The biology of bonding
Bonding with your baby:
Science, nature, or just random chance? Sarah Tennant
investigates the physiology of bonding, discovering the remarkable
ways our bodies work to connect us with our
offspring.
If you were offered a pill to make you a better mother to your
newborn - more attuned to his cues, more committed to
breastfeeding, happier and calmer - would you take it?
At first blush it seems like a strange,
even offensive question. It is always disconcerting when science
links our most soaring and poetic emotions to chemical
interactions, and mother love is burdened with thousands of years
of lofty prose. For those lucky enough to gaze into their newborn's
eyes and fall instantly in love, the question seems almost
indecent.
Then there are the rest of us; those who
spent two days in the birthing centre staring blankly at our baby,
wondering politely when we could give it back and resume our normal
lives. Some of us may already be taking drugs, in part to be better
wives and mothers. We may suffer from chronic depression, bipolar
disorder or severe PMS; as such, our stability depends on
acknowledging that our biochemistry affects our
relationships. We are likely to answer the question with a
hearty, "Yes, please!".
As it happens, this pill doesn't yet
exist. What does exist is a growing body of evidence that the
difference between "good" and "bad" mothers is largely
physiological, not psychological. Bonded, well-attuned mothers
don't have better morals - just better biochemistry, possibly
combined with childcare philosophies which allow their
hormones to sing. If scientists can produce neglectful or devoted
animal mothers at will by adding or withholding nutrients, it seems
worthwhile to examine the biology of bonding.
It turns out that the human body is
exquisitely designed for parenting. Sans unnecessary medical
interference and aberrant child-rearing philosophies, bonding
occurs naturally and strongly. The complex interplay of factors
which create good bonding could fill volumes, but certain star
hormones deserve a closer look.
Oxytocin
Known variously as the "love hormone", "cuddle hormone", or
"mothering hormone", oxytocin is all about social interaction.
Chances are you had some floating around your system when the baby
was conceived. You also feel its seductive charms when you share a
meal with friends, eat chocolate, or hug a loved one. Oxytocin
causes people to be more trusting, generous, and empathic and less
fearful; it also promotes recognition of faces. In general, high
doses of this hormone cause people to feel more positive about
social interactions - a handy trait for a mother whose newborn's
interactions largely consist of screaming in the middle of the
night!
In a normal labour, the body will produce
oxytocin to trigger contractions. It will produce it again when the
baby suckles after birth. This not only encourages the uterus to
shrink back to its pre-pregnancy size, but also begins to bond
mother and baby together. According to Linda Palmer in The
Chemistry of Attachment, "Under the early influence of oxytocin,
nerve junctions in certain areas of a mother's brain actually
undergo reorganisation, thereby making her maternal behaviors
'hard-wired'."
Unfortunately, birth interventions can
disrupt this hard-wiring. Synthetic oxytocin is commonly used in
induced labours, and given with epidurals to compensate for the
resulting slowed labour. Synthetic oxytocin has been shown to
reduce the levels of natural oxytocin produced by the mother. One
study noted that women with epidurals and analgesics had lower
oxytocin levels and breastfed their infants less frequently than
woman who birthed naturally. Additionally, women who cannot
breastfeed don't get a "top-up" of the hormone every time their
baby eats.
Researchers are now so aware of the
importance of oxytocin that a partial solution is being
investigated in Sydney. New mothers are being given oxytocin in the
form of a nasal spray, along with play therapy, in the hopes that
this will facilitate bonding.
Prolactin
A common experience of early
motherhood is sitting down to breastfeed with the intention of
getting up as soon as the baby's finished - and remaining in that
position for the next hour in a contented haze, after the baby
decides to follow her feed with a leisurely nap. You have prolactin
to thank for this. The hormone - which, as the name implies, is
involved in milk production - fosters bonding in a rather sneaky
way, by causing you to feel relaxed and lethargic while you nurse.
(Incidentally, this phenomenon was not discovered by medical
science. Victorian novelist and mother of six Elizabeth Gaskell
mentions it repeatedly in her 1863 novel Sylvia's
Lovers.)
Prolactin also obliquely encourages
bonding by reducing sexual desire and fertility - nature's way of
ensuring the current baby gets its fair share of cuddles before a
new one comes along. If that sounds a bit staid, fear not - high
prolactin levels stimulate the production of opioids. Yes,
parenting is literally addictive.
