OB Chapter 14- Book

A commonly used method of evaluating the appropriateness of weight for height is the

BMI Body Mass Index BMI = Weight ÷ Height2 in which the weight is in kilograms and height is in meters. Thus for a woman who weighed 81 kg before pregnancy and is 1.68 m tall: BMI = 81 kg ÷ (1.68 m)2 =28.7 Prepregnant BMI can be classified into the following cat- egories: less than 18.5, underweight; 18.5 to 24.9, normal; 25 to 29.9, overweight; and 30 or greater, obese For women with single fetuses, current recommendations are that women with normal BMI should gain 11.5 to 16 kg (25 to 35 lb) during pregnancy

folate/folic acid

Because of the increase in RBC produc- tion during pregnancy, as well as the nutritional requirements of the rapidly growing cells in the fetus and placenta, pregnant women should consume about 50% more folate than nonpreg- nant women, or about 0.6 mg (600 mcg) daily. In the United States, all enriched grain products (which include most white breads, flour, and pasta) must contain folic acid at a level of 1.4 mg/kg flour. This level of fortification is designed to supply approximately 0.1 mg folic acid daily in the average American diet and has significantly increased folic acid consumption in the population as a whole. All women of childbearing potential need careful counseling about including good sources of folate in their diets (see Box 14-1). Supplemental folic acid is usually prescribed to ensure that intake is adequate. Women who have borne a child with a neural tube defect are advised to consume 4 mg of folic acid daily, and a supplement is required for them to achieve this level of intake.

water soluble vitamins

Body stores of water-soluble vitamins are much smaller than those of fat-soluble vitamins, and the water-soluble vitamins, in contrast to the fat-soluble ones, are readily excreted in the urine. Therefore, good sources of these vitamins must be con- sumed frequently, and toxicity with overdose is less likely than it is in people taking fat-soluble vitamins.

health history

Chronic maternal illnesses such as diabetes mellitus, renal dis- ease, liver disease, cystic fibrosis or other malabsorptive disor- ders, seizure disorders and the use of anticonvulsant agents, hypertension, and PKU may affect a woman's nutritional status and dietary needs. In women with illnesses that have resulted in nutritional deficits or that require dietary treatment (e.g., diabetes mellitus or PKU), it is extremely important for nutri- tional care to be started and for the condition to be optimally controlled before conception. The registered dietitian can pro- vide in-depth counseling for the woman who requires medical nutrition therapy during pregnancy and lactation.

cultural influences

Consideration of a woman's cultural food preferences enhances communication, providing a greater opportunity for compli- ance with the agreed-on pattern of intake. Women in most cul- tures are encouraged to eat a diet typical for them. The nurse needs to be aware of what constitutes a typical diet for different cultural or ethnic groups; however, within one cultural group, several variations may occur. Thus careful exploration of indi- vidual preferences is needed. Although ethnic and cultural food beliefs may seem at first glance to conflict with the dietary instruction provided by physicians, nurses, and dietitians, it is often possible for the empathic health care provider to iden- tify cultural beliefs that are congruent with the modern under- standing of pregnancy and fetal development. Many cultural food practices have some merit, or the culture would not have survived. Food cravings during pregnancy are considered nor- mal by many cultures, but the kinds of cravings often are cul- turally specific. In most cultures women crave acceptable foods, such as chicken, fish, and greens among African-Americans. Cultural influences on food intake usually lessen as the woman and her family become more integrated into the dominant culture.

potassium

Diets including adequate intakes of potassium are associated with reduced risk of hypertension. Potassium has been identified as one of the nutrients most likely to be lacking in the diets of women of childbearing age (IOM, 2006). A diet including 8 to 10 servings of unprocessed fruits and vegetables daily, along with moderate amounts of low-fat meats and dairy products, has been effective in reducing sodium intake while providing adequate amounts of potassium.

magnesium

Diets of women in the childbearing years are likely to be low in magnesium, and as many as half of preg- nant and lactating women may have inadequate intakes (IOM, 2006). Adolescents and low-income women are especially at risk. Dairy products, nuts, whole grains, and green leafy vegetables are good sources of magnesium.

medical nutrition therapy

During pregnancy and lactation, the food plan for women receiving special medical nutrition therapy may have to be modified. The registered dietitian can instruct these women about their diets and assist them in meal planning. However, the nurse should understand the basic principles of the diet and be able to reinforce the teaching. The nurse should be especially aware of the dietary modi- fications necessary for women with diabetes mellitus (gesta- tional or preexisting) because this disease is relatively common and because fetal morbidity and mortality occur more often in pregnancies complicated by hyperglycemia or hypoglycemia. Every effort should be made to maintain blood glucose levels in the normal range throughout pregnancy. The food plan of the woman with diabetes usually includes four to six meals and snacks daily, with the daily carbohydrate intake distributed fairly evenly among the meals and snacks. The complex car- bohydrates—␣fibers and starches—␣should be well represented in the diet. To maintain strict control of the blood glucose level, the pregnant woman with diabetes usually must monitor her own blood glucose daily (American Diabetes Association, 2006). The nurse must therefore teach the woman how to monitor her own blood glucose level, unless she has already been doing this before pregnancy.

case management

During pregnancy nutrition plays a key role in achieving an optimal outcome for the mother and her unborn baby. The motivation to learn about nutrition is usually greater during pregnancy because parents strive to "do what's right for the baby." Optimal nutrition cannot eliminate all the problems that may arise during pregnancy, but it does establish a good foun- dation for supporting the needs of the mother and her unborn baby

vitamin A

Adequate intake of vitamin A is needed so that sufficient amounts of the vitamin can be stored in the fetus; however, a well-chosen diet including adequate amounts of deep yel- low and deep green vegetables and fruits such as leafy greens, broccoli, carrots, cantaloupe, and apricots provides sufficient amounts of carotenes that can be converted in the body to vita- min A. Congenital malformations have occurred in infants of mothers who took excessive amounts of preformed vitamin A (from supplements) during pregnancy, and thus supplements are not recommended routinely for pregnant women. Vitamin A analogs (e.g., isotretinoin [Accutane]), which are prescribed for the treatment of cystic acne, when used dur- ing early pregnancy have been associated with an increased incidence of congenital defects, as well as an increased risk of miscarriage. Topical agents such as tretinoin (Retin-A) do not appear to enter the circulation in substantial amounts, but their safety in pregnancy has not been confirmed.

