For years, parents have been told that the first few years of a child’s life are crucial for brain development.
Now, new research from the University of Cape Town is adding another important piece to the picture: some foundations of emotional development may already be taking shape before a baby is born.
A UCT study of 111 South African children found measurable differences in the way brain regions involved in processing and regulating emotions communicated with one another among children whose mothers experienced psychological distress during pregnancy.
The research, published in Brain Research Bulletin, looked at children aged between two and three years who were part of the long-running Drakenstein Child Health Study, a South African birth cohort that has followed families from pregnancy into childhood.
The finding does not mean that a mother’s anxiety or depression determines her child’s future mental health. Nor does it mean pregnant women should blame themselves for experiencing stress.
What it does suggest is that pregnancy may be an important window for supporting maternal mental health with potential benefits extending beyond the mother herself.
“Our findings suggest that the effects of psychological distress during pregnancy can be detected in the developing brain during the first years of life,” said Professor Kirsty 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.”
What the researchers found?
The researchers used resting-state functional MRI scans to examine how different parts of the children’s brains communicated while they were naturally asleep.
They focused particularly on the amygdala, a brain region involved in detecting emotional significance and threats, and areas of the prefrontal cortex involved in regulating emotions and behaviour.
Children whose mothers had experienced psychological distress during pregnancy showed weaker communication between the amygdala and two prefrontal cortex regions than children whose mothers had not reported such distress.
The differences remained after researchers accounted for factors including the children’s age and sex, prenatal alcohol and tobacco exposure, and maternal HIV status.
The brain develops gradually. The amygdala develops earlier, while parts of the prefrontal cortex responsible for more complex regulation continue developing throughout childhood and adolescence.
The researchers therefore wanted to understand whether differences in these early connections could provide clues about later emotional and behavioural development.
Does this mean stress during pregnancy causes mental health problems?
Not necessarily. This is an important distinction for parents.
The study found an association, not proof that maternal psychological distress directly caused the observed brain differences. Genetics, nutrition, socioeconomic circumstances, relationships, exposure to violence, physical health and a child's experiences after birth can all influence development.
The researchers also looked at behaviour later in early childhood. Children exposed to maternal distress showed a tendency towards more aggressive behaviour at around three-and-a-half years, but this difference was not statistically significant.
Another finding was more promising: stronger communication between the hippocampus and prefrontal cortex was associated with fewer attention problems.
Dr Marlie Miles, the study’s lead researcher, stressed that these behavioural findings are exploratory and need to be tested in larger studies.
Pregnancy can happen alongside financial insecurity, food insecurity, relationship difficulties, community violence and limited access to mental healthcare. UCT’s Children’s Institute similarly identifies these very same factors as important drivers of toxic stress affecting young children’s development.
The findings also build on earlier South African research. In 2023, UCT and the University of Bath reported that intimate partner violence experienced during pregnancy was associated with changes in brain structure in infants scanned at about three weeks old.
So what should parents take from this?
Probably not another reason to panic. If anything, the message is the opposite: pregnant women need support, not guilt. Mental health should be part of the conversation when we talk about antenatal care, alongside blood pressure, nutrition, physical health and scans.
That could mean asking a pregnant woman how she is actually coping, making psychological support easier to access and recognising that anxiety or depression during pregnancy deserves proper attention.
The researchers acknowledge limitations, including the relatively small number of children exposed to maternal psychological distress and the fact that behavioural assessments relied on caregiver reports.
But the study adds to a growing body of evidence that the foundations of child development are laid remarkably early. For parents, something is reassuring in that too.
What this research tells us is that supporting the person carrying the baby is also part of supporting the baby. As Miles concluded: “Improving mental health support during pregnancy has the potential to benefit two generations at once.”