A case for why we should be should be taking a population-based approach to help alleviate stress in pregnant women – especially those of lower socioeconomic status

Intergenerational disadvantage is a major problem in New Zealand. It is mainly driven by poverty, marring lives generation after generation with the effects of educational, health and economic deprivation. Sobering indicators of how intergenerational disadvantage is entrenched in our society are how child poverty rates doubled in the early 1990s and the fact we have failed to make any significant dent since then. Despite intense efforts to confront this issue, the recent government report on Child Poverty Indicators is disappointing.

While it is well understood that intergenerational disadvantage is driven mostly by environmental factors, recent scientific developments have shown looking after the mental well-being of expectant mothers is a new way to understand the issue and intervene. Detailed studies have shown mental well-being during pregnancy, both positive and negative, affects how the baby’s brain develops through chemical signals between mother and baby. The outcome of poor maternal well-being, especially in pregnancy, is a child with potentially impaired executive function.

Executive function involves a set of neurocognitive processes that help us learn and work towards a goal. It involves flexible thinking, regulating attention and the ability to stop impulsive behaviours. Importantly, it also protects against stress by promoting psychological resilience.

These are clearly core skills that enable us to function well both as an individual and productive member of society. Therefore, impaired executive function tends to bring lifelong consequences such as school failure, mental health problems emerging in adolescence, poorer relationships, inability to hold down a job, and even involvement with the justice and welfare systems.

So stress, depression or anxiety during pregnancy may affect the child’s executive function, with all the downstream adverse outcomes in later life. However, particularly worrying is latest research that shows impaired executive function can also be seen in children whose mothers experienced only mild-to-moderate symptoms. These mothers were technically not clinically depressed, as their symptoms were not severe enough to reach the threshold of clinical diagnosis.

Studies in Australia and Singapore show 30 percent of pregnant women fall into the category of having mild or moderate levels of depression. Taken together with the women experiencing more severe symptoms, the total number of affected pregnancies could be very high.

While pregnancy itself may be stressful for many women, stress can be further compounded by low socioeconomic status. This suggests Māori and Pacific women may be disproportionately affected. Conversely, having a positive mood during pregnancy can have positive impacts on the baby’s brain development.

The pathways for optimal executive function develop early in life and are mostly complete by age six. At the same time, brain development is less easily reversible as a child gets older. That is why we need to focus on the early life period to ensure the child’s executive function develops optimally and they have a good start to life. Given the link between prenatal stress and child brain development, this strongly suggests the focus should be on as early as the prenatal stage.

The impact of maternal mental health on the lifelong success of the next generation may have implications for how the cycle of intergenerational disadvantage operates. Children born to mothers who are stressed and have suboptimal mental health are at risk of impaired executive function and lower psychological resilience. If these children become pregnant when they progress to adulthood, then their impaired emotional resilience may manifest as greater stress in pregnancy. In turn, their child’s neurodevelopment is also likely to be adversely affected, potentially to a greater extent. In this way, a self-reinforcing loop with compounding effects is created, and over time intergenerational disadvantage leads to greater adversity and worse community outcomes.

An especially worrying issue is how the mental well-being of New Zealand youth has declined rapidly over the past decade. Depression before pregnancy is a risk factor for depression during pregnancy; therefore, the trends in worsening youth mental health suggest new generations of women at greater risk of poor mood during pregnancy, with consequent risk to their babies’ brain development.

This may explain why rates of intergenerational disadvantage are worsening: the problem does not just have an economic/environmental basis, but a biological one as well.

There are almost certainly no silver bullets to an issue as entrenched as intergenerational disadvantage. However, if there is a biological component to intergenerational disadvantage, then part of our efforts to confront the problem must include preventive interventions that target women’s mental well-being from before pregnancy through to after birth.

Specifically, all pregnant women should be formally screened for mood, and those who fall within the mild-to-moderate range of depressive symptoms should be given appropriate support. Reports from people working at the grassroots level, including midwives, indicate these women face difficulties accessing support services because they are considered lower priority. Yet, the latest evidence demonstrates this thinking is erroneous.

Our wider approach to maternal healthcare needs a complete rethink. We need to extend beyond individual-based approaches and use population-based approaches to help alleviate stress in women who may get pregnant or are pregnant, especially those of lower socioeconomic status. Measures such as financial support, social and educational support, and community/whānau support could all be part of the toolkit.

Support backing up these measures is strong, ranging from Nobel laureate in Economics, University of Chicago Professor James Heckman to data from the Dunedin Multidisciplinary Study led by Richie Poulton. Both have shown that if we invest in disadvantaged children, not only do the children benefit, but also the return to society is enormous. We therefore suggest that a focus on maternal mental well-being, beyond its critical value to the woman herself, may help break the cycle of intergenerational disadvantage in New Zealand.

Dr Felicia Low is a Research Fellow at Koi Tū: The Centre for Informed Futures, University of Auckland.

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