postpartum

An important goal of postpartum nutrition is for the woman to lose the weight gained during pregnancy. Retention of this weight can contribute to overweight/obesity and the development of later health problems including meta- bolic syndrome, cardiovascular disease, and diabetes. The need for a varied diet consisting of a representation of foods from all the food groups continues throughout lacta- tion. The lactating woman should be advised to consume at least 1800 kcal daily, and she should receive counseling if her diet appears to be inadequate in any nutrients. Special atten- tion should be given to her zinc, vitamin B6, and folic acid intake because the recommendations for these remain higher than those for nonpregnant women (see Table 14-1). Sufficient calcium is needed to allow for both milk formation and main- tenance of maternal bone mass. It may be difficult for lactating women to consume enough of these nutrients without careful diet planning. Obese women and normal-weight women who gain more than the recommended amount of weight during pregnancy are less likely to breastfeed than normal-weight women with appro- priate weight gain (Viswanathan et al., 2008). Obese women who do choose to breastfeed have a statistically shorter period of lactation than normal-weight women (Viswanathan et al.). The woman who does not breastfeed can lose weight gradually if she consumes a balanced diet that provides slightly less than her daily energy expenditure, although overweight and obese women with excessive weight gain during pregnancy have an increased likelihood of failing to return to their prepregnancy weights (Siega-Riz, Viswanathan, Moos, Deierlein, Mumford, Knach, et al., 2009). A reasonable weight loss goal for nonlactat- ingwomenis0.5to0.9kgperweek;alossof1kgpermonthis recommended for most lactating women. Those at risk for obe- sity and overweight need follow-up to ensure that they know how to make wise food choices, primarily from fruits, vegeta- bles, whole grains, lean meats, and low-fat dairy products. An hour of moderately vigorous physical activity (walking, jogging, swimming, cycling, aerobic dance, etc.) most days of the week will improve the ability of the woman to lose weight gradually and maintain the weight loss.

Hazards of restricting adequate weight gain

An obsession with thinness and dieting pervades the North American culture. Figure-conscious women may find it diffi- cult to make the transition from guarding against weight gain before pregnancy to valuing weight gain during pregnancy. In counseling these women the nurse can emphasize the positive effects of good nutrition as well as the adverse effects of mater- nal malnutrition (manifested by poor weight gain) on infant growth and development. This counseling includes informa- tion on the components of weight gain during pregnancy (Table 14-2) and the amount of this weight that will be lost after the birth. Because lactation can help to reduce maternal energy stores gradually, this also provides an opportunity to promote breastfeeding. In the United States 20% of women who give birth are obese (Paul, 2008). Pregnancy is not a time for a weight reduction diet. Even overweight or obese pregnant women need to gain at least enough weight to equal the weight of the products of con- ception (fetus, placenta, and amniotic fluid). If they limit their energy intake to prevent weight gain, they also may excessively limit their intake of important nutrients. Moreover, dietary restriction results in the catabolism of fat stores, which in turn augments the production of ketones. The long-term effects of mild ketonemia during pregnancy are not known, but ketonu- ria is associated with the occurrence of preterm labor. It should be stressed to obese women, and all pregnant women for that matter, that the quality of the weight gain is important, with emphasis placed on the consumption of nutrient-dense foods and the avoidance of empty-calorie foods.

physical examination

Anthropometric measurements provide short- and long- term information on a woman's nutritional status and are thus essential to the assessment. At a minimum, the woman's height and weight must be determined at the time of her first prenatal visit, and her weight should be measured at every subsequent visit (see earlier discussion of BMI). A careful physical examination can reveal objective signs of malnutrition (Table 14-5). It is important to note, however, that some of these signs are nonspecific, and the physiologic changes of pregnancy may complicate the interpretation of physical findings. For example, lower-extremity edema often occurs when caloric and protein deficiencies are present, but it also may be a normal finding in the third trimester. The inter- pretation of physical findings is made easier by a thorough health history and by laboratory testing, if indicated.

diet history

Assessment is based on a diet history (a description of the woman's usual food and beverage intake and factors affecting her nutritional status, such as medications being taken and the adequacy of income to allow her to purchase the necessary foods) obtained from an interview and review of the woman's health records, physical examination, and laboratory results. Ideally a nutritional assessment is performed before conception so that any recommended changes in diet, lifestyle, and weight can be accomplished before the woman becomes pregnant.

sodium

During pregnancy the need for sodium increases slightly, primarily because the body water is expanding (e.g., the expanding blood volume). Sodium is essential for maintaining body water balance. In the past, dietary sodium was routinely restricted in an effort to control the peripheral edema that com- monly occurs during pregnancy. It is now recognized, how- ever, that moderate peripheral edema is normal in pregnancy, occurring as a response to the fluid-retaining effects of elevated levels of estrogen. Sodium is not routinely restricted in preg- nancy, and restriction has not proved effective in reducing the rates of preeclampsia. Severe sodium restriction also may make it difficult for pregnant women to achieve an adequate diet. Grain, milk, and meat products, which are good sources of the nutrients needed during pregnancy, are significant sources of sodium. Additionally, sodium restriction may stress the adrenal glands and kidneys as they attempt to retain adequate sodium. In general, sodium restriction is necessary only if the woman has a medical condition such as renal or liver failure or hyper- tension that warrants such a restriction. On the other hand, excessive sodium intake is unwarranted because it may contribute to development of hypertension in salt-sensitive individuals. An adequate sodium intake for preg- nant and lactating women, as well as nonpregnant women in the childbearing years, is estimated to be 1.5 g/day, with a recom- mended upper limit of intake of 2.3 g/day (Otten et al., 2006). Table salt (sodium chloride) is the richest source of sodium, with approximately 2.3 g sodium contained in 1 teaspoon (6 g) of salt. Most canned foods contain added salt, unless the label states otherwise. Large amounts of sodium also are found in many processed foods, including meats (e.g., smoked or cured meats, cold cuts, and corned beef), frozen entrees and meals, baked goods, mixes for casseroles or grain products, soups, and condiments. Products low in nutritive value and exces- sively high in sodium include pretzels, potato and other chips (except salt free), pickles, catsup, prepared mustard, steak and Worcestershire sauces, some soft drinks, and bouillon. A mod- erate sodium intake can usually be achieved by salting food lightly during cooking, adding no additional salt at the table, and avoiding low-nutrient,␣high-sodium foods.

