By the time a child celebrates their third birthday, the foundations of emotional regulation are already being laid deep within the brain – and a new University of Cape Town (UCT) study published in Brain Research Bulletin suggests that those foundations may even be influenced before birth.
Researchers have found that children whose mothers experienced psychological distress during pregnancy – a broad term encompassing heightened symptoms of various psychological conditions like depression and anxiety – showed measurable differences in the communication between brain regions responsible for processing and regulating emotions. The findings add to other compelling evidence done in high income countries that a mother’s mental well-being during pregnancy may leave a biological imprint on her child’s developing brain.
The study examined 111 children aged between two and three years from the Drakenstein Child Health Study, a South African birth cohort study. Using resting-state functional magnetic resonance imaging, the researchers compared brain communication patterns in children whose mothers experienced prenatal psychological distress with those whose mothers did not.
The team, led by Professor Kirsty Donald and Dr Marlie Miles, found significantly weaker communication between the amygdala – the brain’s emotional significance detector – and two regions of the prefrontal cortex that help control emotional responses and behaviour when comparing children born to mothers who had experienced psychological distress, compared to children of mothers who did not report experiencing distress.
The differences between these groups remained even after researchers accounted for factors including children’s age and sex, prenatal alcohol and tobacco exposure, and maternal HIV status.
“Our findings suggest that the effects of psychological distress during pregnancy can be detected in the developing brain during the first years of life,” says Prof Donald, deputy director of the UCT Neuroscience Institute. “They reinforce the idea that pregnancy is a critical period for brain development and that supporting maternal mental health is an important investment in children’s long-term wellbeing.”
The findings are especially important because most previous studies examining the effects of prenatal psychological distress on children’s brains have been conducted in high-income countries.
Women living in low- and middle-income countries often face additional pressures – including poverty, food insecurity, intimate partner and/or community violence and limited access to mental healthcare – that increase their risk of psychological distress during pregnancy. Yet evidence from these settings has remained scarce.
“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,” says Prof Donald.
The researchers focused on the amygdala because it plays a central role in recognising threats and prioritising emotional responses. During early childhood, the amygdala develops earlier than the prefrontal cortex, which gradually learns to regulate emotional reactions throughout childhood and adolescence. If communication between these regions is disrupted during this critical developmental window, it may influence emotional regulation later in life.
The study also explored whether early brain connectivity predicted later behaviour.
While children exposed to maternal distress showed a tendency towards more aggressive behaviour by three-and-a-half years of age, the difference was not statistically significant. However, stronger communication between the hippocampus and prefrontal cortex was associated with fewer attention problems, suggesting that these brain circuits may play an important role in children’s behavioural development.
The researchers emphasised that these behavioural findings are exploratory and require confirmation in larger studies.
“Although these behavioural findings should be interpreted cautiously, they point to possible pathways linking early brain development with later emotional and behavioural outcomes,” says Dr Miles, who is now based at Stellenbosch University. “Understanding these pathways may eventually help identify children who could benefit from earlier support.”
Collecting high-quality brain scans from children is difficult. Rather than using sedation, the research team scanned children as they slept naturally, capturing detailed images of brain function without interrupting normal sleep.
The study also benefits from being embedded within the Drakenstein Child Health Study, a long-running birth cohort, led by Professor Heather Zar and the late Professor Dan Stein. This enables researchers to follow families from pregnancy into early childhood using prospectively collected data rather than relying on parents’ memories years later.
The researchers acknowledge several limitations.
The number of children exposed to maternal psychological distress was relatively small, limiting the ability to detect sex-specific differences. Behavioural assessments were also based on caregiver reports because the children were too young to complete independent evaluations.
Even so, the findings add to growing evidence that maternal mental health should be considered a central part of prenatal care rather than an optional extra.
The researchers argue that altered communication between emotional brain networks may represent one biological pathway through which psychological vulnerability is passed from one generation to the next.
“Improving mental health support during pregnancy has the potential to benefit two generations at once,” says Dr Miles. “By identifying early changes in the developing brain, this research strengthens the case for integrating more mental health screening into routine antenatal care, particularly in resource-constrained settings, where women often face multiple, compounding sources of stress.
“It’s part of a much bigger picture for maternal and child mental health in South Africa, and I hope it contributes to that in a meaningful way,” Dr Miles adds.