Mental health disorders during pregnancy and postpartum are prevalent, with approximately one in five pregnant women experiencing some form of mental health disorder. In Spain, the prevalence is around 18%. Among these, the most frequent are depressive and/or anxious disorders. Because they are often under-diagnosed, only 15% of women with mental health disorders receive some type of treatment during pregnancy.
There is considerable scientific evidence to support that depression during pregnancy has an impact on maternal health, as it increases the likelihood that these women will adopt unhealthy lifestyle habits (smoking, drugs, poor diet, less exercise). This can affect the course of the pregnancy and increase the likelihood of complications, such as preterm births and the birth of low birth weight babies or babies at higher risk of admission to the neonatal ICU.
Stress during pregnancy is associated with an increased risk of developing certain diseases in offspring
Stress, defined as any psychological discomfort, plays a fundamental role in this process. Stress sets in motion a process of biological activation and regulation that can trigger the placenta to release certain biological factors that will act on various systems in the foetus. This is the key to understanding why stress during pregnancy may be associated with an increased risk of developing certain diseases in the offspring. However, it is currently not entirely clear whether this process is associated with psycho-behavioural disorders in future children-adolescents-adults, and confirming this remains a scientific challenge.
The worsening mental health of pregnant women in pandemics
During strict confinement in the pandemic, in a previous study we conducted at Vall d'Hebron Hospital in Barcelona, we found that pregnant women had higher rates of depressive symptoms and anxiety than those assessed before the pandemic in the general pregnant population, mainly affecting women with less social support.
There is also evidence that a higher risk of depression during pregnancy is associated with higher rates of postnatal depression, which can lead to disruption of mother-baby bonding. This may also have an impact on infant care, on the stimulation the baby receives, which is known to be critical for proper neurodevelopment.
A study detects changes in the development of brain structures in the foetuses of pregnant women who suffered more stress during the pandemic
A recent study by Yuan-Chiao Lu also shows that rates of depressive and anxiety symptoms were higher in pregnant women during the pandemic compared to a pre-pandemic cohort. This study also detects some developmental changes in foetal central nervous system structures, such as a decrease in the volume of the white matter, hippocampus and cerebellum, as well as a delay in the sulcation of the cerebral cortex, using foetal magnetic resonance imaging.
However, the association of these findings in brain structures with developmental disorders later in life remains unknown at present. This study also concludes that parental education and employment status are associated with fetal brain development.
This indicates that families with better education and socio-economic status are likely to be more aware of the importance of healthy lifestyle habits during pregnancy, which promote less stress, for proper neurodevelopment during pregnancy and the early years of their children's lives. Healthy lifestyle habits include a good diet, physical exercise, avoiding exposure to toxins (such as tobacco or alcohol), maintaining good hydration and good sleep habits.
Neurodevelopment: from the embryonic period to adolescence
The study, on the other hand, has limitations, such as not including variables such as nutrition, mental health illness in the family and genetic factors, as well as ethnicity.
Finally, it should be noted that there is ample evidence to support that neurodevelopment extends from the embryonic period through adolescence and that the developmental environment therefore contains resources that can support the maturation of brain neural circuits through a combination of care, social relationships, cognitive stimulation and motor activities. This means that the period of neurodevelopment is broad, and there are many opportunities during childhood to continue to favourably influence this process. This is called neural plasticity, which is of great importance in the early years of life.
The importance of early diagnosis of depression and/or anxiety during pregnancy and/or postpartum should be emphasised, both for correct treatment and to minimise the risks to the baby. There are population-based screening strategies for mental health disorders during pregnancy that have been shown to be useful for both objectives.