Toxins in seafood, including mercury—which may be especially high in canned tuna—can present risks during pregnancy, including shorter cerebellums and lower IQ in babies. Many of these pollutants accumulate in the body for years, some taking decades to exit the body. It may be advisable to get tested for mercury before getting pregnant.

Exposure during pregnancy to parasites in lamb meat or phthalates in chicken may lead to future problems for baby boys and girls. One study found an association between the development of childhood allergies and higher maternal intake of meat during pregnancy.

Eating meat before pregnancy can increase risk for diabetes during pregnancy. Exposure to fumes from grilling meat may adversely affect fetus development. The levels of pesticides on GMO soy is a concern. So far, no human harm has been shown to come from genetically modified Bt corn. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Other risks during pregnancy may be introduced by the consumption of aspartame, spirulina, iodinedomoic acid in tuna, alcohol, licorice, and even avocadoschamomile tea, and flax seeds. Health food store workers may not always recommend pregnancy-safe nutrients. Iron supplements should perhaps only be taken only in the context of iron deficiency anemia. Folic acid and turmeric supplements should not be taken during pregnancy in most cases (although pregnant women should make sure to eat plenty of folate-rich foods). Items that are considered safe to consume during pregnancy include peanuts, cranberry juice, and moderate amounts of caffeine. 

A vegan diet lacking vitamin B12 is dangerous for mother and fetus. Vegan women have fewer twins than vegetarians and omnivores.

 Topic summary contributed by Johanna.