A healthy diet is essential for a healthy pregnancy because we really are what we eat. Foods consumed by mothers-to-be become building blocks for babies’ new cells, tissues and organs. Eating well during pregnancy, breastfeeding and beyond can help optimize health and prevent complications for both mother and child.
During pregnancy, women usually gain between two and four pounds in the first trimester, then three to four pounds per week during the second and third trimesters. This translates to a total of twenty-five to thirty-five pounds by the end of the pregnancy (or thirty-five to forty-five pounds if expecting twins). If women are underweight when they become pregnant, they should gain more during pregnancy, up to forty pounds. Overweight women may gain less, as little as fifteen pounds.
Maintaining a healthy weight is essential for a healthy pregnancy. Mothers who do not gain enough weight put babies at risk for low birth weight, while mothers who gain too much increase the risk for complications such as preterm delivery, gestational diabetes, and preeclampsia (a condition involving high blood pressure, protein in the urine, swelling and reduced blood flow to the placenta).
Depending on pre-pregnancy weight, women generally need one hundred to three hundred extra calories per day during the second and third trimesters of pregnancy. The best way to meet these increased requirements is by eating smaller, more frequent meals. This pattern of eating also sustains energy levels throughout the day, helps prevent heartburn and balances blood sugar levels.
The best diet for pregnant women is also the best diet for almost everybody: a wide variety of vegetables, fruits, legumes, whole grains, healthy fats like olive oil, raw nuts and seeds, and wild cold-water fish. An adequate intake of high-fiber plant foods can be critical to maintaining healthy bowel function and preventing constipation and hemorrhoids during pregnancy. Consuming at least thirty-five grams of fiber each day from a variety of whole foods is a good goal.
Meat and animal products, if eaten, should come from animals raised on pasture and never exposed to pesticides, antibiotics or hormones. Foods should be organic whenever possible, as pesticides have been linked to complications of pregnancy, including birth defects, miscarriage and preterm birth, as well as some cancers and immune disorders.
Limitations and Eliminations
During pregnancy, what women eat is just as important as what they do not eat. Pregnant women (and everyone else) should eliminate from their diet processed foods, deep-fried foods, and foods that contain sugar, white flour, artificial sweeteners or flavors, ripening agents, antibiotics, hormones, pesticides and genetically modified organisms.
Pregnant women should also limit their intake of caffeine. Those who can’t eliminate it completely should consume less than 200 milligrams (mg) per day. Coffee (7 to 8 ounces) and espresso (1 to 2 ounces) can contain between 60 and 175 mg of caffeine. Green tea is a better choice because it contains less caffeine (usually less than 50 mg per cup), acts as a potent source of healthy antioxidants and offers many other health-supportive benefits.
During pregnancy, women should avoid eating uncooked and under-cooked meats, poultry, seafood, eggs, smoked seafood, unpasteurized dairy products and processed meats like hot dogs, sliced deli meat and pate. These foods carry an increased risk of infection with Escherichia coli, salmonella, toxoplasma and/or listeria bacteria that can cause miscarriage or stillbirth. If they are eaten steaming hot, these foods can be consumed safely, but some foods, like processed meat products, are best eliminated from the diet completely because they are not healthful choices at any temperature.
Omega-3 fatty acid docosahexaenoic acid (DHA) is an important nutrient during pregnancy and it is only found in fish and seafood. Vital for brain development, memory, language comprehension, attention span, vision and motor skills, DHA must come from the diet because the human body cannot make it.
Unfortunately, studies have shown that some species of fish and seafood are contaminated with mercury, lead, cadmium, polychlorinated biphenyls (PCBs), dioxins, antibiotics and/or pesticides. These contaminants can be dangerous for anyone but pregnant women have special reason for concern because many of these toxic compounds can cause problems in reproductive, endocrine and neurological systems, all of which are essential for pregnancy. Exposure to mercury in utero can be especially damaging to fetuses, impairing brain and nervous system development. It has also been linked to problems with memory, cognitive thinking, learning, language, and visual and fine motor skills.
Two important rules apply when it comes to selecting seafood during pregnancy. First, seek out species high in DHA. Look for small, oily fish that live in cold water like salmon, halibut, herring, sardines and anchovies. Second, avoid large fish that eat other fish, such as tuna, swordfish, tilefish, marlin, king mackerel and shark. These predators accumulate higher concentrations of toxic compounds than smaller fish that live lower on the food chain. Also avoid freshwater fish like lake trout, walleye and whitefish because they are more likely than saltwater fish to be contaminated with industrial pollutants like mercury and PCBs. Because good and bad choices can vary by geographical area, find the best options in your region on the Monterey Bay Aquarium's Seafood Watch website .
Women who eat few or no animal products are at risk for deficiencies of certain nutrients, primarily iron, vitamin B12, vitamin D and protein. A good supplement can ensure adequate intake of iron and vitamins, but protein comes from the diet and consuming enough must be a daily priority.
Pregnant women need at least sixty grams of protein each day. Because plant sources are not as concentrated as animal sources, vegetarian and vegan women need to eat several servings of protein-rich foods throughout the day to meet this requirement. Good choices include beans, lentils, peas, tofu, tempeh, seitan (wheat gluten), nuts and seeds. Meatless options also include kefir, yogurt and eggs.
During pregnancy, all women require more of certain nutrients, including calcium, iron, vitamins A, C, B6, B12, folate and DHA. Although a diet rich in these nutrients is essential, a multiple vitamin-mineral supplement can offer extra insurance that pregnant women are meeting their nutritional requirements.
Women who don’t eat twelve ounces of wild cold-water fish each week should consider supplementing with fish oil to ensure sufficient DHA during pregnancy. Only buy fish oils that have been tested for purity and keep them in the fridge or freezer. Women who do not consume fish or fish oil should supplement with flax seed oil. Flax is a rich source of alpha-linoleic acid (ALA), a precursor to DHA. ALA can be converted into DHA inside the body, but the conversion process is not efficient. Nutritionally, DHA-rich fish oil is a far superior choice, but ALA-rich flax seed oil is the best vegetarian alternative.
Everyone, especially pregnant women, should talk to their doctor before taking any new medicines. This includes vitamins and fish oil, because interactions can occur and not all supplements are appropriate for all individuals.