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Perspectives in Nutrition, 8th Edition Chapter 16 Outline: Nutritional Aspects of Pregnancy and Breastfeeding After studying this chapter, you will be able to: 1. Describe factors that predict a successful pregnancy outcome. 2. List major physiological changes that occur in the body during pregnancy and describe how nutrient needs are altered. 3. Specify the optimal weight gain during pregnancy for adult women. 4. Describe the special nutritional needs of pregnant and lactating women, summarize factors that put them at risk for nutrient deficiencies, and plan a nutritious diet for them. 5. Identify nutrients that often need to be supplemented during pregnancy and lactation and explain the reason for each. 6. Discuss potential nutrition-related problems that occur during pregnancy and suggest techniques for coping with these problems. 7. List substances and practices to avoid during pregnancy and lactation and describe why they are harmful. 16.1 Pregnancy A. General 1. Gestation: conception to birth, usually 40 weeks 2. Favorable pregnancy outcome a. Live, healthy infant b. Full-term gestation period (longer than 37 weeks) c. Infant weighs more than 5.5 pounds d. Permits the mother to return to her pre-pregnancy status 3. Preterm birth: before 37 weeks gestation 4. Low birth weight: weighing less than 5.5 pounds (2500 g) 5. Small for gestational age: infants suffering from prenatal growth retardation, weigh less than expected for gestational age 6. Average weight of a healthy, full-term infant: 7.5 pounds 7. Complications associated with preterm birth, low birth weight, and/or prenatal growth retardation a. Increased risk of infant death b. Medical complications i. Handicaps ii. Illnesses iii. Temperature regulation iv. Growth v. Development c. Nutritional complications i. Poor blood glucose control ii. Increased nutrient and calorie needs iii. B. C. Risk of nutrient deficiencies - many nutrient stores are deposited during last 4 - 6 weeks of gestation iv. At risk of developing more body fat and less lean mass during childhood Prenatal Developmental Stages: Conception, Zygotic, Embryonic, and Fetal (see Figure 16-4) 1. Conception: sperm unites with ovum 2. Zygotic stage: 30 hours after conception - 2 weeks after conception 3. Embryonic stage: 2 weeks after conception - 8 weeks after conception a. By the end of the embryonic stage, the embryo is complex (e.g., major organs are in place and some have started to function), but only the size of a pea 4. Fetal period: 8 weeks after conception - birth a. 90% of all fetal growth occurs during last 20 weeks of gestation b. Average length at birth: 20 - 22 inches c. Average weight at birth: 7 - 8 pounds d. Body fat is deposited subcutaneously (about 16% by 38 weeks) to help regulate body temperature 5. Trimesters: three 13 -14 week periods into which pregnancy is arbitrarily divided 6. Critical Periods: finite window of opportunity for cells to develop in a particular organ or tissue a. Most occur during first trimester b. Nutrient deficiencies, nutrient excesses, pathogens, trauma, radiation, tobacco smoke, and toxins can interfere with normal development, resulting in abnormalities or spontaneous abortion c. Detrimental prenatal environment can adversely affect development at any stage of development, but damage is most catastrophic during critical periods d. Some nutrient deficits can be partly reversed by adequate nutrition after birth 7. Spontaneous abortion: naturally occurring premature termination of pregnancy prior to 20 weeks of gestation a. Early spontaneous abortions (i.e., miscarriages) usually result from genetic defect or fatal error in fetal development b. Half or more of all pregnancies end in miscarriages, sometimes before woman knows she is pregnant c. 15 - 20% more pregnancies end before normal delivery (after 20 weeks gestation) Nourishing the Zygote, Embryo, and Fetus 1. Zygote a. Absorbs secretions from uterine glands b. Digests some of uterine lining 2. Embryo a. b. c. d. e. 16.2 Placenta delivers nourishment to developing organism through