energy needs during pregnancy

Energy (kilocalories [kcal]) needs are met by carbohydrate, fat, and protein in the diet. No specific recommendations exist for the amount of carbohydrate and fat in the diet of the pregnant woman, but the intake of these nutrients should be adequate to support the recommended weight gain. Although protein can be used to supply energy, its primary role is to provide amino acids for the synthesis of new tissues. Longitudinal assessment of weight gain during preg- nancy is the best way to determine whether the kcal intake is adequate; very underweight or active women may require more than the recommended increase in kcal to sustain the desired rate of weight gain.

fluids

Essential during the exchange of nutrients and waste products across cell membranes, water is the main substance of cells, blood, lymph, amniotic fluid, and other vital body fluids. It also aids in maintaining body temperature. A good fluid intake pro- motes regular bowel function, which is sometimes a problem during pregnancy. The recommended daily intake is about 8 to 10 glasses (2.3 L) of fluid. Water, milk, and decaffeinated tea are good sources. Foods in the diet should supply an additional 700 mL or more of fluid. Dehydration may increase the risk of cramping, contractions, and preterm labor. The safety of caffeine use in pregnancy is an important issue. Some investigators (e.g., Weng, Odouli, & Li, 2008) but not others (e.g., Pollack, Louis, Sundaram, & Lum, 2010) have found that women who consume more than 200 mg of caffeine daily (equivalent to about 12 oz of coffee) may be at increased risk of miscarriage. There are also data suggesting that excess caffeine intake may contribute to IUGR. A recent review found that there is insufficient evidence to determine whether caffeine has any effect on pregnancy outcome (Jahanfar & Sharifah, 2009). Although the evidence about caffeine is far from con- clusive, the March of Dimes recommends a daily intake of no more than 200 mg of caffeine (March of Dimes, 2008). Caffeine is found not only in coffee but also in tea, some soft drinks, and chocolate (Table 14-4). Aspartame (NutraSweet, Equal), acesulfame potassium (Sunett), and sucralose (Splenda), artificial sweeteners com- monly used in low- or no-calorie beverages and low-calorie food products, have not been found to have adverse effects on the normal mother and fetus and are therefore approved by the U.S. Food and Drug Administration (FDA) for use during pregnancy. Aspartame, which contains phenylalanine, should be avoided by the pregnant woman with PKU, however (Box 14-4). Stevia (stevioside) is a sweetener sold as a dietary supple- ment; no acceptable daily intake has been established for stevia.

folate vs folic acid

Folate is the form in which this vitamin is found naturally in foods, and folic acid is the form used in fortification of grain products and otherfoods and in vitamin supplements.

client education

For many women with uncomplicated pregnancies, the nurse can serve as the primary source of nutrition education. The registered dietitian, who has specialized training in diet evaluation and plan- ning, nutritional needs during illness, and ethnic and cultural food patterns, as well as in translating nutrient needs into food patterns, frequently serves as a consultant. Pregnant women with serious nutritional problems, those with intervening illnesses such as dia- betes (either preexisting or gestational), and any others requiring in-depth nutrition counseling should be referred to the dietitian. The nurse, dietitian, physician, and nurse-midwife collaborate in helping the woman achieve nutrition-related expected outcomes. Nutritional care and teaching generally involve (1) acquainting the woman with the nutritional needs during pregnancy and the characteristics of an adequate diet, if necessary; (2) helping her to individualize her diet so that she achieves an adequate intake while conforming to her personal, cultural, financial, and health circum- stances; (3) acquainting her with strategies for coping with the nutrition-related discomforts of pregnancy; (4) helping her use nutrition supplements appropriately; and (5) consulting with and making referrals to other professionals or services as indicated. Two programs that provide nutrition services are the food stamp pro- gram and the Special Supplemental Program for Women, Infants, and Children (WIC), which provides vouchers for selected foods to pregnant and lactating women, as well as infants and children at nutritional risk

constipation

Improved bowel function generally results from increasing the intake of fiber (e.g., bran and whole-grain products, popcorn, and raw or lightly cooked vegetables) in the diet, because fiber helps to create a bulky stool that stimulates intestinal peristalsis. The recommendation for fiber intake in pregnancy is 28 g daily. An adequate fluid intake (at least 50 ml/kg/day) helps to hydrate the fiber and increase the bulk of the stool. Making a habit of participating in physical activity that uses large muscle groups (walking, swimming, water aero- bics) also helps to stimulate bowel motility.

