Imagine this. Your cat is pregnant, due to give birth around the same
time as you are. You have your bags packed for hospital, and are awaiting
the first signs of labour with excitement and a little nervousness .
Meanwhile your cat has been hunting for an out-of-the way place- your
socks drawer or laundry basket- where she in unlikely to be disturbed.
When you notice, you open the wardrobe door, but she moves again.
Intrigued, you notice that your observation- even your presence- seems to
disturb the whole process. And, wish as you might to get a glimpse into
the mysteries of birth before it is your turn, you wake up the next
morning to find her washing her 4 newborn kittens in the linen cupboard.
Birth among mammals:
Why does birth seem so easy and matter-of-fact
to our animal friends when it is so difficult for us? There are certainly
anatomical differences. The altered shape of the pelvis and birth outlet
that is caused by our upright stance creates difficulties, and our babies
need to twist and turn to navigate these unique bends. Even our nearest
cousins, the great apes, have a near-straight birth canal.
However, in every other way, human birth is like that of other mammals-
those animals that suckle their young- and involves the same hormones- the
body’s chemical messengers. These hormones, which originate in the deepest
and oldest parts of our brain, cause the physical processes of labour and
birth, as well as exerting a powerful influence on our emotions and
Researchers such as French surgeon and natural birth pioneer Michel
Odent believe that if we can be more respectful of our mammalian roots,
and the hormones that we share, we can have more chance of a
straightforward birth ourselves.
The hormones of birth:
Labour and birth involve peak levels of the
hormones oxytocin- sometimes called the hormone of love- and prolactin,
the mothering hormone. These two hormones are perhaps best known for their
role in breastfeeding. As well as these, beta-endorphin, the body’s
natural pain-killer, and the flight-or-fight hormones adrenaline and
noradrenaline play an important part in the birth process; there are many
more hormonal influences on birth that are not well understood.
All mammals seek a safe place to give birth. This "nesting" instinct
may be due to an increase in prolactin levels- prolactin is also sometimes
referred to as the nesting hormone- or perhaps to a change in the balance
between the female hormones oestrogen and progesterone that occurs soon
before labour. At this stage,as you may have observed with your cat,
interference with the nest- or more importantly with the feeling of
safety- will stall the beginning of labour.
Even after labour has started, there are certain conditions that will
slow, or even stop the process. If the flight-or-fight hormones are
activated by feelings of fear or danger, contractions will slow down. Our
mammalian bodies are designed to give birth in the wilds, where it is
obviously an advantage to postpone labour when there is danger, and to
seek safety. Many women have had the experience of their labour stopping
when they entered the unfamiliar surroundings of a hospital.
Michel Odent cautions that even hunger, which also causes the body to
release flight-or-fight hormones, can create difficulties with the
establishment of labour. He advises women to eat- if they are hungry- in
the earliest stages of labour; many hospitals have a policy which prevents
labouring women from eating once they are admitted.
Oxytocin- the love hormone: Oxytocin causes the uterus to contract
during labour. Levels of oxytocin gradually increase throughout labour to
peak at around the time of birth, when it is thought to contribute to the
euphoria and receptiveness to her baby that a mother usually feels after
an unmedicated birth. This peak, which is triggered by sensations of
stretching of the birth canal just before delivery, does not occur when an
epidural is in place. Interestingly administration of an epidural has been
found to interfere with bonding between ewes and their newborn lambs.
Synthetic oxytocin is often given by drip- that is, directly into the
bloodstream- when labour contractions are inefficient. Oxytocin given in
this way does not enter the brain, and therefore does not contribute to
the post-birth "high", and in fact can lead to a reduction in a mothers
own oxytocin production by "negative feedback". Nipple stimulation can be
used to improve contractions in labour, because, like breastfeeding, this
causes oxytocin levels to increase.
Oxytocin has another crucial role to play after the birth. Oxytocin
causes the contractions that lead to separation of the placenta from the
uterus, and its release as the "after-birth". When oxytocin levels are
high, strong contractions occur that reduce the chance of bleeding, or
Putting your newborn baby to your breast is the easiest way to increase
oxytocin levels, but Michel Odent also emphasises the importance of
privacy during the hour following birth. This gives the opportunity for
uninterrupted skin-to-skin and eye-to-eye contact between mother and baby
- conditions that optimise oxytocin release. One study showed that mothers
who cuddled and suckled their babies in the first hour maintained higher
oxytocin levels, interacted with their baby more at four days, were more
tolerant to stress or monotony, had lower blood pressure and less body
tension, and breastfed for longer.
Oxytocin helps us in our emotional, as well as our physical, transition
to motherhood. From the first weeks of pregnancy, oxytocin helps us to be
more emotionally open, and more receptive to social contact and support.
