The role of stress in asthma development is poorly understood, but animal studies have suggested that the mother’s stress during pregnancy can influence the immune system of her offspring.

A total of 557 families answered detailed questions about the various sources of stress in their lives, such as at home, in their local area and financially. 

Once children were born, the researchers collected umbilical cord blood, from which isolated immune cells were stimulated with allergens like dust, viruses and bacteria. The researchers then checked for the production of different cytokines, in order to assess how a child's immune system was primed to respond in different environments. Children who were born to mothers in high stress environments were compared with those born to mothers with lower stress. The women were mainly from ethnic minorities and 20 per cent were from families who lived below the poverty threshold.

Patterns of cytokines related to certain stimulants, which act as indicators of how a child's immune system is functioning at birth, differed based on the level of stress reported by the mothers.

Cytokine patterns seen in the higher stress groups may be a marker of increased asthma and allergy risk as the children grow older.

Further research is needed as the children grow up to determine whether maternal stress levels do indeed have an impact on asthma development.

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