umbilical cord, which contains 2 arteries and 1 vein to transfer nutrients, oxygen, and wastes to/from maternal blood supply Maternal and fetal blood supplies do not mix, but nutrients, oxygen, and wastes are exchanged by absorption mechanisms similar to GI tract Placenta synthesizes fatty acids, cholesterol, and glycogen Placenta produces hormones that regulate fetal metabolism and physiological changes that support pregnancy in the mother Placenta’s size and ability to support optimal fetal growth depend on mother’s nutritional status Nutrient Needs of Pregnant Women A. General 1. Mother needs to consume more nutrient-dense foods 2. More efficient use of some nutrients (e.g., protein) 3. Better absorption of some nutrients (e.g., calcium, iron) 4. Decreased excretion of some nutrients (e.g., zinc, riboflavin) B. Energy Needs 1. Extra calories support growth of maternal and fetal tissues and extra workload on mother’s heart, lungs, and other organs 2. Calorie needs a. First trimester: few extra calories above pre-pregnancy needs b. Second trimester: 350 extra calories above pre-pregnancy needs c. Third trimester: 450 extra calories above pre-pregnancy needs 3. Estimates of additional calorie needs may vary a. Pre-pregnancy weight b. Maternal age c. Physical activity level 4. Consequences of calorie restriction during pregnancy a. Small for gestational age b. Infant mortality c. Thrifty metabolism in offspring, which elevates risk of obesity and type 2 diabetes d. Greater risk of heart disease, high blood cholesterol, diabetes, high blood pressure, and impaired immune function in offspring 5. Iodine a. Ensures adequate production of thyroid hormone b. Thyroid deficiency during pregnancy can lead to cretinism or other serious birth defects c. Use of iodized salt can prevent deficiency C. Nutrients Needed for Building New Cells 1. Protein a. More than 50% above needs of non-pregnant women 2. 3. 4. b. In U.S. and Canada, protein intake is plentiful c. Protein supplements are unnecessary and not recommended Essential fatty acids a. Required for normal fetal growth and development, particularly of brain and eyes b. Sufficient EFAs, particularly DHA, may improve gestation duration and infant birth weight, length, and head circumference c. Many women need to decrease the ratio of n-6:n-3 fatty acids d. Minimize trans fatty acid intake during pregnancy Zinc a. Intake of pregnant and non-pregnant women is often low, but deficiencies are uncommon b. Consequences of severe zinc deficiency i. Birth defects ii. Fetal growth retardation iii. Premature birth iv. Spontaneous abortion v. Prolonged labor vi. Maternal bleeding vii. Maternal infections viii. Pregnancy-induced hypertension/preeclampsia c. Potential causes i. Low dietary zinc intake ii. High fiber intake iii. High iron intake d. Factors that impair transfer of zinc from placenta to fetus i. Use of certain medications ii. Cigarette smoking iii. Alcohol abuse iv. Strenuous exercise Folate a. Roles during pregnancy i. DNA synthesis ii. Cell formation (e.g., RBCs) b. Consequences of deficiency i. Anemia ii. Premature birth iii. Low birth weight iv. Fetal growth retardation v. Poor placenta development vi. Neural tube defects vii. Spontaneous abortion viii. Heart defects (1 in 110 newborns) 5. 6. ix. Down syndrome c. Neural tube defects (see Figure 16-6) i. Neural tube develops into brain and spinal cord ii. Spina bifida results from incomplete closure of tube during early gestation; leads to spinal defects, dislocated hips, or other handicaps iii. Anencephaly results from poor brain formation; leads to infant death d. In addition to eating a folate-rich diet, use of multivitamin and mineral supplement is advised before becoming pregnant to ensure adequate folate status e. History of NTDs may necessitate folic acid supplementation in excess of RDA; consult health care provider to prevent masking a B-12 deficiency f. Folic acid (form in supplements and fortified foods) is absorbed twice as well as folate that naturally occurs in foods g. Fortification of grains with folate has led to17% reduction in NTDs since 1998 Vitamin