minerals and vitamins

In general, the nutrient needs of pregnant women, with perhaps the exception of folate and iron, can be met through dietary sources. Counseling about the need for a varied diet rich in vita- mins and minerals should be a part of the early prenatal care TABLE 14-4 CAFFEINE CONTENT OF COMMON BEVERAGES AND FOODS BEVERAGE OR FOOD Coffee (8 oz [240 ml]) Espresso (1 oz [30 ml]) Tea, black, brewed (8 oz [240 ml]) Tea, ready-to-drink, with lemon (12 oz [360 ml]) Tea, green, brewed (8 oz [240 ml]) Tea, white, brewed (8 oz [240 ml]) Energy drink, Jolt, (23.5 oz [700 ml]) Energy drink, Red Bull (8.3 oz [250 ml]) Energy drink, Vault (12 oz [360 ml]) Vitamin water, Energy citrus (20 oz [600 ml]) Cola beverage, regular (12 oz [360 ml]) Hot chocolate, homemade or from mix (8 oz [240 ml]) Dark chocolate bar (1 oz [30 g]) Candy bar, milk chocolate with filling (1.5 oz [45 g]) CAFFEINE (MG) 95 64 47 7 40 35 280 80 68 50 29 5 27 6 Source: U.S. Department of Agriculture, Agricultural Research Service. (2009). USDA National Nutrient Database for Standard Reference, Release 22. Nutrient Data Labora- tory Home Page. Available at www.ars.usda.gov/ba/bhnrc/ndl. Accessed August 18, 2010; Chin, J., Merves, M., Goldberger, B., Sampson-Cone, A., & Cone, E. (2008). Caffeine content of brewed teas. Journal of Analytical Toxicology, 32 (8), 702-704; Reissig, C., Strain, E., & Griffiths, R. (2009). Caffeinated energy drinks—A growing problem. Drug and Alcohol Dependence, 99 (1-3), 1-10. of every pregnant woman and should be reinforced through- out pregnancy. However, it has been suggested that taking a micronutrient supplement (including vitamins and trace miner- als) before and during pregnancy reduces the risk of congen- ital defects, LBW, and preterm birth, as well as preeclampsia (Scholl, 2008). There is no conclusive evidence to support this suggestion, but further research is needed on maternal and fetal benefits of micronutrient supplementation (Peña-Rosas & Viteri, 2009). Supplements are especially advisable for women with known nutritional risk factors (Box 14-5). It is important that the pregnant woman understand that the use of a vitamin- mineral supplement does not lessen the need to consume a nutritious, well-balanced diet.

iron

Iron is needed to allow transfer of adequate iron to the fetus and to permit expansion of the maternal RBC mass. During preg- nancy, plasma volume increases more than RBC mass, with the difference between plasma and RBCs being greatest during the second trimester. The relative excess of plasma causes a mod- est decrease in the hemoglobin concentration and hematocrit, known as physiologic anemia of pregnancy. This is a normal adaptation during pregnancy. However, poor iron status, which can result in iron defi- ciency anemia, is relatively common among women in the childbearing years. Iron deficiency (not necessarily anemia) is estimated to affect approximately 10% of nonpregnant women in the childbearing years in the United States. Anemic women are poorly prepared to tolerate hemorrhage at the time of birth. In addition, women who have iron deficiency anemia during early pregnancy are at increased risk of preterm birth. Iron deficiency during the third trimester apparently does not carry the same risk. In the United States, anemia is most common among adolescents, African-American women, and women of lower socioeconomic status. A supplement of 30 mg of ferrous iron daily, starting by 12 weeks of gestation, helps ensure an adequate iron intake. Iron supplements may be poorly tolerated during the nausea prevalent in the first trimester, and starting the supplement after this point may improve tolerance. If maternal iron defi- ciency anemia is present (preferably diagnosed by measurement of serum ferritin, a storage form of iron), increased iron dos- ages (60 to 120 mg daily) may be required. See the Teaching for Self-Management box regarding iron supplementation. Even when a woman is taking an iron supplement, however, she also should include good food sources of iron in her daily diet

adolescent pregnancy needs

Many adolescent females have diets that provide less than the recommended intakes of key nutrients, including calcium and iron. Pregnant adolescents and their infants are at increased risk of complications during pregnancy and parturition. Growth of the pelvis is delayed in comparison to growth in stature, and this helps to explain why cephalopelvic disproportion and other mechanical problems associated with labor are common among young adolescents. Competition between the grow- ing adolescent and the fetus for nutrients also may contribute to some of the poor outcomes apparent in teen pregnancies. Recommended weight gain goals are not different from those of adult women. BMI is calculated as for adult women (IOM, 2009), rather than by using the adolescent BMI growth charts available from the Centers for Disease Control and Preven- tion (www.cdc.gov). Adolescent females that have given birth have greater percentages of total fat and visceral fat (associated with the metabolic syndrome and cardiovascular disease) than those that have never given birth (Gunderson, Striegel-Moore, Schreiber, Hudes, Biro, Daniels, et al., 2009); thus the adoles- cent mother needs careful teaching regarding nutritional intake and physical activity to control body weight in the postpartum period. Efforts to improve the nutritional health of pregnant ado- lescents focus on improving the nutrition knowledge, meal planning, and food preparation and selection skills of young women; promoting access to prenatal care; developing nutri- tion interventions and educational programs that are effective with adolescents; and striving to understand the factors that create barriers to change in the adolescent population.

physical activity during pregnancy

Moderate exercise during pregnancy yields numerous ben- efits, including improving muscle tone, potentially shortening the course of labor, and promoting a sense of well-being. Two nutritional concepts are especially important for women who choose to exercise during pregnancy. First, a liberal amount of fluid should be consumed before, during, and after exercise, because dehydration can trigger premature labor. Second, the calorie intake should be sufficient to meet the increased needs of pregnancy and the demands of exercise

nausea and vomiting

Nausea and vomiting of pregnancy (NVP) are most common during the first trimester. Most of the time NVP causes only mild to moderate problems nutritionally, although it may be a source of substantial discomfort. Anti- emetic medications, vitamin B6, ginger, or P6 acupressure may be effective in reducing the severity of symptoms, although the evidence supporting them is not strong The dose of ginger tested is a total of 1 g daily, and there is no evidence that larger doses are safe or more effective than the 1-g dose (Holst et al.). The pregnant woman may find the suggestions in Box 14-8 helpful in alleviating NVP. Hyperemesis gravidarum, or severe and persistent vomiting causing weight loss, dehydration, and electrolyte abnormalities, occurs in up to approximately 1% of pregnant women. (See Chapter 29 for further discussion.)

