The study, published in the Journal of the American Medical Association, is the first to demonstrate that a mother who eats nuts during pregnancy may help build up a baby's tolerance to them after birth, its lead author, Dr. Michael Young, told CNN.
The effect seemed to be strongest in women who ate the most peanuts or tree nuts -- five or more servings per week, according to the study, which controlled for factors such as family history of nut allergies and other dietary practices.
Peanut and tree nut allergies tend to overlap, according to the researchers.
Earlier studies indicated that nut consumption during pregnancy either didn't have any effect or actually raised the risk of allergies in children.
However, the authors of the latest study say those studies were based on less reliable data and conflict with more recent research suggesting that early exposure to nuts can reduce the risk of developing allergies to them.
There is currently no formally recognized medical guidance for nut consumption during pregnancy or infancy.
Download our Food Allergy Action Plan.
Image: Pregnant woman eating nuts, via Shutterstock