The Dietary Reference Intakes (DRIs) for energy needs during pregnancy increase 150 kcal (627 kJ) per day during the first trimester and then rise to 350 kcal per day (1,463 kJ) during the second and third trimesters. If a woman also exercises, her energy needs will increase above those required for pregnancy (Wang & Apgar, 1998). The increase in energy needed for exercise will depend on the type, intensity, frequency, and duration of the activity. Supplementation, especially for iron and folic acid, are typically provided by the physician during pregnancy. A woman’s folic acid needs double during pregnancy, and her iron needs often increase as well, especially in the later stages of pregnancy (Araujo, 1997; Orr, 1999). Figure 4.1 provides a food pyramid that will be useful for your pregnant clients. Here are more details about nutritional issues during pregnancy:
- Folate. Folate needs increase for pregnant women to prevent neural tube defects (in which the child is born with an underdeveloped brain or no brain at all, known as anencephaly) or spina bifida (in which the spinal cord does not completely close) and to promote normal growth of the fetus and placenta. The Dietary Reference Intake (DRI), established as a Recommended Dietary Allowance (RDA), for folate is 600 mg per day. At least 400 mg of that should be derived from fortified foods or supplementation because folate from those sources is better absorbed in the body. Some rich food sources of folate are fortified cereals, lentils, spinach, asparagus, and broccoli (Mahan & Escott-Stump, 2004).
- Iron. As the maternal blood supply increases, the need for iron also increases. The RDA for iron for pregnant women is 27 mg per day (Tolerable Upper Intake Level, or UL = 45 mg per day). Iron supplementation is usually recommended and often needed to prevent iron deficiency. Many obstetric and gynecology practitioners prescribe a multivitamin supplement with iron. Iron absorption is enhanced when consumed with vitamin C. For example, a glass of orange juice taken with a multivitamin with iron will increase absorption of the iron. Coffee and tea should not be consumed with iron because the tannins in these beverages interferes with iron absorption (Mahan & Escott-Stump, 2004).
- Nausea and vomiting. As mentioned previously, one of the complications of pregnancy is nausea and vomiting. Pregnant women can consume certain foods to minimize nausea and vomiting, but the bottom line is that women should eat and drink what they can tolerate. If a woman continues to experience nausea and vomiting and is unable to consume adequate energy, she should contact her obstetrician or gynecologist. Some ways to avoid or minimize nausea and vomiting during pregnancy are to minimize smells (perhaps by having meals cooked or prepared outside the house), to consume saltines or carbonated beverages when nauseated, and to consume (sip) ginger ale. Some women have found it helpful to have a package of saltines by the bed and to eat a few crackers before getting up because nausea is often the worst in the morning. Pregnant women should continue to take their multivitamin with iron, especially if food intake is decreased.
- Contraindicated practices. The following should be avoided during pregnancy:
- Taking herbal preparations, which are not regulated by the federal government, can be dangerous because the purity of these products cannot be guaranteed. In addition, some herbs can cause miscarriages. Thus, a pregnant woman should avoid these preparations.
- Vitamin megadosing is also dangerous. Even one megadose of vitamin A could lead to birth defects. The pregnant woman should rely on her physician’s recommendations regarding vitamin supplementation.
- Dieting should be avoided. Pregnancy is not the time for a woman to lose weight. Weight gain guidelines differ based on prepregnancy body weight.
- Consuming too much caffeine is unwise because caffeine can cross the placenta. Pregnant women should seek advice from their obstetrician or gynecologist about how much caffeine they can consume.
- Pregnant women should not drink alcohol at all. Consuming it can lead to fetal alcohol syndrome (FAS). Even small doses of alcohol can prevent oxygen delivery through the umbilical cord, causing brain damage, retarded growth, facial and vision abnormalities, and low Apgar scores.
- Smoking restricts blood supply to the fetus, limiting oxygen and nutrient delivery and removal of waste, slows growth, retards physical development, and could lead to low weight at birth. Even secondhand smoke can contribute to problems.
- Hypoglycemia. Because a pregnant woman experiences nausea and vomiting, especially during the first trimester, she must not allow her blood glucose levels to decrease. Eating small, frequent meals will help prevent nausea and vomiting and will help maintain blood glucose concentrations so that the future mother does not feel lightheaded or faint. In spite of such precautions, some women contract gestational diabetes during pregnancy. See the chapter on diabetes (chapter 7) for more information on this topic.
- Eating for healthy weight gain. Weight gain during pregnancy is generally within the range of 11 to 18 kg (25 to 40 lb). The amount of weight that should be gained for a safe, healthy pregnancy is based on the prepregnancy body mass index (BMI), and recommendations made accordingly are listed in table 4.1 (Mahan & Escott-Stump, 2004). The section "Weight Gain in Pregnancy" lists how the weight gain in a typical, healthy pregnancy is distributed. A healthful meal plan would include eating approximately six times throughout the day, incorporating a variety of foods in each small meal. Pregnant women should avoid too many high-fat or high-sugar foods and should focus on obtaining adequate amounts of fruits, vegetables, whole grains, lean protein, and low-fat dairy sources. Low-fat and skim milk, cheese and yogurts, and lean meats such as chicken, turkey, and other lean meats or protein substitutes are recommended. Artificial sweeteners should be avoided during pregnancy. A pregnant woman will gain more health benefits from water, milk, and juice than she will from artificially sweetened drinks.