Nutrient needs during pregnancy

Nutrient needs are determined, at least in part, by the stage of gestation, in that the amount of fetal growth varies during the different stages of pregnancy. During the first trimester the syn- thesis of fetal tissues places relatively few demands on mater- nal nutrition; therefore, during the first trimester, when the embryo or fetus is very small, the needs are only slightly greater than those before pregnancy. In contrast, the last trimester is a period of noticeable fetal growth, when most of the fetal stores of energy and minerals are deposited. Therefore, as fetal growth progresses during the second and third trimesters, the pregnant woman's need for some nutrients increases greatly.

adequate dietary intake

Nutrition teaching can take place in a one-on-one interview or in a group setting. In either case, teaching should emphasize the importance of choosing a varied diet composed of readily avail- able foods (rather than specialized diet supplements). Good nutrition practices (and the avoidance of poor practices such as smoking and alcohol or drug use) are essential content for prenatal classes designed for women in early pregnancy. MyPyramid (www.mypyramid.gov) can be used as a guide to making daily food choices during pregnancy and lactation, just as it is during other stages of the life cycle. Additional individual- ized information and resources for professionals are avail- able from the website. The importance of consuming adequate amounts from the milk, yogurt, and cheese group must be emphasized, especially for adolescents and women younger than 25 years who are still actively adding calcium to their skeletons; adolescents need at least three to four servings from the milk group daily.

nutrient needs during lactation

Nutritional needs during lactation are similar in many ways to those during pregnancy. Needs for energy (calories), protein, calcium, iodine, zinc, the B vitamins (thiamine, riboflavin, nia- cin, pyridoxine, and vitamin B12), and vitamin C remain greater than nonpregnant needs. The recommendations for some of these (e.g., vitamin C, zinc, and protein) are slightly to mod- erately higher than those during pregnancy (see Table 14-1). This allowance covers the amount of the nutrient released in the milk, as well as needs of the mother for tissue mainte- nance. In the case of iron and folic acid, the recommendation during lactation is lower than that during pregnancy. Both of these nutrients are essential for RBC formation and thus for maintaining the increase in the blood volume that occurs dur- ing pregnancy. With the decrease in maternal blood volume to nonpregnant levels after birth, maternal iron and folic acid needs also decrease. Many lactating women have a delay in the return of menses, which also conserves blood cells and reduces iron and folic acid needs. It is especially important that the cal- cium intake be adequate; if it is not, a supplement of 600 mg of calcium per day may be needed. The recommended energy intake is an increase of 330 kcal per day for the first 6 months above the woman's nonpreg- nant daily requirement. It becomes difficult to obtain adequate nutrients for the maintenance of lactation if total intake is less than 1800 kcal. Because of the deposition of energy stores, the woman who has gained the optimal amount of weight during pregnancy is heavier after birth than at the beginning of preg- nancy. As a result of the caloric demands of lactation, however, the lactating mother usually has a gradual but steady weight loss. Most women rapidly lose several kilograms during the first month after birth, whether they breastfeed or not. After the first month the average loss during lactation is 0.5 to 1 kg per month, and a woman who is overweight may be able to lose up to 2 kg without decreasing her milk supply. Fluid intake also must be adequate to maintain milk produc- tion, but the mother's level of thirst is the best guide to the right amount. There is no need to consume more fluids than those needed to satisfy thirst. Smoking, alcohol consumption, and excessive caffeine intake should be avoided during lactation. Smoking not only may impair milk production but also exposes the infant to the risk of passive smoking. It is speculated that the infant's psy- chomotor development may be affected by maternal alcohol use, and alcohol use may impair the milk-ejection reflex (Men- nella & Pepino, 2008). Caffeine intake can lead to a reduced iron concentration in milk and consequently contribute to the development of anemia in the infant. The caffeine con- centration in milk is only approximately 1% of the mother's plasma level, but caffeine levels build up in the infant. Breast- fed infants of mothers who drink large amounts of coffee or caffeine-containing soft drinks may be unusually active and wakeful.

Obstetric and Gynecologic Effects on Nutrition

Nutritional reserves may be depleted in the multiparous woman or in the one who has had frequent pregnancies (espe- cially three pregnancies within 2 years). A history of preterm birth or birth of an LBW or small-for-gestational-age (SGA) infant may indicate inadequate dietary intake. Birth of a large- for-gestational-age (LGA) infant often indicates the existence of maternal diabetes mellitus. Previous contraceptive methods also may affect reproductive health. Increased menstrual blood loss often occurs during the first 3 to 6 months after placement of an intrauterine contraceptive device; consequently the user may have low iron stores or even iron deficiency anemia. Oral contraceptive agents conversely are associated with decreased menstrual losses and increased iron stores; however, oral contraceptives may interfere with folic acid metabolism. The woman with polycystic ovary syndrome (PCOS) is likely to be obese and insulin resistant and is prone to development of gestational diabetes

protein

Protein, with its essential constituent nitrogen, is the nutritional element basic to growth. An adequate protein intake is essential to meet increasing demands in pregnancy. These demands arise from the rapid growth of the fetus; enlargement of the uterus and its supporting structures, the mammary glands, and the placenta; increase in the maternal circulating blood volume and the subse- quent demand for increased amounts of plasma protein to main- tain colloidal osmotic pressure; and formation of amniotic fluid. Milk, meat, eggs, and cheese are complete protein foods with a high biologic value. Legumes (dried beans and peas), whole grains, and nuts also are valuable sources of protein. In addi- tion, these protein-rich foods are a source of other nutrients such as calcium, iron, and B vitamins; plant sources of protein often provide needed dietary fiber. The recommended daily food plan (Table 14-3) is a guide to the amounts of these foods that would supply the quantities of protein needed. The rec- ommendations provide for only a modest increase in protein intake (25 g daily) over the prepregnant levels in adult women. Protein intake in many people in the United States is relatively high, and thus many women may not need to increase their protein intake at all during pregnancy. Three servings of milk, yogurt, or cheese (four for adolescents) and two servings (5 to 6 oz [140 to 168 g]) of meat, poultry, or fish would supply most of the recommended protein for a pregnant woman. Additional protein would be provided by vegetables and breads, cereals, rice, or pasta. Pregnant adolescents, women from impoverished backgrounds, and women adhering to unusual diets, such as a macrobiotic (highly restricted vegetarian) diet, are those whose protein intake is most likely to be inadequate. High-protein supplements are not recommended because they have been associated with an increased incidence of preterm births. Pregnant and nursing women should be especially careful when choosing fish to select those that are low in mercury.

