Pregnancy and Nutrition: What to Eat, What to Avoid

Nutrition means eating a healthy, balanced diet so the body gets the nutrients it needs — carbohydrates, fats, proteins, vitamins, minerals and water — to function and grow. In pregnancy it matters more than ever. You need more of many nutrients than before, and healthy daily choices help give your baby what it needs to develop and help both of you gain a healthy amount of weight.

Nutrients you need more of

• Folic acid, a B vitamin that may help prevent neural tube defects. The need rises from 400 mcg a day before pregnancy to 600 mcg a day during pregnancy and breastfeeding, from food, vitamins or both. Since that is hard to reach through food alone, most people will need a supplement containing folic acid.
• Iron, important for the baby's growth and brain development. The volume of blood in the body rises in pregnancy, so more iron is needed for mother and baby: 27 mg a day.
• Calcium, which can lower the risk of preeclampsia, a serious condition in which blood pressure rises suddenly, and which builds the baby's bones and teeth. Pregnant adults need 1,000 mg a day; pregnant teenagers aged 14 to 18 need 1,300 mg.
• Vitamin D, which helps calcium build the baby's bones and teeth. All women, pregnant or not, should get 600 IU a day.
• Protein, from sources such as beans, peas, eggs, lean meat, seafood, and unsalted nuts and seeds.
• Fluids. The body needs even more water in pregnancy to stay hydrated and support the baby, so drink enough every day.

More is not always better. Too much of some supplements can do harm — very high levels of vitamin A, for example, can cause birth defects — so take only the vitamins and minerals your provider recommends.

Weight gain

How much to gain depends on your health and your weight before pregnancy:

Ask your provider what is healthy for you. The gain should be gradual, with most of it in the last trimester.

Calories

Calorie needs depend on your weight-gain goal, which your provider can set based on your weight before pregnancy, your age and how quickly you are gaining. As a general guide:

• First trimester: probably no extra calories.
• Second trimester: usually about 340 extra calories.
• Last trimester: around 450 extra calories a day.
• Final weeks: possibly no extra calories.

Choose nutrient-rich foods rather than "empty calories" from soft drinks, candy and desserts.

What to avoid

• Alcohol. No amount is known to be safe during pregnancy.
• Fish that may be high in mercury. Limit white (albacore) tuna to 6 ounces a week, and do not eat tilefish, shark, swordfish, marlin, orange roughy or king mackerel.
• Foods more likely to carry germs that cause foodborne illness: refrigerated smoked seafood such as whitefish, salmon and mackerel; undercooked meat, poultry, eggs and seafood; refrigerated meat spreads; store-made chicken, egg or tuna salads; unpasteurized or raw milk; unpasteurized juice or cider; unpasteurized soft cheeses such as feta, Brie, queso blanco, queso fresco and blue cheese; raw sprouts of any kind; raw cookie dough; and unwashed fruits and vegetables.
• Too much caffeine, which may harm the baby. For most people it is best to stay under 200 mg a day, but ask your provider first whether you should have any.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Pregnancy and Nutrition": https://medlineplus.gov/pregnancyandnutrition.html