When I was pregnant with my first son I didn’t even think about food allergies. I worried about just about everything else - spinobifida, downs, and a hundred other things I read about--but not food allergies. I tried to drink milk because I “heard” it was good (no doubt from dairy industry advertising) and I ate peanut butter and jelly crackers as I did throughout my life for an evening snack or occasional lunch. Oddly I craved eggs, especially during the first trimester for each of my sons. Both of my sons remain allergic to eggs now at ages 5 and 7. Only one remains allergic to dairy--the oldest. We are okay with peanuts and tree nuts (almonds, beechnuts, brazil nuts, cashews, chestnuts, gingko, hazelnuts, hickory nuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts) because we’ve carefully avoided them.
In retrospect, had I known that my own family history showed a strong tendency towards dairy and egg allergies, and had I been more informed about food allergies in general, I would have avoided eating these foods while I was pregnant. My cousin and his father, my uncle, both had egg and dairy allergies when they were infants. My cousin even had to be hospitalized during his third month of life for lack of weight gain. My aunt told me that she had to feed him soy formula after that occasion. Now my cousin is in his late thirties and I am told by his sister that he still avoids milk but that it is not life threatening to him--only sickening.
If I were pregnant again, I’d eat what I eat now--a dairy and egg free diet. Nor do I eat peanuts or tree nuts--after seven years of not eating them, I noticed how sick they make me feel. I was shopping one day and bought a small container of mixed nuts for lunch--perhaps one half cup of peanuts, cashews, almonds mixed with cranberries and raisins. They laid in my stomach for several hours (certainly no allergic response, but a testament to how difficult they are to digest). I do eat potatoes, rice, meat, fish and lots of vegetables and fruit. I think that is a good diet for pregnancy, unless there is a history of a fish or shellfish allergy, at which point I’d avoid that as well. Normally food allergies develop for high protein foods because the body can have trouble properly digesting those foods. The big eight are: soy, wheat, egg, dairy, fish, shellfish, peanut and tree nuts.
Another thing that I would do would be to supplement myself with probiotics. Probiotics are good bacteria that can rebalance a person’s intestinal tract so that it can properly digest foods. If a person’s intestinal tract is damaged by overuse of antibiotics, then the food can go into the blood stream through little holes in the intestinal wall--a disorder known as ‘leaky gut syndrome.’ There have been some studies that show that pregnant women who supplement with probiotics have a lower incidence of having babies with food allergies, as detailed in my probiotics chapter. Even supplementing after the child is born, if the mother is breastfeeding, can help the baby avoid food allergies.
Recently, I read a book called “Hidden Food Allergies” by James Braley and Patrick Holford. It is the first time that I have seen a recommendation by a doctor along this line. The book states, “Pregnant women who suffer from allergies have been found to be more likely to have babies who develop allergies and asthma, according to a five-year study funded by the British Lung Foundation and Asthma U.K. The researchers, however, found that it is possible to minimize that risk by reducing a woman’s exposure to allergens while she is pregnant. Dr. Jill Warner…said…”Our research shows that mothers can influence whether their baby develops sensitization to allergies. Controlling the mothers’ reactions to allergens, especially during the second and third trimesters of pregnancy, may well be the treatment of the future…’”
In summary, avoiding known family allergens and common allergens (like peanuts or the other big eight listed above) while supplementing with probiotics during pregnancy and breastfeeding months can help a mother ward off allergies in her baby, some think, such as myself. It is too early to have proof from studies and there are currently many conflicting viewpoints. Personally, we were told to wait to introduce peanuts to our boys until they outgrew their allergies. Once our younger son outgrew his dairy allergy, we tried one half of a raw, organic peanut several times over a few weeks (dry roasted peanuts can cause more allergies than boiled or raw peanuts). He had no reaction. But we still have not introduced peanuts to our older son who remains allergic to dairy and is now seven. Why would we do this? Why not give his digestive system a chance to fully heal itself before introducing this potentially dangerous food. The same goes for all tree nuts in our household. Better safe than sorry. I was pleased to see Dr. Braly make this recommendation as well, "We therefore generally recommend that parents refrain from giving their children peanut butter or other peanut or nut products until after they're two years old. If there is a family history of food allergies, parents should wait until the child is three. And many doctors recommend that their pregnant patients--especially those with food allergies--keep the lid on the peanut butter jar until after the baby is born and they've finished breast-feeding...at least until six months..."
 Braley, M.D., James, Holford, Patrick, "Hidden Food Allergies," Basic Health Publications, Inc., Laguna Beach, CA, originally published by Piatkus Books, Ltd, Great Britain, London, England 2005, page 89.
 Braley, page 69.