B-12 a. Roles during pregnancy i. DNA synthesis ii. Cell formation b. Consequences of deficiency i. NTDs ii. Anemia c. Potential causes for deficiency i. Vegetarian diet; requires B-12 supplementation Iron a. Needs rise significantly during pregnancy b. Roles of iron during pregnancy i. RBC formation (increased maternal supply) c. Many women consume insufficient iron and have poor iron status prior to conception d. Maternal adaptations to conserve iron i. Absorption increased up to 3 times during pregnancy ii. Menstruation ceases e. Supplementation i. Many experts advise 30 mg/d ii. May decrease absorption of zinc and copper iii. May decrease appetite iv. May cause nausea or constipation v. Avoid coffee or tea with supplements to limit polyphenols, which hinder absorption vi. D. E. Eat foods rich in vitamin C or heme iron with iron supplements to enhance absorption f. Consequences of deficiency during pregnancy i. Suboptimal delivery of oxygen to fetus ii. Low birth weight iii. Premature birth iv. Infant death due to low infant iron stores v. Preeclampsia vi. Labor and delivery complications vii. Increased risk of maternal death g. Anemia of pregnancy: normal decrease in ratio of RBCs to total blood volume due to hemodilution (physiological anemia) i. RBCs increase 20 - 30%, whereas blood volume increases 50% ii. No danger to health of mother or fetus Nutrients Needed for Bone and Tooth Development 1. Calcium a. AI does not increase during pregnancy because maternal absorption efficiency increases b. Failure to meet AI puts mother at risk for osteoporosis later in life because calcium for fetal development is drawn from mother’s bones regardless of her intake c. Populations at risk for calcium deficiency i. Vegans ii. Pregnant teens iii. Women at risk of pregnancy-induced hypertension iv. Avoidance of dairy products d. Supplementation may be necessary 2. Vitamin D a. Consequences of deficiency for mother i. Osteopenia b. Consequences of deficiency for fetus i. Rickets ii. Poor growth iii. Inadequate calcification of bones and teeth c. Populations at risk for vitamin D deficiency i. Avoidance of milk ii. Limited exposure to sunlight d. Supplementation may be necessary, particularly during winter months in northern latitudes Pregnant Women Do Not Have an Instinctive Drive to Consume More Nutrients 1. Cravings and food aversions are likely due to hormonal changes or family traditions; no evidence that they result from nutrient deficiencies 2. 3. 4. 16.3 Cravings and aversions won’t affect nutrient status as long as overall diet provides adequate nutrients and calories To cope with cravings, eat small amounts of desired foods with regular meals or snacks; avoid limiting dietary variety Pica: eating non-food substances (e.g., laundry starch, coal, clay, rubber) a. Occurs among men and women in many racial and ethnic groups b. Seems to be more of a family tradition than an internal drive c. Dangers outweigh potential benefits i. Ingestion of toxins ii. Intestinal blockages iii. Parasites and pathogens iv. Malnutrition v. Obesity vi. Premature birth vii. Low birth weight viii. Poor fetal nutrient stores ix. Maternal and fetal death Diet and Exercise Plan for Pregnancy A. General 1. Nutrient needs increase more than energy needs, so food choices must be nutrient dense 2. MyPyramid eating plans supports successful pregnancy outcome a. First trimester i. 2200 kcal ii. Milk: 3 c iii. Meat and beans: 6 oz-equivalents iv. Vegetables: 3 c; 1 c should be rich in vitamin C and 1 c should be rich in folate v. Fruit: 2 c vi. Grains: 7 oz-equivalents; emphasize whole grains vii. Oils: 6 t vegetable oil, especially to provide EFAs viii. Discretionary calories: up to 300 kcal for weight maintenance b. Second and third trimesters i. 2600 kcal ii. Milk: 3 c iii. Meat and beans: 6 ½ oz-equivalents iv. Vegetables: 3 ½ c v. Fruit: 2 c vi. Grains: 8 oz-equivalents vii. Oils: 7 tsp vegetable oil viii. Discretionary calories: up to 400 kcal for gradual weight gain B. Prenatal Vitamin and Mineral Supplements 1. 2. 3. 4. 