Source: Lancet  |  Posted 10 years ago

Maternal environmental risk factors for atopy, diet, birth order and smoking influence the development of the foetal immune system.

This finding provides new insight into the aetiology of atopic disease, Scottish researchers say. Investigators from the University Medical School in Aberdeen, Scotland suggest the finding also raises the prospect of preventive, public health interventions for pregnant women.

They developed a prospective study to determine whether risk factors for asthma and atopic disease exert antenatal effects. They included four risk factors: family history of atopic disease, maternal smoking, birth order and maternal dietary intake of antioxidant vitamins.

Researchers measured T helper cell proliferative responses of cord blood mononuclear cells (CBMC) from 223 neonates born to a cohort of 2,000 pregnant women. They report the magnitude of CBMC-proliferative responses to allergens increased significantly in association with family history of atopic disease and maternal smoking. Responses to allergens decreased significantly with increasing birth order and high maternal dietary intake of vitamin E.

The investigators came to two conclusions. First, the association between birth order and atopy "may therefore be a consequence of antenatal influences rather than of the protective effects of childhood infections."

Second, the association between maternal vitamin E intake and CBMC responsiveness "indicates diet during pregnancy may influence the foetal immune system in such a way as to modulate the risk of childhood atopy."