As a mother-to-be, there are very few things you wouldn’t do for the precious life you're about to welcome. You read books about what nutrients are especially important at different stages of development, read up on baby proofing and preparing your home for your baby’s arrival, and commit to eating well and staying fit during your pregnancy. Part of eating well, especially in recent years, has been a shift towards excluding more and more foods from your prenatal diet to prevent your baby from developing potentially life-threatening food allergies.

How Common Are Food Allergies?

About 6 percent of babies and toddlers have true food allergies -- defined as an immune system reaction to a food that affects multiple organs, with symptoms that range from itching to difficulty breathing or even life-threatening anaphylactic shock. These allergies are different than food intolerance or sensitivity, which causes less serious issues, ranging from gas and bloating to diarrhea. Science shows that the figure is growing -- food allergies in children are up 18 percent from 1997 to 2007.

While the exact cause for the spike has not been determined, there are many factors thought to contribute to it, including greater awareness by doctors and parents, lower immunity because of decreased exposure to bacteria, and lower exposure to allergens early in a child's life. Infants who have a parent or sibling who has asthma, food allergies or other conditions may be at greater risk.

Ever-Changing Advice

Until recently, it was believed that pregnant women should avoid consuming allergy-causing foods during pregnancy and while breastfeeding and withhold them from a child in the early years to reduce the child’s risk of developing food allergies. Among the foods on the “Do Not Eat” list are wheat, soy, cow’s milk, fish, shellfish, peanuts, tree nuts and eggs.