A new study conducted by researchers at the University of Cape Town (UCT) and published in Brain Research Bulletin indicates that these foundational brain networks may be influenced before birth by maternal psychological distress.
University of Cape Town Study Links Prenatal Distress to Toddler Brain Networks
The research examined 111 children between two and three years of age. These children belong to the Drakenstein Child Health Study, which is a long-running South African birth cohort study led by Professor Heather Zar and the late Professor Dan Stein. The comparison involved children whose mothers experienced psychological distress during pregnancy—a broad term that covers heightened symptoms of conditions such as depression and anxiety—and children whose mothers did not report such distress.
Weaker Connections Between Emotional Detectors and Control Centers
The research team, led by Professor Kirsty Donald and Dr Marlie Miles, discovered that children born to mothers who experienced psychological distress exhibited significantly weaker communication between specific brain regions. Specifically, the analysis revealed reduced connectivity between the amygdala, which functions as the brain’s emotional significance and signal detector, and two separate regions of the prefrontal cortex responsible for helping control emotional responses and behavior.
Researchers noted that these distinct differences between the groups remained constant even after accounting for various other factors. These controlled variables included the children’s age and sex, prenatal exposure to alcohol and tobacco, and the maternal HIV status.
To capture these detailed images of brain function without disturbing the participants, the research team scanned the children while they slept naturally, successfully avoiding the use of sedation.
Broader Implications and Global Context
The study provides critical context by shifting focus away from high-income countries, where the majority of previous studies examining prenatal psychological distress on children’s brains have historically been conducted. Women residing in low- and middle-income countries, including South Africa, frequently encounter additional external challenges such as poverty, food insecurity, violence, and limited access to mental health care, all of which heighten their risk of experiencing psychological distress during pregnancy.
This study demonstrates that despite very different cultural, geographical and economic environments, the similarities in findings demonstrating the intergenerational effects of stress shown in research conducted across the world, support the hypothesis of common biological mechanisms that shape how the developing brain responds to stress before birth,
Prof Donald explained.
Furthermore, the investigation monitored behavioral outcomes in the children. While children who experienced exposure to maternal distress displayed a slight tendency toward increased aggressive behavior by three and a half years of age, researchers confirmed that this specific finding was not strong enough to establish a direct link. Conversely, stronger communication observed between other distinct brain networks was connected to fewer attention problems, indicating that these specific networks play an important role in overall emotional and behavioral development.
Calls for Routine Integration Into Pregnancy Care
Study authors emphasized that the growing body of evidence highlights the necessity of incorporating mental health support directly into routine healthcare services for pregnant women.
We believe improving mental health services for pregnant women could benefit both mothers and their children by supporting healthier brain development before birth,
noted Dr Marlie Miles. While urging caution when interpreting early behavioral findings, Dr Miles and her colleagues reiterated that supporting maternal mental health serves as an essential investment in the long-term well-being of children.
