Pregnancy is a time filled with dos and don'ts. Do take folic acid. Don't smoke. Do get daily exercise. Don't take super-hot baths.

When it comes to your diet, you face a laundry list of advice. Until recently, that advice included a caution about potentially allergy-inducing foods. In 2000, the American Academy of Pediatrics advised allergy-prone moms to avoid peanuts and tree nuts during pregnancy to help prevent their babies from getting allergies. They extended the warning to breastfeeding, adding cow's milk, eggs, and fish to the list.

But times have changed, and so has the thinking about allergy prevention. "The incidence of food allergies, particularly peanuts, has increased since those recommendations," says Frank R. Greer, MD, professor of pediatrics at the University of Wisconsin. "The idea of avoiding peanuts was based on deduction, but it seems like that wasn't a good idea."

Published medical studies find no evidence that avoiding foods like milk and eggs during pregnancy has any effect on a by's allergy risk, and little evidence that shunning peanuts helps.

https://www.whattoexpect.com/pregnancy/ask-heidi/nut-allergies.aspx