16.4 Routinely prescribed, especially for a. Women with a history of frequent dieting b. Teenagers c. Vegans d. Low income e. Underweight f. Smoke g. Abuse of alcohol or illegal drugs h. Carrying multiple fetuses i. Restricted dietary variety Over-the-counter or prescription (for high iron or folic acid contents) Megadoses can be detrimental to maternal and fetal health a. Iron b. Zinc c. Selenium d. Vitamin A (teratogenic above 3000 µg/d) e. Vitamin B-6 f. Vitamin C g. Vitamin D Some physicians only prescribe iron supplements during 2nd and 3rd trimesters and/or individual vitamins or minerals to cover deficiencies (e.g., B-12 for vegans) Nutrition-Related Factors Affecting Pregnancy Outcome A. Maternal Pre-pregnancy Weight 1. Pregnancy complications can result when mother is either underweight or overweight at start of pregnancy 2. Problems associated with high pre-pregnancy weight a. Risks for infant i. Increased risk of birth defects ii. Increased risk of infant death iii. Increased risk of obesity in childhood b. Risks for mother i. High blood pressure ii. Gestational diabetes iii. Difficult delivery 3. Problems associated with low pre-pregnancy weight (BMI < 19.8) a. Problems are likely due to lighter placenta and decreased maternal nutrient stores (especially iron) b. Increased risk of low birth weight c. Increased risk of premature birth 4. Pre-pregnancy weight and nutrient stores affect fertility a. Underweight may lead to amenorrhea, which reduces ovulation b. B. C. Low nutrient intakes (e.g., zinc, folate, vitamin C) affect sperm production Maternal Weight Gain 1. Maternal weight gain supports fetal and maternal growth and prepares mother’s body for lactation (see Figure 16-7) a. Maternal fat stores: 4 - 8 lb b. Uterus and breasts: 6 lb c. Blood: 4 lb d. Fetus, placenta, and amniotic fluid: 8 lb 2. Recommended weight gain for optimal health of both mother and infant based on pre-pregnancy BMI (see Table 16-4) a. Low (BMI <19.8): 28 - 40 lb b. Normal (BMI 19.8 - 25.9): 25 - 35 lb c. High (BMI 26 -29): 15 - 25 lb d. Obese (BMI >29): 15 lb or more 3. Shorter women, women who were malnourished during childhood, and women who experienced growth retardation should aim for the lower end of ranges of weight gain 4. Adolescents should aim for the upper end of ranges because they tend to deliver lighter babies than older mothers 5. Women carrying multiple fetuses should gain more weight a. Twins: 35 - 45 lb b. Triplets: 50 lb 6. Although African-American women have increased risk of delivering LBW infants, there is no current recommendation for them to gain weight at the high end of ranges 7. Consequences of gaining too little weight during pregnancy a. Premature birth b. Small for gestational age c. Infant death 8. Consequences of gaining too much weight during pregnancy a. Large babies b. Increased delivery complications c. Infant mortality d. Postpartum maternal weight retention Pattern of Maternal Weight Gain 1. First trimester: 2 - 4 lb, accounting for growth of breasts and uterus 2. Second and third trimesters: ~1 lb/week at a slow, steady rate a. Underweight women should gain slightly more b. Overweight women should gain slightly less 3. Low weight gain during 2nd and 3rd trimesters increases chances of fetal growth retardation 4. Low weight gain during the 3rd trimester raises risk of premature birth 5. D. E. F. If weight gain deviates from recommendations, make adjustments to get back on track (e.g., slow rate of weight gain), but don’t try to lose weight while pregnant 6. Sudden weight changes during pregnancy may signal health problem (e.g., pregnancy-induced hypertension) Young Maternal Age 1. Concerns for teen mothers a. Physical immaturity: physical maturation continues for 5 years after menarche (average age of menarche is 13 y) b. Teen years demand high nutrient intake, and supporting nutrient needs of both mother and infant is challenging c. Underweight at start of pregnancy, gain too little weight during pregnancy d. Inadequate prenatal care 2. Risks for infants of teen mothers a. Premature birth b. Prenatal growth retardation c. Infant death d. Stillbirth e. Spontaneous abortion Maternal Eating Patterns 