July 12, 2007

Chronic Mild Stress During Pregnancy May Increase Risk of Brain Disorders in Child

Research into maternal stress during pregnancy has revealed links to increased risk for a long list of brain disorders and diseases for the child - from lower intelligence, to higher rates of autism and ADHD, as well as higher rates of schizophrenia. (see "The Importance of Low Stress in Brain Development"). Researchers have suggested independently that since stress during pregnancy doesn't directly impact the development of every child, there must be certain genes that predispose people to brain development problems when they are exposed to stress in the womb.

Now, in a new study that further validates the importance of having all members of a family working to lower the stress experienced by a mother during pregnancy, research shows that even chronic mild stress in pregnant mothers also increases the risk of the neurological disorder called cerebral palsy.

The new research study out of France suggests that chronic mild stress in pregnant mothers can increase the risk that their offspring will develop cerebral palsy--a group of neurological disorders that is marked by physical disability.

The study, led by Pierre Gressens, MD, PhD, of Inserm in France, used a mice to test whether exposure to minimal but repeated stress throughout gestation would make the offspring more vulnerable to brain lesions similar to those observed in children with cerebral palsy.

Mice are frequently used in these types of research studies because they are good representations of what happens in humans in similar situations (99 percent of genes in mice are shared with humans) and because tests like this could never be done on humans due to ethical concerns.

"These findings are consistent with growing evidence that constant stress, even minimal, can have a major impact on the quality of life," for the child in the future, said Victoria Luine, PhD, professor of psychology at New York's Hunter College, who did not participate in the research.

In the study, the scientists adjusted the normal cycle of light and dark that the pregnant mice were accustomed to for half of the mice, subjecting them to a mild level of stress. Then the researchers exposed the brains of the developing fetuses to injury. When the brains of the young mice were examined on birth, Gressens and his team found that the offspring born from stressed mothers showed brain lesions about twice as big as those in offspring of unstressed mothers.

"Determining the impact of gestational stress on the incidence of cerebral palsy would be of paramount interest," says Gressens. "Limiting stress during human pregnancy might prove to be a cost-efficient way to reduce the human, emotional, social and economic burden of cerebral palsy."

The study was titled "Chronic Mild Stress during Gestation Worsens Neonatal Brain Lesions in Mice" and the findings are published in the July 11 issue of The Journal of Neuroscience. Inserm, l'Institut national de la santé et de la recherche médicale, is the French public biomedical research agency.

Source: This story has been adapted from a news release issued by Society for Neuroscience.

Related Reading:

Stress Harms Baby's Brain While in Womb

Pregnancy stress 'passed to baby'

How to Lower Stress, Anxiety, Worry and Depression Before Pregnancy

The Importance of Low Stress in Brain Development

The Long-term Impact of Stress During Childhood on Brain Development

Preventing Schizophrenia - Risk Reduction Approaches


I believe that a key was actually the mild chronic stress... but in any case - mothers-to-be finally have a research reason to banish a stress-inducing "in-law" from their lives. ;-)

However, since stresses are such an inevitable part of lives with husbands off to war, family dying, not having medical insurance or dental insurance, poverty, mean bosses, etc... more needs to be done to research protective measures for the fetus in spite of the genes... like, if a spouse, parent or child dies while the mother is pregnant, or having a lousy boss, or bullying co-workers,or the stress of worrying that an illegal immigrant loved one will be deported... the list is endless... maybe a shot of something (like B-12 or whatever they find) being able to counteract that stress-effect.

Of course though, we are not yet at the point of knowing who would need that intervention in pregnancy let alone what the intervention would be.... but we are getting closer.

I wonder if this effect actually is part of the same effect seen with viral infections - like getting the flu in pregnancy - that it isn't really which virus, but the fact that the mother is stressed from getting sick.

And if that is true, then perhaps even the stress-effect of allergies may be harmful on the developing fetus. Right now, doctors say no antihistamines because that can be harmful to the fetus - but what if NOT having the antihistamines is ALSO harmful to the fetus (depending on genes) because of the chronic stress of the allergies themselves.

I can see that we have a long way to go answering a lot of questions.


Posted by: Naomi at July 12, 2007 01:31 PM


I really like your points about finding an intervention that would work to be neuro-protective in the face of excess stress and cortisol in a pregnant woman's body - what a great idea.

I found an interesting "Google Answers" response to the question on what can be used to lower cortisol levels in a person - and while none of the supplements would be recommended for a pregnant woman (because they could be harmful to the baby) - it seems that researchers around the world should begin immediately to test these supplements on pregnant animals to see if there is a positive impact. Then eventually, with lots of testing, perhaps some of these could be used in pregnant women.

Google Answers on What Can Reduce High Cortisol Levels in a Person

Of course, there are many cognitive behavioral therapies that are proven in stress and anxiety reduction - so there is still a lot of things that a person can do even today, to lower their stress (and therefore Cortisol) levels.

Posted by: szadmin at July 12, 2007 01:57 PM

I am wondering if anyone can answer this as well... we talk about high levels of cortisol in pregnant mothers, but have studies been done on levels in the children (or adults) with schizophrenia/schizoaffective? I know one person with childhood-onset sz-a that has had a a lot of hormone testing had LOW cortisol, along with low thyroid, low parathyroid, and low testosterone, AND abnormailities in vitamin/mineral levels.

Just wondering what is up with that and if it is at all related to possible high cortisol levels in the mother - like perhaps genetically there is a problem with regulating these hormone levels to begin with.

Anyone know?


Posted by: Naomi at July 13, 2007 06:22 AM

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