Prenatal mental health and the effects of stress on the foetus and the child. Should psychiatrists look beyond mental disorders?

Howard and Khalifeh ¹ provide a thorough overview of the range of diagnosable mental disorders that can occur in the perinatal period, together with their frequency and methods for treatment. They discuss this in the context of help both for the mother and to prevent possible adverse effects on the child.

However, psychiatrists and other professionals may be able to help even if the pregnant woman does not have a mental disorder. The evidence suggests that there can be an increased risk to the future child if the mother feels stressed, or has experienced early trauma. It is important to think and help beyond diagnosis.

Several different types of prenatal stress for the mother have been shown to increase the risk of emotional, behavioral and cognitive problems for the child, and to play a causal role. Such stress in the mother includes her worry about the outcome of her pregnancy, her exposure to a raised level of daily hassles, to a natural or man‐made disaster, and to emotional cruelty or other forms of domestic abuse by her partner ² .

External stressors and the mothers' lev‐els of anxiety and depression are often even higher in low and middle income countries. In these countries, there can be additional stress due to poverty, external situations such as war, higher levels of interpersonal violence, and reasons for worry about the pregnancy outcome because of high infant or maternal mortality ³ .

If the mother is stressed during pregnancy, the child is at increased risk of symptoms of anxiety and depression, attention‐deficit/hyperactivity disorder, conduct disorder, and of being on the autistic spectrum. There can be other problems, including asthma and preterm delivery. Very severe stress in the first trimester, such as the death of an older child or exposure to an earthquake, increases the risk of later schizophrenia ⁴ . With the other outcomes, there can be effects throughout pregnancy.

With all these effects of prenatal stress, the evidence shows that there is only an increase in risk to the future child. Most children are not affected, and in those who are the degree of the impact is variable. The individual genetic vulnerabilities of the child, and the nature of the postnatal care can also influence outcome.

Early childhood maltreatment of the mother has been found to be associated with altered brain structure in the newborn, with reduced cortical grey matter. This association was independent of the mother's prenatal mood, and of other potential confounding variables ⁵ . This suggests that such early trauma may affect the mother's biology in a way that in turn alters the development of the brain of her foetus, and may indicate vulnerability to later depression and other problems for the child.

The pathways by which these various types of stress affect the woman's biology and so alter foetal neurodevelopment are not fully known. But some pathways are being uncovered ⁶ . These particularly involve the hypothalamic‐pituitary‐adrenal (HPA) axis, and the immune system ⁷ . The HPA axis and other biological systems respond to a wide range of external stressors, and their response is not associated with specific diagnoses of mental illness.

There is evidence that maternal and foetal cortisol levels are correlated especially in more anxious or depressed mothers. If the mother is anxious or depressed, this can alter the function of the placenta in a way that allows more cortisol to pass through to the foetus. Raised maternal cortisol is associated with altered brain function in the child, including higher internalizing symptoms in girls via alterations in neonatal amygdala connectivity ⁸ . Possible mediating factors for the effects of early trauma are those associated with the immune system and inflammation.

If we can intervene to help reduce stresses for pregnant women, we may be able to prevent some child neurodevelopmental problems. Psychiatrists are trained to diagnose mental disorders, and diagnosis is certainly important for treatment selection and prognosis. But in some contexts it is important to think beyond terms of specific diagnoses, and stress in pregnancy is one of them.

There have been attempts to think in a new way about mental ill health. One is the development of the Research Domain Criteria. This suggests a new framework to provide empirically based theories about psychological mechanisms that may be targeted in interventions. This approach would be ideal if we had a biological test showing which pregnant women are likely to be affected in a way linked to harming the foetus and later child. We do not yet have such a test. We know too little about which biological changes in the mother mediate the effects on the foetus.

But we may still be able to help. During pregnancy almost all women have contact with health professionals, who have an important role in helping both the woman and her future child. Health systems in different countries vary. But psychiatrists can help set the agenda. A wide range of different types of stress need to be detected and addressed. This is an issue that women themselves find important. In a recent poll, women chose “stress in pregnancy” as the topic most requiring increased attention from researchers, above others such as nutrition or infant attachment, in relation to child development ⁹ , although the authors of this study do warn about the risk of alarming pregnant women about mild to moderate stress.

Thus, it may be appropriate for health professionals caring for pregnant women to explore aspects of their mental well‐being which may be a source of stress. How is the relationship with the partner? Did they suffer from early abuse or other adverse childhood experiences? Do they have specific anxiety about the outcome of their pregnancy? Have they been exposed to any other major stresses, such as fire or flood; or major problems with money or housing? These are not questions usually explored and may not lead to a specific diagnosis. But, in taking care of pregnant women and in preventing adverse outcomes for their child, we may need to think in new ways about mental health in pregnancy.

We also may need to offer other support in addition to drugs and talking therapies. These may include help with the relationship with the partner. The father is often a major source of stress, but can also be a major support. This may involve assisting with practical problems such as housing, or facilitating the provision of a stronger or more supportive social network.

The role of psychiatrists and all those car‐ing for the emotional well‐being of wom‐en in the perinatal period, and for the fu‐ture child, is much more than helping with diagnosed psychiatric disorders.