1. Calorie restriction a. Ketones are poorly used by fetal brain and may slow its development b. Women should consume regular meals and avoid fasting more than 12 hours c. Weight loss should never be attempted during pregnancy d. Carbohydrate intake should be at least 175 g/d to prevent ketosis 2. Women with eating disorders, diabetes, or phenylketonuria should work with health-care providers to ensure diets meet their own and their babies’ needs 3. Vegan diets: careful planning to ensure adequate protein, vitamin D, vitamin B-6, iron, calcium, zinc, and vitamin B-12 4. Use of prenatal multivitamin and mineral supplement helps fill micronutrient gaps; avoid taking iron and calcium together Maternal Food Supply 1. Environmental contaminants a. Routes of contamination i. Food containers ii. Polluted water iii. Farming practices iv. Food preparation practices b. Contaminants of particular concern i. Lead: leaded crystal glasses or some dishes, solder on copper pipes ii. Mercury: fish from polluted waterways iii. iv. 2. 3. 4. Polychlorinated biphenyls: fish from polluted waterways Pesticides: fish from polluted waterways, unwashed fruits and vegetables c. Recommendations i. Avoid swordfish, shark, king mackerel, and tilefish ii. Limit intake of other fish and shellfish to 12 oz (no more than 6 oz of albacore tuna) per week iii. Thoroughly wash fruits and vegetables Foodborne illness a. Pathogens of greatest concern i. Listeria monocytogenes can cause spontaneous abortion, premature delivery, stillbirth, and infections in newborn ii. Toxoplasmosis b. Foods to avoid i. Raw sprouts ii. Unpasteurized milk and juices iii. Raw or undercooked meat and eggs iv. Soft cheeses c. Other recommendations i. Thoroughly cook leftovers and meats (including processed meats) ii. Avoid litter boxes, kittens, and birds iii. Carefully wash produce to remove soil iv. Thoroughly cook all meat Caffeine a. Sources i. Coffee ii. Tea iii. Some soft drinks iv. Chocolate v. Some medications (e.g., headache and cold remedies) b. Consequences of intakes >500 mg/d i. Reduced fertility ii. Increased fetal heart rate iii. Decreased blood flow to placenta iv. Decreased absorption of certain nutrients (e.g., calcium, iron, zinc) v. Withdrawal symptoms in newborn c. Recommendations: limit caffeine consumption to 300 mg/d (~3 c coffee or 4 c caffeinated soft drinks) Food additives a. Phenylalanine in non-caloric sweeteners can disrupt fetal brain development for mothers with PKU G. Maternal Lifestyle 1. Women should exercise the most caution while trying to conceive and during the first trimester 2. Alcohol a. Consequences of alcohol consumption i. Impaired fertility ii. Displacement of nutrient-dense foods iii. Slowed delivery of nutrients and oxygen to embryo or fetus, thus retarding growth and development b. Consequences are most severe during first trimester, but damage can occur at any time during pregnancy c. 30/1000 births are affected by alcohol-related defects d. Fetal alcohol syndrome i. Facial malformations ii. Growth retardation iii. CNS defects (e.g., mental retardation, small brain size) e. Fetal alcohol effects i. Learning disabilities ii. Short attention span iii. Hyperactivity iv. Physical birth defects f. Alcohol freely crosses the placenta, intensity is magnified by small fetal size and inability to metabolize alcohol g. There is no known safe amount of alcohol consumption during pregnancy; total abstinence is recommended 3. Drugs (over-the-counter, prescription, or illegal) a. Common culprits i. Aspirin ii. Hormone ointments iii. Nose drops iv. Cold medications v. Rectal suppositories vi. Weight-control pills vii. Medications prescribed for previous illnesses viii. Marijuana ix. Cocaine x. Accutane b. Consequences i. Depleted nutrient stores ii. Altered nutrient absorption iii. Decreased desire to eat iv. Reduced fetal blood flow v. Birth defects 4. 5. 