The science of foetal origins shows how pre-natal experiences shape our future, reports Annie Murphy Paul
Consider this simple but startling proposition: the events and experiences we encounter before birth can influence us – our health and well-being, our susceptibility to disease, even our intelligence and temperament – for the rest of our lives.
I first came across this notion as a science reporter looking for interesting research to write about. Digging deeper, I found a rapidly expanding field known as foetal origins: the study of how intrauterine conditions shape the individual later in life. Then something else happened: I got pregnant.
Suddenly, what had been an intriguing concept took on a much more immediate importance. What could the new science of foetal origins tell me about what to eat, what to drink, how to manage my emotions and protect myself from environmental hazards?
Over the next nine months, I embarked on an exploration of this burgeoning discipline, applying its findings to my own pregnancy. Along the way, I came to discover that much of what we think we know about the pregnant woman and her foetus is wrong.
For example: Stress during pregnancy is always bad for the developing child. Actually, new research shows that moderate levels of stress may actually tone the foetus’s nervous system, accelerating its development. The two-week-old infants of women who experience relatively more stress during pregnancy show faster neural conduction – evidence of a more mature brain. And women who report modest anxiety and daily stress during pregnancy have children with better motor and mental development scores at the age of two.
Also incorrect is the common notion that pregnant women should avoid exercise. In fact, when a pregnant woman exercises, her foetus gets a beneficial workout, too. Foetal origins research shows that the foetuses of pregnant women who are physically active have heart rates that are slower and more variable, both signs of cardiovascular health. The babies of exercisers have lower birth weights and may even become more intelligent adults because of their bigger brains.
Many pregnant women avoid seafood, spooked by all the warnings about mercury. But eating lots of fish high in omega-3 fatty acids and low in mercury during pregnancy produces smarter kids. Children whose mothers ate at least 12 ounces of seafood a week had higher verbal IQ, better social and communication skills and superior motor skills, according to a study published in the leading medical journal The Lancet. The answer is to eat plenty of fish but to choose low-mercury varieties, such as sardines, tilapia and salmon.
One of my favourite discoveries concerned the edict that pregnant women shouldn’t eat sweets. There’s a big exception to this rule: chocolate. New studies show that pregnant women who eat chocolate every day during pregnancy have babies who show less fear and smile and laugh more often at six months of age.
Another study finds that women who eat five or more servings of chocolate each week during their third trimester have a 40 per cent lower risk of developing the dangerous high blood pressure condition known as pre-eclampsia.
My exploration of foetal origins yielded many such practical tips. But it also led me to a new perspective on pregnancy itself. Many of us believe that there’s such a thing as an ideal or perfect pregnancy that women should strive for. But research reveals that pregnancy is not a generically ideal experience to which one must aspire (and, inevitably, fall short of), but instead a highly personal and particular shaping of the foetus for the specific world into which it will be welcomed. The mix of influences it encounters in the womb are as individual and idiosyncratic as the pregnant woman herself – and that’s the way nature intended it.
The science of foetal origins tells us that our relentless focus on what can go wrong during pregnancy is misguided. We need to focus on all the things that can go right. As researchers are now discovering, it’s conditions in the womb that make a lot of things also go right in later life. The pre-natal period, it turns out, is where many of the springs of health, strength and well-being are found, leading scientists to a new and much more positive perspective on pregnancy.
It’s leading them as well to a new recognition of the profound importance of gestation in shaping the individual. Pregnancy is not just a nine-month wait for the big event of birth but a crucial period unto itself – “the staging ground for well-being and disease in later life,” as one researcher puts it.
Obstetrics was once a sleepy medical specialty, and research on pregnancy a scientific backwater. Now the nine months of gestation are the focus of intense interest and excitement, the subject of an exploding number of journal articles, books and conferences.
And, if scientists’ ideas about pregnancy are changing, so too are their ideas about the foetus. The foetus is most definitely not an inert being – a blob of tissue, as it’s often portrayed – and the pregnant woman is not its passive incubator. Rather, foetal research is revealing that the foetus is an active and dynamic creature, responding and even adapting to its surroundings as it readies itself for life in the particular world it will soon enter.
Meanwhile, scientists are learning that the pregnant woman is a powerful and often positive influence on her child even before it’s born. Pregnant women carry their foetuses with them into the world; in effect, foetuses are out on the traffic-clogged street, present at the smoke-filled party, recipients of the drinks women sip and the drugs they swallow.
Foetuses are also vulnerable to traumatic stress felt by the pregnant woman. In fact, research shows that pre-natal exposure to natural disasters and other life-or-death situations can have a lasting effect on offspring. Studies have shown earlier births among pregnant women who experienced an earthquake in California; delayed development among children whose pregnant mothers suffered through an ice storm in Canada; and early signs of post-traumatic stress syndrome in babies whose pregnant mothers experienced the 9/11 terrorist attacks. Such research is prompting renewed attention to the care of pregnant women in emergencies.
More private tragedies can also have an effect on the foetus. Research shows that as many as 10 per cent of pregnant women suffer from clinical depression, which can increase the risk of premature delivery or low birthweight. In addition, the intrauterine environment provided by a depressed or anxious woman may predispose her child to the same mood disorders. That means that therapy provided to pregnant women may also be “therapy” for the foetus.
All this adds up to a vision of pre-natal influences that’s very different from the frivolous notion of playing Mozart to a pregnant belly and the like. In reality, the nine-month-long process of shaping and moulding that goes on in the womb is far more visceral and consequential than that: it is a crucial process of preparation for the specific world the baby will enter.
What a foetus is absorbing in utero is not Mozart’s Magic Flute but the answers to questions much more critical to its survival: will it be born into a world of abundance or scarcity? Will it be safe and protected, or will it face constant dangers and threats? Will it live a long, fruitful life, or a short, harried one?
The pregnant woman’s diet and stress level, in particular, provide important clues to prevailing conditions, a finger lifted to the wind. The resulting tuning and tweaking of the foetus’s brain and other organs are part of what give humans their enormous flexibility, their ability to thrive in wildly varied environments.
The science of foetal origins, then, is nothing less than a new chapter in the long-running nature/nurture debate. We once thought that the two things that shape our individual qualities are the genes we inherit at conception and the environment we experience as a child. Foetal origins explodes this simple distinction.
To the influence of our early environment, it adds the powerful effects of our very first environment: the womb. And to the influence of genes, it contributes the effects of “epigenetic modification”, the fine-tuning of gene expression which, we’re now learning, occurs most consequentially in utero.
Pregnancy, long the subject of folk wisdom and old wives’ tales, is becoming something new: a scientific frontier.
source: telegraph
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