Mothers' levels of stress during pregnancy may effect the immune system of their babies according to a study carried out by researchers at Harvard Medical School. The study of 387 mothers and their babies in Boston looked at levels of maternal stress, exposure to dust-mite allergens and levels of a substance called IgE in umbilical-cord blood. The researchers found increased levels of IgE expression - indicating immune-system problems - among infants whose mothers had experienced higher levels of stress. This link held true even when the women had been exposed to relatively low levels of dust-mite allergens during their pregnancy and regardless of the mother's race, class, education or smoking history.
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