16.5 Herbal and botanical products a. May exert potent, drug-like effects b. All herbal and botanical products should be used with caution under the guidance of a health-care professional Nicotine and carbon monoxide a. Consequences i. Restricted blood flow ii. Reduced zinc status, which impairs growth iii. Premature birth iv. Growth retardation v. Birth defects vi. Childhood cancer vii. Sudden infant death b. Other factors that compound the effects of smoking i. Low maternal pre-pregnancy weight ii. Low weight gain during pregnancy iii. Poor maternal diet Lactation A. General 1. Preparation begins in puberty: hormones stimulate breast development a. Fat deposition b. Development of lobules and ducts 2. In early pregnancy, hormones secreted by placenta cause milk-producing glands to mature and lactiferous ducts to become more branched 3. Following childbirth, pituitary hormones initiate milk production (prolactin) and release (oxytoxin) 4. Without infant suckling, milk production ceases B. Milk Production 1. Birth and infant suckling stimulate manufacture and secretion of prolactin from pituitary gland 2. Prolactin stimulates mammary gland to synthesize milk, which promotes milk production 3. Lactation must be initiated shortly after birth or milk supply will cease 4. To establish lactation between mother and infant, sucking should take place every 2 - 3 hours for 15 - 20 minutes on each breast 5. Milk production parallels infant demand a. Continued suckling stimulates continued lactation, which can be maintained for years b. Women are able to successfully breastfeed twins or triplets 6. Weaning should be gradual to avoid painful engorgement (e.g., eliminate 1 feeding each week) 7. Milk Types and Composition a. b. c. 16.6 Colostrum: thin, yellowish, immature milk that appears near the end of pregnancy or just after birth i. Richer in protein, minerals, and vitamin A than mature milk ii. Lower in carbohydrate and calories than mature milk iii. Contains antibodies and immune system cells that pass through the infant’s immature GI tract and impart immune defenses during the first few months of life iv. Lactobacillus bifidus factor encourages growth of L. bifidus and limits growth of potentially toxic bacteria in infant’s GI tract v. Laxative effect Transitional milk: contains more fat, lactose, water-soluble vitamins, and calories than colostrum Mature milk i. Thin, watery, bluish tinge ii. Provides 20 kcal/oz iii. Meets all nutrient needs of growing infant, with exceptions of vitamin D and iron Nutrient Needs of Breastfeeding Women A. General 1. Nutrient needs and calorie demands of lactation mostly exceed those of pregnancy 2. Iron needs are slightly lower than pregnancy and prepregnancy RDAs because breast milk contains little iron and menstruation is usually delayed for about 6 months B. Maternal Nutritional Status 1. Dietary sources and maternal storage of nutrients keep composition and volume of milk at consistent levels 2. Maternal malnutrition must be severe before lactation will cease 3. Excessive intake of macronutrients and fluids usually have no effect on milk composition 4. Proportions of dietary fatty acids may affect milk fat composition 5. Excessive vitamin or mineral intake may increase mineral content of milk; may have drug-like effects 6. Nutrients that are commonly inadequate in diets of lactating women a. Calcium b. Magnesium c. Zinc d. Folate e. Vitamin B-6 7. Adequate fluid intake is vital to prevent dehydration: fluid requirements increase by 32 oz/d (above the 72 oz recommended for non-pregnant women) 8. Calorie needs for milk production a. C. 16.7 Average breastfeeding woman uses 800 kcal/d during the first 6 months of lactation to produce 750 ml milk/d b. 400 - 500 kcals/d from dietary sources (following same meal plan as for 2nd and 3rd trimesters) allows for gradual loss of stored fat, especially when woman continues breastfeeding for 6 months and does some physical activity c. Overweight women can rely entirely on stored fat d. Severe calorie restriction that leads to weight loss > 4 lb/month can decrease milk production e. After 6 months of lactation, dietary intake should support calorie needs, especially if woman has lost pregnancy weight f. BMI <18.5 will likely compromise milk production Food Choices during Lactation 1. Single food items have little