Scientists have found the first concrete evidence that a mother’s stress during pregnancy changes the brain connections of her unborn child.
Newly-developed scanning techniques allowed a team at Wayne State University to examine neural activity of 47 fetuses between 30 and 37 weeks gestation.
They showed for the first time that babies of mothers in high-stress setting were developing differently to those whose mothers did not have high levels of stress, anxiety or depression.
The findings, presented today at a conference in Boston, mark a breakthrough in neuroscience, confirming a long-held theory that no technology has been able to confirm or refute until now.
The newly-developed scanning techniques allowed a team at Wayne State University to examine neural activity of 47 fetuses, to detect notable changes in the stress response region
‘The major thrill is that we have demonstrated what has long been theorized, but not yet observed in a human, which is that the stress of a mother during her pregnancy is reflected in connectional properties of her child’s developing brain,’ said lead author Moriah Thomason, of the perinatal research department who today presents her work at the annual Cognitive Neuroscience Society meeting.
Beyond the huge implications for mental health, Thomason’s findings also suggest that the brain may not develop in the sequence that we have always assumed.
It is widely-held that first the simplest systems such as vision, balance and motor functions develop first, before the most complex systems, such as stress response.
However, Thomason’s study showed that the differences between stress-exposed babies’ brains and their peers emerge almost immediately.
And those differences are most clearly seen in the stress response center (the cerebellum), suggesting this region is one of the first to develop.
New technology was crucial to make this breakthrough, to understand prenatal influences independent of environmental factors.
Using fetal resting-state fMRI, they examined functional connectivity in 47 human fetuses scanned between the 30 and 37 weeks gestation.
Conducting in-utero brain scans are challenging, mainly because it is near-impossible to keep the baby from moving about, but the new technology provides a clearer image than ever possible, making the small movements more manageable.
All of the mothers involved in the study came from poor, urban areas fraught with stress, with many reporting high levels of depression, anxiety, and worry for themselves and their loved-ones.
Above anything, Thomason said, these mothers wanted to join the study to help others like them.
‘A lot of our moms are interested in being part of this research, not because of concerns they have in their pregnancy,’ she explained, ‘but because they appreciate the heightened vulnerability of budding human life, and this is an opportunity to help other women that may not have the same fortune in their circumstances.’
‘It has long been thought that the stress of a mother during her pregnancy may imprint on the brain of her developing child.
‘[But] despite the clear importance of this time frame, we presently possess very little understanding of how functional macroscale neural networks build during this precious time in human life, or the relevance of this to future human health and development.’
She added: ‘We must consider the developing brain in context, thinking about the role of the environment in shaping the brain. It is a topic that inspires us to promote healthy brain growth, to ask what it is that we do for children in the lifestyles, opportunities, and learning conditions we create for them.’