Many studies have established that prenatal stress in the form of life and emotional stress to the mother during pregnancy can have a lasting negative impact on the behavior and biology of the offspring. The children of such mothers have an increased risk of malformations, asthma, and mental and behavioral disorders. So much so that, the National Institutes of Health (NIH) and the World Health Organization (WHO) has recommended that the role of maternal stress during pregnancy should be given high research priority.

In view of this, Clinical psychologist Marion Tegethoff and colleagues conducted a study to determine whether stress during pregnancy could be a risk factor for various child diseases in the offspring.

The study was based on data from the Danish National Birth Cohort. The information on maternal stress was gathered from a telephone interview taken around 30 weeks of gestation. And information on children’s diseases was derived from the Danish National Hospital Register. Complete information on maternal stress during and after pregnancy as well as the data on diagnoses was available for 66,203 (99 percent) of the eligible mother–child pairs that participated in all of the relevant interviews.

The results were disturbing –

• There was an increased risk of mental disorders during the first 2.5 years of life in children of mothers reporting high life stress during pregnancy compared with mothers reporting low life stress.

• Maternal life stress during pregnancy was also associated with an increased risk in the diseases of the eye, ear, respiratory system, digestive system, skin, musculoskeletal system and genitourinary system in children.

• Maternal life stress during pregnancy was again associated with an increased risk of congenital malformations in offspring.

• Maternal emotional stress during pregnancy was associated with an increased risk for the first diagnosis of infectious and parasitic diseases.

• There was a decreased risk for the first diagnosis of endocrine and metabolic disorders, diseases of the eye, and the circulatory system up to 3 years of age in children whose mothers were emotionally stressed during pregnancy. However, the researchers felt that ‘it was too early to conclude whether common forms of maternal emotional stress during pregnancy have the potential to protect certain organ systems against disease’.

The researchers did not exclude the possibility of associations between the stress-related changes in lifestyle or health related factors during pregnancy and child diseases.

There is also a direct relationship between nutrition during pregnancy and a range of offspring diseases.

Further, alcohol consumption during pregnancy has been associated with birth defects and impaired offspring development and behavior.

The analysis of the data revealed that elevated stress levels across pregnancy altered the production of pro-inflammatory cytokines (proteins that serve as messengers between cells of the immune system) in the offspring; the dysregulation of cytokine production could cause certain mental disorders, infectious diseases and diseases of the various body systems.

One limitation of the study was that the researchers did not have data on the timing of the maternal stress exposure during pregnancy, which may play a role in the relationship between stress and long-term health.

The researchers concluded that ‘the observed associations between maternal stress during pregnancy and offspring health may have implications for public health and health care policy:

-   First, further investment in the reduction of life stress during pregnancy may be an important opportunity to improve child health.

-   Second, our findings encourage consideration of preventive strategies for infants of mothers who were highly stressed during pregnancy’.