effect on quality or amount of milk production 2. Some cultures believe that food items (e.g., garlic, beer) increase milk production, but evidence does not support these beliefs 3. Fortified breakfast cereal or multivitamin and mineral supplement is advised to meet nutrient needs 4. Sufficient omega-3 fatty acids (fish or supplements) are required for secretion in breast milk to aid in development of infant’s nervous system; follow recommendations for fish intake set for pregnancy 5. Avoidance of peanuts or peanut butter may decrease risk of peanut allergy for infants at high risk for food allergies Factors Affecting Lactation A. General 1. Benefits for infant a. Nutrition b. Immunity c. Psychology 2. Benefits for mother a. Reduced risk of ovarian and premenopausal breast cancers b. Bone remineralization exceeding pre-lactation levels c. Weight loss d. Quicker return of uterus to pre-pregnancy state e. Less postpartum bleeding f. Delayed ovulation, leading to decreased chances of pregnancy in the short term g. Reduced risk of metabolic syndrome later in life B. Maternal Weight 1. Obesity may hinder initiation and continuation of breastfeeding 2. Supplementing human milk with infant formula may be necessary until milk supply increases C. D. E. F. Maternal Age 1. Infants of adolescent mothers may grow more slowly than infants of older mothers 2. Teen mothers may need assistance to meet their own nutritional needs in addition to those of the infant Maternal Eating Patterns 1. Occasional poor dietary intake is no cause for concern 2. Chronic nutrient and calorie inadequacy may deplete maternal nutrient stores and negatively affect milk supply Maternal and Infant Health 1. Inborn error of metabolism in infant may rule out breastfeeding a. PKU b. Galactosemia 2. Infectious diseases may be transmitted through human milk a. Tuberculosis b. Hepatitis C 3. Some chronic diseases are incompatible with breastfeeding a. Cancer treated with chemotherapy b. HIV; however in regions of the world where infectious disease and malnutrition are primary causes of death, risk of not breastfeeding outweighs risk of possible transmission of HIV infection 4. Breast surgery may prevent milk production or secretion Sociocultural Factors 1. Breastfeeding is a learned skill; new mothers require: a. Education b. Social support (including spouse/partner) c. Help from knowledgeable health professionals (e.g., lactation consultants) 2. Factors that limit breastfeeding success a. Lack of information b. Lack of confidence c. Lack of role models and/or inadequate support system 3. Sources of accurate breastfeeding knowledge a. Lactation consultants b. Le Leche League offers classes and information 4. Facts about breastfeeding a. Practically all women are physically capable of breastfeeding b. Anatomical problems (e.g., flat or inverted nipples) can be corrected c. No relationship between breast size and quality or amount of milk produced d. Women can continue to breastfeed even after returning to work or school i. Alternate breastfeeding with bottle feeding ii. iii. iv. v. vi. vii. G. H. Manually express or mechanically pump breast milk into sterile container; store in refrigerator or freezer Breastfeeding in public can be done modestly No state has law prohibiting breastfeeding, but indecent exposure may be an offense in some states Infant is receiving adequate milk if the baby has 6+ wet diapers/d and grows normally Although ovulation is delayed by breastfeeding, it is no substitute for reliable birth control Even premature and/or LBW infants can be breastfed, sometimes requiring pumping and fortification with certain nutrients (e.g., calcium, phosphorus, sodium, and protein) Maternal Food Supply 1. Environmental contaminants can appear in milk; effects on infant are unknown a. Avoid freshwater fish from polluted waters b. Carefully wash and peel fruits and vegetables c. Remove fatty portions of meat because contaminants are concentrated in fat tissue d. Avoid rapid weight loss because toxins that have accumulated in fat tissue may be secreted into breast milk 2. Local health department has