pyridoxine

Pyridoxine, or vitamin B6, is involved in pro- tein metabolism. Although levels of a pyridoxine-containing enzyme have been reported to be low in women with pre- eclampsia, there is no evidence that supplementation prevents or eradicates the condition. Pyridoxine has been effective in reducing the nausea and vomiting of early pregnancy in some trials

Daily Food Guide and Menu Planning

The daily food plan (see Table 14-3) can be used as a guide for educating the woman about nutritional needs during preg- nancy and lactation. This food plan is general enough to be used by women from a wide variety of cultures, including those who follow a vegetarian diet. One of the more helpful teaching strategies is to help the woman plan daily menus that follow the food plan and are affordable, are realistic in terms of prepa- ration time, and are compatible with personal preferences and cultural practices. I

weight gain during pregnancy

The desirable weight gain during pregnancy varies among women. The primary factor to consider in making a weight gain recommendation is the appropriateness of the prepreg- nancy weight for the woman's height, that is, whether the woman's weight was normal before pregnancy or whether she was underweight or overweight. Whenever possible the woman should achieve a weight in the normal range for her height before pregnancy. Maternal and fetal risks in pregnancy are increased when the mother is significantly underweight or overweight before pregnancy and when weight gain during pregnancy is either too low or too high. Severely underweight women are more likely to have preterm labor and to give birth to LBW infants. Both normal-weight and underweight women with inadequate weight gain have an increased risk of giving birth to an infant with intrauterine growth restriction (IUGR).Greater-than-expected weight gain during pregnancy may occur for many reasons, including multiple gestation, edema, gestational hypertension, and overeating. When obesity is pres- ent (either preexisting obesity or obesity that develops during pregnancy), there is an increased likelihood of macrosomia and fetopelvic disproportion; operative vaginal birth; emergency cesarean birth; postpartum hemorrhage; wound, genital tract, or urinary tract infection; birth trauma; and late fetal death. Obese women are more likely than normal-weight women to have preeclampsia and gestational diabetes.

fat soluble vitamins

The fat-soluble vitamins include vitamins A, D, E, and K. These are of special concern during pregnancy because vitamin E intake is among the nutrients most likely to be lacking in the diets of women of childbearing age, and intake of vitamins A and D is also low in the diets of some women. Fat-soluble vitamins are stored in the body tissues; in the event of prolonged overdoses, these vitamins can reach toxic levels. Because of the high potential for toxicity, pregnant women are advised to take fat-soluble vitamin supplements only as pre- scribed. Toxicity from dietary sources is very unlikely, however.

counseling about iron supplementation

The nutritional supplement most commonly needed during pregnancy is iron; however, a variety of dietary factors can affect the completeness of absorption of an iron supplement. The Teaching for Self-Management box summarizes important points regarding iron supplementation.

laboratory testing

The only nutrition-related laboratory test necessary for most pregnant women is a hematocrit or hemoglobin measurement to screen for the presence of anemia. Because of the physiologic anemia of pregnancy, the reference values for hemoglobin and hematocrit must be adjusted during pregnancy. The lower limit of the normal range for hemoglobin during pregnancy is 11 g/dl in the first and third trimesters and 10.5 g/dl in the second trimester (compared with 12 g/dl in the nonpregnant state). The lower limit of the normal range for hematocrit is 33% during the first and third trimesters and 32% in the second trimester (compared with 36% in the nonpregnant state) (Cunningham, Leveno, Bloom, Hauth, Rouse, & Spong, 2010; Pagana, & Pagana, 2009). Cutoff values for anemia are higher in women who smoke or live at high altitudes, because the decreased oxygen-carrying capacity of their RBCs causes them to produce more RBCs than other women. A woman's history or physical findings may indicate the need for additional testing, such as a complete blood cell count with a differential to identify megaloblastic or macrocytic anemia and the measurement of levels of specific vitamins or min- erals believed to be lacking in the diet

pattern of weight gain

The optimal rate of weight gain depends on the stage of preg- nancy. During the first and second trimesters, growth takes place primarily in maternal tissues, and during the third trimester, growth occurs primarily in fetal tissues. During the first trimes- ter of singleton pregnancy, the average total weight gain is only 1 to 2 kg. Thereafter the recommended weight gain increases to approximately 0.5 kg per week for an underweight woman and 0.4 kg per week for a woman of normal weight (see Fig. 14-2). The recommended weekly weight gain for overweight women during the second and third trimesters is 0.3 kg, and for obese women, 0.2 kg. The recommended energy (kcal) intake corresponds to the recommended pattern of gain (see Table 14-1). There is no increment for the first trimester; an additional 340 and 452 kcal per day over the prepregnant intake is recommended during the second and third trimesters, respectively. These recommendations are most appropriate for singleton pregnancy and may need to be adjusted in multiple gestation. The amount of food providing the needed increase in energy intake is not large. The 340 additional kcal needed during the second trimester can be provided by one additional serving from each of the following groups: milk, yogurt, or cheese (all skim milk products); fruits; vegetables; and bread, cereal, rice, or pasta. The reasons for an inadequate weight gain (less than 1 kg per month for normal-weight women or less than 0.5 kg per month for obese women during the last two trimesters) or excessive weight gain (more than 3 kg per month) should be thoroughly evaluated. Possible reasons for deviations from the expected rate of weight gain, besides inadequate or excessive dietary intake, include measurement or recording errors and differ- ences in the weight of clothing or the time of day. An exception- ally high gain is likely to result from the accumulation of fluids, and a gain of more than 3 kg in a month, especially after the twentieth week of gestation, often indicates the development of preeclampsia.

