin in the Ferguson Reflex to give the labouring person a strong, uncontrollable urge to birth their baby
After birth high levels reduce, keeping the person and baby warm will help this. If not it can inhibit oxytocin’s ability to contract and stem bleeding. Babies are also effected by catecholamines, it prepares them for life outside as it;
increases baby’s ability to produce glucose and fatty acids to prevent hypoglycaemia once they’ve been removed from the placenta
stimulates lung surfactants
assists with their ability to keep warm
regulates their breathing
improves their tone responsiveness
assists their heart functions
This is why babies who have had an undisturbed birth are often wide eyed and alert in the first hour. Levels drop soon after, especially after skin-to-skin. catecholamines helps assist with the sense of smell, so they can recognise their mum (which is why it is so important to swap muslin cloths from both mother and baby if they are separated for medical reasons)
Catecholamines are released in the pineal gland in brain, it’s known to regulate circadian rhythms, which is our sleep-wake cycle and thought to be the reason why most labours start in the middle of night/early in morning, this makes evolutionary sense to keep births away from possible predators (think Saber-Toothed Tiger)
Relaxin
Is produced by ovaries and the placenta, it does exactly what it says on the tin, it relaxes and softens ligaments and helps cervix to dilate. Also allows for hips to be more flexible allowing baby to rotate down and movements to be easier.
Cortisol
Is thought to make maternal instincts heightened and them more attentive and increases their fondness to the smell of their baby and helps mature baby lungs, which is synthetic cortisol is given to pregnant people whose babies are predicted to be born early for this reason.
As you can see, it’s quite the mix and blend of hormones. All dancing together, ebbing and flowing to safely bring your baby into this world. Having bright lights on or a stranger present in the birthing space (yes, that includes a healthcare professional) can have ramifications on the process and progress of labour, I’ve seen it happen countless times, which is why I often suggest bringing a pair of dark sunglasses or sleep-mask into hospital environments when in labour.