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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 four newborn kittens in
the linen cupboard.
Why
does birth seem so easy to our animal friends
when it is so difficult for us? One obvious
difference is the altered shape of the pelvis
and birth outlet that is caused by our upright
stance; 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 behaviour.
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.
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 fight-or-flight
hormones adrenaline and noradrenaline (epinephrine
and norepinephrine) 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 levels of prolactin,
which is sometimes referred to as the nesting
hormone. At this stage, as you may have
observed with your cat, interference which
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 fight-or-flight 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 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, and some women
can be as sensitive as a cat to the presence
of an observer. Giving birth away from our
natural environment can cause the sorts
of difficulties for humans that captive
animals experience when giving birth in
a zoo.
Michel
Odent cautions that even hunger, which also
causes the body to release fight-or-flight
hormones, can stop labour from progressing.
He advises women to eat- if they are hungry-
in the earliest stages of labour; many hospitals,
though, have a policy that prevents labouring
women from eating once they are admitted.
Oxytocin
is the hormone that causes the uterus to
contract during labour. Levels of oxytocin
gradually increase throughout labour, and
are highest around the time of birth, when
it contributes 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 as the baby is born,
does not occur when an epidural is in place.
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
so does not contribute to the post-birth
“high”, and in fact can lead
to desensitisation to the mothers own oxytocin
production. Nipple stimulation is sometimes
used to stimulate contractions 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 post-partum
haemorrhage.
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.
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.
The
fight or flight hormones- also called catecholamines
(pronounced cat-e-kol-a-meens), or CAs-
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 occurs.
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 sometimes known as 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, when unmedicated, women usually want
to be upright at this time. Some traditional
cultures have used this fight-or-flight
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 a mother can gather up her newborn
baby and run for safety.
CA
levels drop quickly after the birth, which
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 is the major hormone
of breast milk synthesis. Suckling by the
newborn baby increases prolactin levels;
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 helps
us to put our babies needs first in all
situations by increasing submissiveness,
anxiety and vigilance.
When
prolactin is combined with oxytocin, as
it is soon after birth and during breastfeeding,
it encourages a relaxed and selfless devotion
to the baby that contributes to a mother’s
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 is a natural equivalent to
painkilling drugs like pethidine.
During
labour, beta-endorphin helps to relieve
pain, and contributes to the “on another
planet” feeling that women experience
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 euphoria and
are also released during lovemaking 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 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 notice your cat.
She’s
lying down as her kittens attach to her
nipples, and as you catch her eye, she winks
at you.
Sarah
J Buckley is a family physician/GP, an internationally-acclaimed
writer on pregnancy, birth, and parenting
and mother of four children, all born at
home 1990-2000. Sarah's new book Gentle
Birth, Gentle Mothering: The wisdom and
science of gentle choices in pregnancy,
birth, and parenting, which is a
collection of her
best articles, is now available at www.sarahjbuckley.com
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