pregnancy

The pregnant woman must understand what an adequate weight gain during pregnancy means, recognize the reasons for its importance, and be able to evaluate her own gain in terms of the desirable pattern. Many women, particularly those who have worked hard to control their weight before pregnancy, may find it difficult to understand the reason the weight gain goal is so high when a newborn is so small. The nurse can explain that the maternal weight gain consists of increments in the weight of many tissues, not just the growing fetus (see Table 14-2). Dietary overindulgence, conversely, which may result in excessive fat stores that persist after giving birth, should be discouraged. Nevertheless, it is best not to focus unduly on weight gain, which can result in feelings of stress and guilt in the woman who does not achieve the preferred pattern of gain. Teaching regarding weight gain during pregnancy is summa- rized in Box 14-2.

usual maternal diet

The woman's usual food and beverage intake, the adequacy of her income and other resources to meet her nutritional needs, any dietary modifications, food allergies and intolerances, and all medications and nutrition supplements being taken, as well as pica practice and cultural dietary requirements, should be ascertained. In addition, the presence and severity of nutrition- related discomforts of pregnancy such as morning sickness, constipation, and pyrosis (heartburn) should be determined. The nurse should be alert to any evidence of eating disorders such as anorexia nervosa, bulimia, and frequent and rigorous dieting before or during pregnancy. The effect of food allergies and intolerances on nutritional status ranges from very important to almost nil. Lactose intol- erance is of special concern in pregnant and lactating women because no other food group equals milk and milk products in terms of calcium content. If a woman has lactose intolerance, the interviewer should explore her intake of other calcium sources (see Box 14-6). The assessment must include an evaluation of the woman's financial resources and her knowledge of sound dietary practices. The quality of the diet improves with increasing socioeconomic status and educational level. Poor women may not have access to adequate refrigeration and cooking facilities and may find it difficult to obtain adequate nutritious food. Food-borne ill- nesses may cause adverse effects in pregnancy, and the woman's understanding of safe food handling practices (cleansing hands, food preparation surfaces, and utensils frequently; avoiding con- tact between raw meat, fish, or poultry and other foods that will not be cooked before consumption; storing foods properly; and cooking foods to a safe temperature) should be assessed.

preeclampsia

There has been speculation that the poor intake of various nutrients might contribute to development of preeclampsia, but there is no definitive evidence. At present, a diet adequate in the recommended nutrients, along with use of a supplement that provides micronutrients both before and during pregnancy, appears to be the best means of reducing the risk of preeclampsia

fluoride

There is no evidence that prenatal fluoride supple- mentation reduces the child's likelihood of tooth decay dur- ing the preschool years. No increase in fluoride intake over the nonpregnant DRI is currently recommended during pregnancy

calcium

There is no increase in the DRI of calcium during pregnancy and lactation, in comparison to the recommendation for the nonpregnant woman (see Table 14-1). The DRI (1000 mg daily for women 19 years and older and 1300 mg for those younger than 19 years) appears to provide sufficient calcium for fetal bone and tooth development to proceed while maintain- ing maternal bone mass. Milk and yogurt are especially rich sources of calcium, providing approximately 300 mg per cup (240 m1). Nevertheless, many women do not consume these foods or do not consume adequate amounts to provide the rec- ommended intakes of calcium.

vegetarian diets

Vegetarian diets represent another cultural effect on nutri- tional status. Foods basic to almost all vegetarian diets are vegetables, fruits, legumes, nuts, seeds, and grains, but with many variations. Lacto-vegetarians include milk products. Another type of vegetarian, lacto-ovovegetarians, consumes eggs and dairy products in addition to plant products. Veg- ans, or total vegetarians consume only plant products. All of these types of vegetarian diets, if they are well planned, can be nutritionally adequate for pregnant and lactating women (Craig & Mangels, 2009). Because vitamin B12 is found only in foods of animal origin, the vegan diet may be low in vitamin B12. As a result, vegans should consume vitamin B12-fortified foods such as fortified soy milk two or three times a day or take a supplement. Vitamin B12 deficiency can result in mega- loblastic anemia, glossitis (inflamed red tongue), and neuro- logic deficits in the mother. Infants born to affected mothers are likely to have megaloblastic anemia and to exhibit neuro- developmental delays. The diet should be carefully planned to include adequate minerals. Iron and zinc may not be as well absorbed from plant foods as they are from meats, and calcium intake can be low if milk products are avoided. Plant proteins tend to be "incomplete" in that they lack one or more amino acids required for growth and the maintenance of body tissues. However, the daily consumption of a variety of different plant proteins—␣grains, dried beans and peas, nuts, and seeds—␣can provide all of the essential amino acids.

vitamin C

Vitamin C, or ascorbic acid, plays an important role in tissue formation and enhances the absorption of iron. The vitamin C needs of most women are readily met by a diet that includes at least one or two daily servings of citrus fruit or juice or another good source of the vitamin, but women who smoke need more.

vitamin D

Vitamin D plays an important role in the absorption and metabolism of calcium. The main food sources of this vitamin are enriched or fortified foods such as milk and ready-to-eat cereals. Vitamin D also is produced in the skin by the action of ultraviolet light (in sunlight). A severe deficiency may lead to neonatal hypocalcemia and tetany, as well as to hypoplasia of the tooth enamel. Women with lactose intolerance and those who do not include milk in their diet for any reason are at risk for vitamin D deficiency. Other risk factors for deficiency are dark skin, with African-American women being at high risk of deficiency; habitual use of clothing that covers most of the skin (e.g., Muslim women with extensive body covering); and living in northern latitudes where sunlight exposure is limited, espe- cially during the winter. Use of recommended amounts of sun- screen with a sun protection factor (SPF) rating of 15 or greater reduces skin vitamin D production by as much as 99%, thus bringing about a need for regular intake of fortified foods or a supplement.

