When women are pregnant, they should focus on eating healthy, well-balanced meals and snacks. That was a constant effort of mine but I had an additional concern. My husband has a peanut allergy and I was worried that my children would have the same. I had read that avoiding foods including peanuts and peanut products during pregnancy (and nursing) could reduce an allergy risk in susceptible children.

When I was pregnant with my first son, it was helpful to have a list of foods to avoid throughout my pregnancy (and even as I continued to breastfeed.) Here is a great list that I found on pregnancyinfo.com
Foods That Should Be Avoided During Pregnancy: (pregnancyinfo.com)
1. Raw Meat (rare meats may contain bacteria, toxoplasmosis and Salmonella, all of which are harmful to your unborn baby),
2. Deli Meats (those available at a deli counter, including hot dogs or turkey, beef and chicken preparations, should not be consumed unless you re-heat them until steaming. These preparations may be contaminated with a substance called Listeria. These bacteria can harm your baby severely, and may even cause miscarriage or result in a stillborn delivery. )
3. Imported Soft Cheeses: imported unpasteurized cheeses including blue cheese, feta, Brie or camembert should be avoided. These may also contain Listeria. However, soft cheeses that are made with pasteurized milk are safe to eat. It is important to check out the label. If you are not sure whether or not a product is pasteurized, you should generally avoid it.
4. Raw eggs or undercooked eggs (have the potential to contain Salmonella.)
5. Fish: While eating fish can be beneficial during your pregnancy, there are certain types of fish that you should avoid. These include shark, swordfish, king mackerel, excess tuna and tile fish, as all of these contain high levels of mercury, which can affect your unborn child’s nervous system. Canned tuna should also be avoided due to high levels of mercury contamination. Generally it is safe to eat 12 ounces of other fish including salmon and tilapia, which are full of nutritious benefits.
6. Caffeine: While a small amount of caffeine (1 small cup a day) may provide a much needed lift for pregnant moms, in general caffeine should be avoided during pregnancy. High amounts of caffeine consumption have been linked with birth defects and increased risks of miscarriage.
7. Alcohol: Alcohol is harmful to your baby’s development. Alcohol will cross the placenta and affect your baby, so every time you drink when you are pregnant your baby does to.

Based on my husband’s allergy, I avoided eating peanut products when I was pregnant. (There were a few rare exceptions.) Did that make a difference? According to Parents.com, “Women are often advised to avoid certain foods, such as peanuts, when they're pregnant or breastfeeding. There's only one hitch: "We don't really have studies that say that's definitely going to make a difference," Dr. Sicherer says. In fact, the American Academy of Pediatrics recently updated its nutrition recommendations, saying there is no convincing evidence that women who avoid peanuts or other foods during pregnancy or breastfeeding lower their child's risk of allergies.” Sure I missed out on some strong peanut butter cravings but I was willing to do anything that might improve the chances that my kids would not have a diet restriction. I would make the same decision again, with or without the evidence.

If you are concerned about a particular allergy, I found this useful information on parents.com.
“The one thing allergy specialists do seem to agree on is that breastfeeding has a protective effect. A review of 18 studies in the Journal of the American Academy of Dermatology found that allergy-prone children who were exclusively breastfed for three months were less likely to develop eczema (a rash that's often considered the first sign that a child is allergy prone) compared with those who were fed formula. The American Academy of Pediatrics generally recommends exclusive breastfeeding for all babies for the first six months.” (Parents.com)

Best of luck to all you pregnant women and as always, consult with your doctor for more information on healthy eating during pregnancy.