Major allergens: While pregnant and breastfeeding

AngelaRD, LDN, CBS

No convincing evidence exists that you should avoid or limit major allergens during pregnancy or breastfeeding in order to reduce the risk of allergies in your baby. In fact, the opposite is true. Restricting your diet may adversely affect maternal and fetal nutrition because exposing the immune system to the “offending” foods can actually help the body learn to tolerate them. Complete avoidance will prevent the immune system from learning that these foods are not actually harmful. The bottom line: eat a varied diet to train your growing baby’s immune system from the start.

What to Do

Eat a wide variety of foods while you are pregnant and breastfeeding

Now is not the time to restrict certain foods (unless of course you yourself are allergic), as no correlation has been shown between moms avoiding foods and allergies in their children. Plus, you need the full range of nutrients to grow a healthy baby!


The best step you can take to reduce allergies is to breastfeed your baby exclusively for six months. The antibodies, nutrients and various health-protecting substances found in breast milk help promote the development of a balanced intestinal flora, protect against infections and boost your baby’s immune system (among many other benefits).

Get plenty of omega-3’s while you’re pregnant and breastfeeding

Focus on foods like low-mercury oily fish (salmon and sardines), algae (seaweed and kelp), pasteurized dairy from grass fed cows or fortified with DHA, and nuts and seeds (especially walnuts, chia, and flax seeds). If you’re having a hard time incorporating these foods into your diet, check with your doctor about taking a supplement. Either way, your baby’s developing immune system will reap the benefits of omega-3 and DHA during development in utero and as he continues to mature in infancy.

Take advantage of probiotics and prebiotics

Probiotics are live, non-pathogenic microorganisms that have shown to be beneficial to the gut or immune system. They are found in some fermented foods such as live-cultured yogurt or supplements. Prebiotics are indigestible fiber compounds that “feed” beneficial intestinal bacteria. Breast milk is rich in prebiotics, so your baby is getting plenty if you are breastfeeding. You can boost your own intake by eating bananas, garlic, onions, leeks, and tomatoes. Oligosaccharide prebiotics, found in some of these foods, are thought to support your immune system.

Research shows that some pre- and probiotic can be beneficial to your baby’s developing gastrointestinal and immune systems

Avoid smoking and second-hand smoke

Smoking and exposure to second-hand smoke may increase your baby’s risk for allergic diseases and food allergies. In general, it is recommended to avoid any form of tobacco exposure during pregnancy and during childhood and beyond.

Introduce your infant to solid foods at around 6 months

Introducing solid foods at approximately 6 months, when your baby’s digestive tract and immune system have had more time to mature, may help to decrease the risk of developing allergies (see Introducing solids: Signs of Readiness for a full explanation). The latest research now suggests that you can introduce known allergens to your child’s diet early to help reduce the incidence of developing allergies. This means that when your baby exhibits the signs of developmental readiness to eat solid foods at around six months (but not before), major allergens can be included alongside safe, already well-tolerated first foods, unless otherwise indicated by physician.