As the hormone of orgasm, labour and breastfeeding, oxytocin encourages us
to "forget ourselves", either through altruism- service to others- or
through feelings of love. Oxytocin, injected into specific parts of the
brain, induces mothering behaviour in virgin animals.
The flight or flight hormones- sometimes
referred to as catacholamines (pronounced cat-e-kol-a-meens), or CAs,
because of their chemical structure- can interfere with oxytocin release
during labour and after the birth. However they do have an important role
to play in the second stage of labour, which is when birth actually
Early in second stage, when the cervix is fully open but the urge to
push is not yet strong, a woman can feel the need to rest for some time.
This is known as ‘transition’- or the ‘rest and be thankful’ time. After
this, she may quite suddenly experience the dry mouth, dilated pupils and
sudden burst of energy that are all characteristic of high levels of CAs.
This burst of CA’s gives a mother the energy to push her baby out, and
Michel Odent observes that women are usually upright during this stage,
often also having a sudden need to grasp something and bend at the knees.
Some traditional cultures have used this flight-or-fight effect to help
women having difficulty with the delivery by surprising or shouting out at
this stage. It makes sense, at this point-of-no-return, for fear or danger
to speed up the birth, so that mother and newborn baby can run for safety.
CA levels peak with the birth, then drop very quickly. High levels of
CAs in animals have been shown to help with imprinting- the process which
bonds a mother to her offspring-, so it may be assumed that CAs are part
of the euphoric "hormonal cocktail" that a mother experiences in the first
hour after an unmedicated birth. This steep drop in CA levels can make a
mother may feel cold or shaky. At this stage a very warm atmosphere is
essential, according to Michel Odent, to keep CA levels low and to allow
oxytocin to work effectively to prevent bleeding.
The other major birthing hormone, prolactin, is most
noteworthy for its effects after the birth. Prolactin levels are high
during pregnancy, but its effects are blocked by the presence of other
pregnancy hormones. With the expulsion of the placenta, prolactin’s
effects are unblocked, and it becomes the major hormone of breast milk
synthesis. Suckling by the newborn baby increases prolactin levels, and it
is believed that early and frequent suckling from the first days makes the
breast more responsive to prolactin, which in turn helps to ensure a good
long-term supply of milk.
Like the other hormones, prolactin has effects on emotion and
behaviour. Prolactin stimulates ‘aggressive/defensive’ behaviour in new
mothers- what I call the "tiger mother" effect. As well as this, prolactin
helps us to put our babies needs first in all situations by increasing
"submissiveness" and vigilance. When prolactin is combined with oxytocin,
as it is soon after birth and during breastfeeding, it encourages a
euphoric and selfless devotion to the baby that contributes to a mothers
satisfaction and her baby’s physical and emotional health.
Beta endorphin (pronounced beet-a en-door-fin)is one
of the endorphin hormones which are released by the brain in times of
stress or pain, and which are the bodies natural equivalents to opiate
drugs like morphine and pethidine.
In pregnancy beta-endorphin levels are very high, and it may even play
an important role in keeping women pregnant. During labour, beta-endorphin
helps to relieve pain, and contributes to the "on another planet" feeling
that most women have when they labour without drugs. Levels of
beta-endorphin are reduced when drugs are used for pain relief.
Very high levels of beta-endorphin can slow labour by reducing oxytocin
levels, which may help to ‘ration’ the intensity of labour according to
our ability to deal with it. Moderate levels of beta-endorphin help us to
deal with pain in labour, as well as encouraging us to follow our
instincts. As part of the hormonal cocktail after birth, beta-endorphin
plays a role in bonding between mother and baby, who is also primed with
endorphins from the birth process.
Beta-endorphin also switches on learning and memory, perhaps explaining
why we remember our labour and birth in such amazing detail. Like
oxytocin, endorphin hormones can induce a euphoria and are also released
during love-making and breastfeeding. In fact endorphins are actually
present in breast milk, which explains the natural high that babies can
get after a breast feed. Beta-endorphin helps the body to release
prolactin, underlining the elaborate interplay between these hormones of
labour, birth and breastfeeding.
So there you are, at the door, with your bag in your hand and a strong
contraction. You remember the oxytocin and endorphins, which you also
carry with you, and with your next relaxed breath, you breathe out all of
your fear and tension. You’ve packed your new nursing bra, and you know
that prolactin will come to your aid as well. As you take a last look
around the house, you catch the eye of your cat.
She’s lying down as her kittens attach to her nipples, and you are sure
that you see her wink at you.
'Sarah Buckley is the mother of four babies born at home. She is a
General Practitioner who has written many papers and articles over the
years and now lives in Brisbane. Her fourth baby was an undiagnosed
footling breech who was born in their bath at home, assisted by her father
and three older siblings.'
For Details about Sarah's brilliant new book see http://www.sarahjbuckley.com/
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