A study by researchers at Mount Sinai Hospital found that the more peanut products that mothers ate during pregnancy, the more likely their babies were to test positive for peanut allergy.
The study looked at babies with a known history of milk or egg allergies, but no previous testing for peanut allergy or history of reactions to peanuts. Most of the babies had not yet tried to eat a peanut.
The babies had positive blood tests for peanut allergy. They may or may not develop symptoms of peanut allergy in the future.
Researchers cautioned that this study does not prove that pregnant women should avoid peanuts. There have been some studies that found that avoiding allergens can actually increase the risk of food allergies.
Currently, the American Academy of Pediatrics (AAP) does not recommend avoiding any food during pregnancy, even for families with a history of food or other allergies. The AAP also changed its guidelines in 2008 for introducing solids to babies at risk of food allergies. Read more about the AAP guidelines for preventing food allergies in at-risk babies.