Opioids
Opioids reinforce advantageous behaviour for mother and baby that
might otherwise be considered too troublesome to bother with -
learning to suckle for a sleepy newborn, or cuddling the baby for a
sleep-deprived mother (or father). Because the brain gets a "fix"
every time these activities are performed, they gradually become
associated with pleasure. This is also how "loveys" and security
blankets work - by associating them with a pleasurable activity
such as feeding, the baby learns to feel pleasure in the presence
of the object. Like any addictive substance, opioids run the risk
of losing their effectiveness over time. Fortunately, oxytocin
inhibits this effect, ensuring the brain continues to get a high
from the same stimuli.
Manganese and zinc
There's a reason prenatal vitamins contain manganese and zinc:
Without them, you might eat your baby. Well, not quite - but
numerous studies have shown that animals deficient in these
elements tend to be sub-par in the parenting department. Some
forget to lick and suckle their babies, while others just wander
off. In animals, this is often associated with first-time mothers
forgetting to eat the placenta, which is full of nutrients
including zinc. Indeed, many human societies around the world
engage in placentaphagy (placenta-eating) to prevent PPD and
rebuild nutrient and iron stores. For the (slightly) less
squeamish, placentas can be dried, ground, and put into capsules
for as-needed feel-good doses. If that doesn't sound appealing,
regular zinc and manganese supplementation are also beneficial. One
study found that mothers on zinc supplementation reported feeling
less tired, more energised and less irritable. Their babies also
seemed more content, and the women tended to breastfeed for
longer.
Deciphering the body's messages
So what are these hormones and minerals trying to tell us? Firstly,
that bonding is important. These complex biofeedback systems exist
for a reason. Many rather heartbreaking studies demonstrate that
bonding is far from being an "optional extra" for privileged
middle-class babies - it is necessary for life.
Babies who do not receive near-constant
love, touch and attention suffer permanent brain changes which
shape how they respond to stress and relate to others. Elevated
cortisol levels from constant separation anxiety prevent a baby's
brain from focusing on new learning experiences, stunting her
mental development because she exists in a primitive survival
state. The science of attachment theory expanded greatly after
doctors realised too many babies were wasting away in isolation
wards - babies whose nutritional needs were being met, but who were
never picked up and cuddled. Today, "kangaroo care" is seen as an
effective therapy for premature and sick infants.
Secondly, the biology of bonding tells us
that it's not a once-or-never thing. Bonding occurs best during the
first 12 hours of life, and if the baby breastfeeds within an hour
after birth; but this doesn't mean a mother knocked out after an
emergency C-section has no chance for a close relationship with her
child.
Many of the bonding systems, such as the
opiates system, are cumulative. Mothers whose babies spent their
first weeks in the NICU can still initiate baby massage and
skin-to-skin contact; mothers who gave up on breastfeeding due to
depression can bottle-nurse instead of bottle-propping. Even
better, pregnant mothers with a previous history of poor bonding
can start supplementing zinc and manganese and planning a
low-intervention birth.
Thirdly, the evidence of our bodies shows
that the Western belief that attachment makes mothers unhappy is
deeply suspect. So many parenting tools and gadgets are designed to
separate a mother and her baby. Cots, bouncinettes, schedules, and
"cry-it-out" systems all work on the assumption that being
separated from your baby will make you both happier. Yet
traditional societies, in which mothers are wearing and touching
their babies almost twenty-four hours a day have far lower rates of
maternal depression and anxiety. The opiates, oxytocin and
prolactin produced by regular baby-snuggling may be the best way to
treat such feelings - a kind of biological "fake it till you make
it" with benefits for your baby as well as for you.
My newborn is now a noisy two-year-old,
and I'm beginning to see our early efforts at attachment parenting
pay off. I'm also finding that when we get out of sync, I can
restore harmony with my toddler with a bit of skin-to skin bonding,
nursing and snuggles. Now, if only I could source a vitamin that
enabled me to find lost toddler socks...
Sarah Tennant is a freelance writer based in
Hamilton.
Resources
- Anisfeld E, Casper V, Nozyce M, Cunningham N. "Does infant
carrying promote attachment? An experimental study of the effects
of increased physical contact on the development of attachment."
Child Development 61.5 (Oct 1990): 1617-27.
- Barker-Vile, A. "Improved Breast Feeding Retention Rates
Associated with Postnatal Maternal Oral Zinc Supplementation." 3rd
National Rural Health Conference, 1995.
Online:http://nrha.ruralhealth.org.au/conferences/docs/PAPERS/3_ALIBAR.pdf
- Naish, F and Roberts, J. The Natural Way to Better Birth
and Bonding. Doubleday, 2000.
- Mothers Early Experience of Parenting. http://meep.psy.unsw.edu.au
- Palmer, Linda F, "The Chemistry of Attachment."Attachment
Parenting International News 5.2 (2002).
As seen in OHbaby!
magazine Issue 12: 2011
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