vitamin E

Vitamin E is needed for protection against oxidative stress, and pregnancy is associated with increased oxidative stress. Indeed, oxidative stress has been proposed as an explanation for the etiology of preeclampsia, although supplementation with vitamin E has not been effective in reducing rates of preeclampsia. Vegetable oils and nuts are especially good sources of vitamin E, and whole grains and leafy green vegetables are moderate sources.

excessive weight gain

Weight gain is important, but pregnancy is not an excuse for uncontrolled dietary indulgence. The old saying that the preg- nant woman is "eating for two" should not be interpreted to mean that the food intake should be doubled. Instead the woman should place an emphasis on the quality of her food intake as she considers her needs and those of her fetus. Exces- sive weight gained during pregnancy may be difficult to lose after pregnancy, thus contributing to chronic overweight or obesity, an etiologic factor in a host of chronic diseases, includ- ing hypertension, diabetes mellitus, and arteriosclerotic heart disease. The woman who gains 18 kg or more is especially at risk. Food energy intake and particularly intake of fat is likely to be high among pregnant women, especially low- income women.

zinc

Zinc is a constituent of numerous enzymes involved in major metabolic pathways. Zinc deficiency is associated with malformations of the central nervous system in infants. When large amounts of iron and folic acid are consumed, the absorp- tion of zinc is inhibited, and the serum zinc levels are reduced as a result. Because iron and folic acid supplements are com- monly prescribed during pregnancy, pregnant women should be encouraged to consume good sources of zinc daily (see Table 14-1). Women with anemia who receive high-dose iron supple- ments also need supplements of zinc and copper.

low birth weight (LBW)

birth weight of 2500 g or less) and preterm infants.

Dietary Reference Intakes (DRIs)

have been established for the people of the United States and Canada, and are updated regularly. The DRIs include recommendations for daily nutritional intakes that meet the needs of almost all (97% to 98%) of the healthy members of the population. They are divided into age, sex, and life-stage categories (e.g., infancy, pregnancy, and lactation), and they can be used as goals in plan- ning individuals' diets

lactose intolerance

he inability to digest milk sugar (lactose) because of the lack of the enzyme lactase in the small intestine. It is relatively common in adults, particularly African-Americans, Asians, Native Americans, and Inuits (Alaska Natives). Milk consumption may cause abdominal cramping, bloating, and diarrhea in such people, although many lactose-intolerant individuals can tolerate small amounts of milk without symptoms. Yogurt, sweet acidophi- lus milk, buttermilk, cheese, chocolate milk, and cocoa may be tolerated even when fresh fluid milk is not. Commercial lactase supplements (e.g., Lactaid) are widely available to consume with milk, and many supermarkets stock lactase-treated milk. The lactase in these products hydrolyzes, or digests, the lactose in the milk, making it possible for lactose-intolerant people to drink milk. In some cultures it is uncommon for adults to drink milk. For example, Puerto Rican and other Hispanic people may use it only as an additive in coffee. Pregnant women from these cul- tures may need to consume nondairy sources of calcium (Box 14-6). If calcium intake appears low and the woman does not change her diet habits despite counseling, a supplement con- taining 600 mg of elemental calcium may be needed daily. Cal- cium supplements also may be recommended when a pregnant woman has leg cramps that are caused by an imbalance in the calcium-phosphorus ratio. Bone meal is not recommended as a calcium supplement because it may contain lead.

neural tube defects

or failures in closure of the neural tube, are more common in infants of women with poor folic acid intake. Proper closure of the neural tube is required for normal formation of the spinal cord, and the neural tube begins to close within the first month of gestation, often before the woman realizes that she is pregnant. It is estimated that the incidence of neural tube defects could be decreased 50% to 70% if all women had an adequate folate intake during the periconception period All women capable of becoming pregnant are advised to consume 0.4 mg (400 mcg) of folic acid daily in fortified foods (ready-to-eat cereals and enriched grain products) or supplements, in addition to a diet rich in folate-containing foods: green leafy vegetables, whole grains, and fruits

pyrosis

or heartburn, is usually caused by the reflux of gastric contents into the esophagus. This condition can be minimized by the consumption of small, frequent meals, rather than two or three larger meals daily. Because fluids further dis- tend the stomach they should not be consumed with foods. The woman needs to be sure to drink adequate amounts between meals, however. Avoiding spicy foods may help alleviate the problem. Lying down immediately after eating and wearing clothing that is tight across the abdomen can contribute to the problem of reflux.

pica

which is the practice of consuming nonfood substances (e.g., clay, soil, and laundry starch) or excessive amounts of foodstuffs low in nutritional value (e.g., ice or freezer frost, baking powder or soda, and cornstarch), often is influenced by the woman's cultural background

Key components of nutrition care during the precon- ception period and pregnancy include:

• Nutrition assessment that includes appropriate weight for height and adequacy and quality of dietary intake and habits • Diagnosis of nutrition-related problems or risk factors such as diabetes, phenylketonuria (PKU), and obesity • Intervention based on an individual's dietary goals and plan to promote appropriate weight gain, ingestion of a variety of foods, appropriate use of dietary supplements, and physical activity • Evaluation as an integral part of the nursing care provided to women during the preconception period and preg- nancy, with referral to a nutritionist or dietitian as necessary

Factors that contribute to the increase in nutrient needs include the following:

• The uterine-placental-fetal unit • Maternal blood volume and constituents: During pregnancy the total blood volume increases by about 40% to 50% over the nonpregnant state. • Maternal mammary development • Metabolic needs: Basal metabolic rates, when expressed as kilocalories (kcal) per minute, are approximately 20% higher in pregnant women than in nonpregnant women. This increase includes the energy cost for tissue synthesis.