Diet and Nutrition During Pregnancy

Good prenatal nutrition promotes the development of a healthy newborn. You will need to adjust your diet during pregnancy to meet increased nutrient needs and become aware of and avoid eating foods that could be harmful to your newborn during gestation. The following guidelines highlight important aspects of diet and nutrition during pregnancy.

Increased Nutrient Needs

Calories: An average of 300 extra calories per day is needed during your second and third trimesters (500 to600 extra calories for twins). Although the saying “eating for two” implies that you need lots of extra food, it really means eating just a little more and choosing foods with high nutritional value.

Protein: Protein provides the building blocks for the development of human cells and tissue. Adequate protein intake is essential throughout pregnancy. Approximately 60 grams of protein per day is recommended. This is 10 to 15 grams above pre-pregnancy needs. You can easily get an extra 10 to 15 grams of protein from the following:
• 2 cups of milk (16 gms)
• 2 ounces of chicken, fish, or meat (14 gms)
• 2 eggs (12 gms)
• 3 tablespoons of nut butter (peanut/almond/cashew/soy) (12 gms)
• 2 ounces of nuts (10 gms)
• 2 ounces of cheese (14 gms)
• 4 ounces of firm tofu (13 gms)
• 1 cup of yogurt (10 gms)

Vitamins and Minerals
Virtually all vitamins and minerals need to be increased during pregnancy with special attention to foods rich in folic acid, iron, and calcium. Ideally, increased vitamins and minerals can be obtained through a nutritious diet, but a prenatal vitamin supplement is usually recommended to ensure adequate intake.

Suggested Daily Food Intake
• Fruit: 2 to 4 servings (include at least one citrus fruit or juice) This will provide vitamin C and fiber. Yellow/orange fruit also provides vitamin A.
• Vegetables: 3 to 5 servings (include at least two dark leafy, yellow, or orange vegetables). These will provide fiber, vitamin C, and vitamin A. Dark leafy greens also provide iron.
• Grains: 6 to 11 servings (at least half should be whole grain, choose enriched cereals, rice, breads). These will provide fiber and B vitamins. Enriched products also provide iron and folic acid.
• Protein foods: 2 to 3 servings (chicken/fish/meat, eggs, nuts, tofu, beans, cheese, yogurt) These foods provide protein and iron (in animal flesh and eggs).
• Milk products: 3 to 4 servings (1 serving = 8 oz milk/yogurt or 1 oz cheese) Provides calcium and protein.
• Fats: Use fat in moderation, but include sources of omega-3 fatty acids (salmon, walnuts, flax, and canola oil).

Food Safety

Foodborne illnesses can be especially harmful during pregnancy. To reduce your risk:
• Do not eat any raw seafood such as clams, oysters, sushi, and cviche. This includes refigerated, uncooked smoked seafood. Canned or shelf-stable smoked seafood may be eaten.
• Avoid eating raw or undercooked meats, fish, poultry, and eggs.
• Avoid potential sources of listeria. Listeria is a bacterium that can cause severe illnesses. Pregnant women are much more susceptible to infection than others. The most common source of the bacteria is food made of unpasteurized milk and milk products. Pasteurization kills the listeria organism. All cheeses made in the US are fairly safe, as regulations require that they must be made from pasteurized milk. However, imported soft and semi-soft cheeses made from unpasteurized milk may contain listeria. Consequently, the Food and Drug Administration (FDA) advises that pregnant women avoid the following cheeses if they are made fromunpasteurized milk: Brie, Camembert, Feta, Goat, Limburger, Montrachet, Neufchatel, Queso Fresco, Asiago, Belle Paese, Blue, Brick, Gorgonzola, Havarti, Muenster, Port-Salut, Roquefort.
• Due to possible listeria contamination, the FDA also recommends heating hot dogs and deli meats until steaming hot and avoiding refrigerated meat spreads or meat pates (canned or shelf-stable are safe).

Safe Seafood Consumption for Pregnant & Lactating Women:
Protecting your child from exposure to mercury and other toxins

Seafood can be an important part of a balanced diet for pregnant and lactating women. It is an excellent source of low fat, high quality protein and other nutrients including omega-3 fatty acids. Omega-3 fatty acids are especially important during pregnancy and lactation because they are necessary for infant brain and nervous system development. They are not produced by the body and must be obtained from one’s diet. While certain seafood is a good source of these fats, some may also contain high levels of mercury, PCBs (polychlorinated biphenyl compounds), and other potential toxins. Therefore, caution must be used in choosing the type and amount of seafood that you eat.

Mercury is a known neurotoxin. High levels of mercury may be especially harmful to the developing nervous system of a fetus, infant and young child. If a pregnant woman has a high level of mercury stored in her body tissues, this can expose the developing fetus to mercury. Also, during lactation, mercury in the mother's body can pass into her breast milk. And, young children may be exposed to mercury from eating certain types of fish.

Mercury occurs naturally in the environment. However, unnaturally large amounts of mercury are present in the environment as a result of industrial pollution, especially from coal burning power plants. Mercury falls from the air into water and accumulates in streams, rivers and oceans. Nearly all fish contain trace amounts of mercury, but larger fish accumulate high levels of mercury in their tissues and pose the greatest potential risk to people who eat them regularly. Mercury is stored in our tissues as well, so intake over time is cumulative.

The importance of minimizing exposure to mercury for pregnant and lactating women is internationally recognized. The Food and Drug Administration (FDA), Environmental Protection Association (EPA), and the National Academy of Sciences are among the groups that have issued guidelines.

What about farm-raised salmon? 
A recently published study found increased levels of certain contaminants in some farm-raised salmon. Salmon is an excellent source of omega-3 fatty acids and you can still include it in your diet while pregnant and nursing. To minimize possible exposure to contaminants:
• Choose wild salmon whenever possible, fresh, frozen, or canned (almost all canned is wild)
• Choose farm-raised salmon from North and South America (Washington State, Chile). These salmon had the lowest levels of contaminants; those from Northern Europe had the highest levels.

What about canned tuna?
Tuna may contain significant amounts of mercury. However, light tuna has just half the mercury of white tuna. The FDA states that up to 12 ounces a week of tuna should be safe to eat. However, many public health agencies, including the National Academy of Sciences, believe that standards should be much more conservative to minimize mercury exposure.

Recommended limits on tuna consumption for pregnant or nursing women and young children:
• Women weighing 120 pounds should not eat more than 8 ounces of light tuna or 4 ounces of white tuna per week.
• Children weighing 60 pounds should not eat more than 4 ounces of light tuna or 2 ounces of white tuna per week.

If I'm eating less fish, how can I get omega-3 fats?
There are a number of dietary sources of omega-3 fats or their precursors that you can easily add to your diet. These include:
• Walnuts: add them chopped to cereal, baked goods, or snack on them out of hand.
• Flax seeds: sprinkle on cereal; add to batters and baked goods. You will get the most benefit if you grind the seeds shortly before consuming (use a coffee grinder)
• Canola oil: use as you would any other oil
• Wheat germ: add to cereal and baked goods
• Eggs high in omega-3: These eggs are from hens fed diets that are high in vitamin E and flax.

Where can I get more information on mercury and seafood?

Environmental Protection Agency
www.epa.gov/ost/fish

Massachusetts Department of Public Health
www.state.ma.us/dph or 617-624-5757