Stress levels in pregnant women have been linked to the increased chances of the child developing asthma or other allergies
Stress levels in pregnant women have been linked to the increased chances of the child developing asthma or other allergies.
Researchers at Harvard Medical School studied 387 babies and found higher levels of a chemical linked to allergy in the blood of children of stressed mothers.
In order to discover whether stress during pregnancy can magnify the effect of foetal exposure to substances which can trigger allergy the researchers measured levels of Immunoglobulin (IgE) - a chemical linked to allergic responses - in the umbilical cord blood.
Previous animal studies have suggested that the combination of stress and allergen exposure during pregnancy may magnify the effects on the immune system, but this is the first human study to examine this directly.
In the new human study the researchers found increased levels of IgE expression in cord blood among infants whose mothers experienced higher level stress even when exposed to relatively low levels of dust mites during pregnancy.
Commenting on the results, Dr Rosalind Wright of Harvard Medical School said: "This research adds to a growing body of evidence that links maternal stress such as that precipitated by financial problems or relationship issues, to changes in childrenï¿½s developing immune systems, even during pregnancy.
"This further supports the notion that stress can be thought of as a social pollutant that, when 'breathed' into the body, may influence the body's immune response similar to the effects of physical pollutants like allergens, thus adding to their effects."