New research from the U.S. suggests that women who suffer from stress during pregnancy may increase the risk of their child developing allergies.
Scientists at Harvard Medical School say they have found higher levels of a chemical linked to allergies in the blood of children whose of mothers are stressed.
According to the researchers the levels were high even in those who had not been exposed to recognised allergy triggers such as dust mites.
The researchers conducted a study of 387 babies, and found that babies exposed to stress before birth have an increased tendency to react to allergy triggers and it lends support to the theory that stress may influence the body's immune response.
Dr. Rosalind Wright says it is thought that asthma and allergies are controlled by a complex mix of genetic and environmental factors but it is also suspected that the impact of these factors may in some way be influenced by the environment a foetus is exposed to while still in the uterus.
In order to examine the premise that stress during pregnancy can magnify the effect of foetal exposure to substances which trigger allergies, the Harvard team measured the levels of Immunoglobulin (IgE) - a chemical linked to allergic responses - in the umbilical cord blood of the babies.
As even babies exposed to low levels of dust mites in the uterus displayed elevated levels of IgE, the researchers say that stress was amplifying their allergic response.
Dr. Wright of Brigham & Women's Hospital and Harvard Medical School, says their research adds to a growing body of evidence that links maternal stress, such as that caused by financial problems or relationship issues, to changes in children's developing immune systems, even during pregnancy.