information regarding toxic wastes and other contaminants 3. Caffeine may cause irritability, tension, and sleeplessness in infants; avoid caffeine or limit to 1 - 2 c/d 4. Some foods impart unpleasant flavors (e.g., cabbage, chocolate); mothers should pay attention to infants’ behavior Maternal Lifestyle Choices 1. Alcohol, drugs, herbal and botanical products, and nicotine are secreted into breast milk 2. Although amount in breast milk may be small, dose may be potent for small infant 3. Alcohol a. Reduces milk output b. Causes infants to drink less and have disrupted sleep patterns c. Best advice is to avoid alcohol during lactation, but limiting intake and waiting 3 - 4 hours before nursing are generally safe d. Amount of alcohol in breast milk peaks 30 - 60 minutes after ingestion, then declines 4. Medications should be used with caution 5. Illegal drugs (e.g., marijuana, cocaine) should always be avoided a. Depress milk production b. Transmitted to infant via breast milk, slowing development and causing vomiting, tremors, breathing difficulties, and convulsions 6. 7. c. Drug addicts should not breastfeed their infants Herbal and botanical products should be used with caution; pass into breast milk Smoking and secondhand smoke a. Lower milk production b. Lower infant weight gain c. Nicotine can cause vomiting, slow breathing, increased blood pressure, apathy d. Benefits of breastfeeding still outweigh risks of nicotine exposure 16.8 Global Nutrition: Pregnancy and Malnutrition A. Effects of undernutrition are profound during pregnancy and fetal life 1. In Africa, women have 1/20 chance of death from pregnancy (compared to 1/8000 in North America) 2. Premature birth, low birth weight a. Reduced lung function b. Weakened immune system c. Increased risk of premature death d. Growth and developmental problems B. Calorie restriction (e.g., 1000 kcal/d) limits fetal growth and development 1. Famine in Africa 2. Food shortages during WWII in Holland 3. Food shortages during siege of Leningrad 16.9 Medical Perspective: Nutrition-Related Physiological Changes of Concern During Pregnancy A. Heartburn 1. Possible causes a. Expanding uterus crowds abdominal organs, leading to reflux b. Hormones of pregnancy relax lower esophageal sphincter 2. Recommendations a. Eat several small meals b. Avoid spicy and fatty foods c. Limit caffeine and chocolate d. Consume liquids between meals e. Wait several hours to lie down after eating f. Elevate head of bed g. Use of antacids may cause constipation, excessive sodium intake, etc; consult health-care provider before using them B. Constipation 1. Possible causes a. Hormones of pregnancy relax intestinal muscles to slow digestion and increase nutrient absorption, but increased absorption of water can lead to hard, dry stools b. Growing fetus compresses GI tract 2. 3. C. D. May lead to hemorrhoids Recommendations a. Consume high fiber foods (28 g/d) b. Drink more fluids (10 c/d) c. Exercise d. Adjust dosage of iron supplements e. Use of stool softeners and laxatives should be guided by health-care professional Nausea and Vomiting 1. Sometimes called morning sickness, but can occur at any time of day 2. Potential causes a. Increased sense of smell b. Iron in prenatal supplements 3. Recommendations a. Breathing cool, fresh air b. Avoid offensive odors c. Avoid large fluid intakes early in morning d. Avoid empty stomach e. Eat specific foods that ease symptoms (e.g., starchy, bland foods) f. Postponing use of iron-containing supplements until 2nd trimester 4. Usually eases by 2nd trimester, but 10 - 20% of cases develop into hyperemesis gravidarium a. May lead to dehydration, malnutrition, and electrolyte imbalances b. May require medications or hospitalization Edema 1. Potential causes a. Placental hormones cause fluid retention b. Expansion of blood volume c. Enlarging uterus compresses blood vessels in the legs (edema in lower legs is common and expected) 2. If edema is accompanied by high blood pressure, protein in the urine, or if edema fails to subside with elevation of feet, this may be a sign of pregnancy-induced hypertension