Harmful stress: Study finds mum's stress in pregnancy affects her baby for life
In today's hectic world, stress is widespread.
And while stress, especially chronic stress, can have serious health implication for everyone, it can cause even more harm when it happens to pregnant women – and even end up putting their infant at risk for cognitive problems later in life.
According to a large-scale study at the University of Denver, researchers Elysia Poggi Davis and Pilyoung Kim set out to understand how the early environment affects a child's life course, and found that stress hormones (and medications that mimic them) may have long-lasting effects on infants. And it all begins in the womb.
Experts are working to understand how the early environment affects a child's life course — but the environment that researchers Elysia Poggi Davis and Pilyoung Kim are interested in isn't just the home or the neighbourhood, but also the womb.
"I think we're becoming aware that we have to start thinking of these things during pregnancy, not waiting until after the baby is born," Davis recently told Live Science.
In another study, published in 2011 in The Journal of Child Psychology and Psychiatry, 116 women were monitored throughout their pregnancies, testing their levels of cortisol, a hormone released in response to stress. Testing took place every month or so in the second and third trimesters. After the babies were born, the researchers measured each infant's cortisol after routine blood drawn from the foot, and also recorded each baby's response to the blood draw.
Researchers found that the greater the exposure to mum's cortisol in the womb, the larger was the infants' own cortisol spike in response to a blood draw in the first day of life. These cortisol-exposed infants also calmed down less readily after the blood draw ended.
Even more worrying is that other research projects have found the first direct human evidence that fetuses exposed to elevated levels of the stress hormone cortisol, could have trouble paying attention or solving problems as they grow up.
Forging a strong bond between mother and baby can counteract the effect of stress in utero
However, it seems like all is not lost, even if you did go through a particularly stressful period when you were pregnant, mama.
Because according to a study by Thomas O’Connor, a professor of psychiatry and psychology at the University of Rochester Medical Center in New York, the negative link between stress in the womb and the long-term effects of this on a child's attention span and problem solving disappears almost entirely if the mother forges a secure connection with her baby.
A while back, O'Connor and his colleagues recruited 125 pregnant women, and took samples of their amniotic fluid so that stress hormones levels could be measured.
When their children reached 17 months of age, researchers tested cognitive abilities with puzzles, pretend play, and baby memory challenges.
They also watched the baby and mother interact, and using something known as the Ainsworth "Strange Situation" test, which judges childrearing quality, categorized these mum-baby pairs as either showing secure or insecure attachment to each other.
What became evident was that for the insecure mom-baby pairs, the mums who had higher prenatal stress hormone levels were more likely to have kids with shorter attention spans and weaker language and problem-solving skills. But for kids who had secure relationships with their mums, any negative link between high prenatal cortisol exposure and kids' cognitive development was eliminated.
"Pregnancy is an emotional experience for many women, and there is already so much for mothers to be careful of and concerned about," O'Connor said of his research. "It's a relief to learn that, by being good parents, they might 'buffer'’ their babies against potential setbacks."