Background on what we know about Maternal Prenatal Stress
As many readers might already know, exposing pregnant women to stress at constantly high levels can be detrimental to foetal development, placing the newborn at an extreme disadvantage emotionally and intellectually. There is much evidence to suggest that a newborn's cognitive abilities are affected for quite some time after birth.
How does this happen you might ask? The verdict is still out with researchers on the exact mechanism around transmission of stress hormones from mother to foetus. We do know that when a mother is exposed to a stressful event, her brain triggers a reaction which releases a stress hormone known as cortisol. Although cortisol and other hormones allow the mother to cope with the impending stressful event, it's been shown that the hormones can actually pass to the foetus via the mother's placenta.
It is these high levels of cortisol that can then affect the cognitive abilities of newborns.
The good news is that the adverse effects on impaired cognitive abilities in newborns is entirely reversible "so long as children received consistent, loving attention from at least one caregiver. "
So can all maternal prenatal stress be reversed? We thought - until now.
Breakthrough study on type of maternal prenatal stress and its consequences
A landmark longitudinal study has been published recently that has been a game-changing study for the field of epigenetics. For the very first time, a team of researchers and scientists from McGill University in Canada have been able to demonstrate that a single stressful event prenatally can permanently alter the DNA of their newborn.
These researchers studied children born during the infamous ice storm in Quebec, Canada and along the US/Canadian border in 1998 that caused several weeks, up to 45 days in some cases, of power outages among other stressful difficulties. The study called Project Ice Storm had researchers recruit women who had been pregnant during the disaster and assessed their degrees of hardship and distress during this period.
Study: Project Ice Storm
Several years later, the researchers found that DNA within the immune system's T-cells of 36 children showed distinctive patterns in DNA methylation. The researchers concluded that maternal hardship, predicted the degree of methylation of DNA in the T-cells.
For the first time, this study showed that it is the objective stress exposure (such as days without electricity) and not the degree of emotional distress in pregnant women that causes long lasting changes in the DNA of their babies.
What do findings mean
The total picture of what these consequences mean for the children is not clear as of yet, but scientists believe changes in the genes related to specifically immunity and sugar metabolism detected in them as babies can put them at a greater risk in developing asthma, diabetes or obesity later in life, proving that these children had responded to their mother's prenatal stress.