If you're a natural worrier who once giggled at the joke "stress is the glue that holds me together," then you know exactly what constant stress feels like—and you're probably pretty used to it. But when it comes to being pregnant, you already know you need to curb your stress levels because it can affect your baby even before they're born.
Experts are now saying that fetuses actually know precisely when their mothers are experiencing toxic stress, which is a feeling of being chronically overwhelmed, anxious or depressed.
Catherine Monk, Ph.D., who studies the relationship between maternal toxic stress and fetal behavior, told KPCC she believes that this type of stress can result in depression or anxiety (or both) in the mother and can lead to the development of certain diseases later in life for the baby.
When it comes to the difference between stress and toxic stress, the main thing to keep in mind is that while life is challenging, Dr. Monk explains, "toxic stress ... tends to be threats to our self and our self-integrity, either from domestic violence or from not knowing where our next meal is coming from, housing insecurities, past abuse that’s never been resolved, very acrimonious relationships—so that if we’re pregnant, we’re not sure where the support is going to come from for our child, really unresolvable tensions between work and demands at home."
Her work primarily involves women who reflect a range of experiences during pregnancy. While some of her study subjects are having this type of toxic stress, others are having an average experience of life's natural ups and downs. After giving these women a small stressor test, her team looked at how fetuses react in the womb while their mother experiences a stressful situation.
Her research aims to find out whether the Barker hypothesis—which says that babies can develop certain diseases starting in utero—could be correct.
"This hypothesis has been supported by epidemiological data showing that nutrition and stress in pregnancy are associated with long term health outcomes in adults," she said. "Now there have been hundreds of studies making this association that toxic stress in pregnancy can put the future child at risk for mental disorders. So we wanted to contribute to this science by identifying the effect of maternal toxic stress at the time it’s occurring, so on the fetus. [This] can really add to the science by removing the post-natal influences that are also there."
Although there seems to be an indication that mothers who experience toxic stress are possibly going to have babies with a higher likelihood of developing certain disorders later on in life, Monk is cautious to say this is a probable outcome. The truth is that there are many other factors that have an effect on how our babies turn out, including their grade school teacher, cousins, the air they breathe, whatever chemicals mom may have been exposed to, and so on. But they're finding that this really severe kind of stress is a contributing factor for brain behavior problems during childhood. The good news? It's a preventable risk factor.
While she admits that some toxic stress experiences come from socio-economic factors that can feel very challenging to solve, her lab is currently working on having an intervention and work with women before the baby is born to provide them with the tools that can support them in their caregiving.
Over four sessions, the intervention focuses on one-on-one interaction and support, as well as giving the mothers other resources for support depending on their stress sources.
"We’re giving them mindfulness so that they can slow down, use sensory skills to pause when there’s a lot of stress, to check in with their own emotions," she said, "to be able to reflect on how important support feels, from what they get with their coach, thinking about how they can get it in their lives."
For the next part of her research, Monk wants to understand how a mother's mood state gets to the fetus and affects their brain development. If she and her team can fully understand how a mother's mental state can affect the baby's biological pathways before they're born, they can continue to find ways to help women eliminate toxic stress so their babies aren't negatively affected.