Nutrition Through the Life Cycle: Pregnancy and the First Year of Life

1. 16 Nutrition Through the Life Cycle: Pregnancy and the First Year of Life

2. Nutrition Before Conception • Adequate nutrition is essential for tissue formation, neurological development, bone growth, modeling, and remodeling • Helps to achieve peak physical and intellectual potential in adult life

3. Nutrition Before Conception • Problems related to nutrient deficiency develop early • Neural tube defects: • Related to inadequate folate status • Effects the embryo in the first few weeks • Adequate folate (400 µg daily) before conception can reduce the risks

4. Nutrition Before Conception • Avoid teratogens that cause birth defects: alcohol and illegal drugs • Consult physician about consumption of caffeine, medications, herbs, supplements • Quit smoking

5. Nutrition Before Conception • A healthful diet and appropriate levels of physical activity before conception • Promote optimal body weight • BMI 19.8 to 26.0: best chance of uncomplicated pregnancy and delivery • Lower risk of negative outcomes such as prolonged labor, cesarean section, gestational diabetes, and hypertension

6. Nutrition Before Conception • A man’s nutrition before conception is also important • Sperm number and motility (ability to move) are reduced by alcohol consumption and certain prescription and illegal drugs • Adequate nutrition keeps the immune system strong and promotes fertility

7. Nutrition During Pregnancy • A balanced, nourishing diet throughout pregnancy provides the nutrients needed and: • Supports fetal growth and development • Provides the mother with the nutrients she needs • Minimizes the risks of excess energy intake

8. Nutrition During Pregnancy • Full-term pregnancy (gestation) lasts 38 to 42 weeks: • Three trimesters lasting 13 to 14 weeks each • Zygote: a single, fertilized cell • Embryo: weeks 3 to 8 after fertilization • Fetus: week 9 to birth

9. First Trimester • Zygote travels through the fallopian tube and implants in the wall of the uterus • Development of organs, limb buds, facial features, placenta • Vulnerable to teratogens during this time • Spontaneous abortion (miscarriage) • Placenta provides nutrients via the umbilical cord

14. Second Trimester • Continued growth and maturation • Growth from ~3 inches to over a foot long by the end of the second trimester • Some babies born prematurely (the end of second trimester) survive with intensive neonatal care

15. Third Trimester • Time of intense growth and maturation • Fetus gains ½ to ¾ of its weight • Brain growth is also extensive • Lungs become fully mature • A balanced, adequate diet for the mother continues to be critical

17. Low-Birth-Weight Infants • Likely among undernourished mothers • Low birth weight: baby born weighing <5.5 lb • Increased risk of infections, learning disabilities, impaired physical development, and death in the first year of life • Preterm babies are born before 38 weeks • Infants that are small for gestational age (SGA) are full-term but weigh less than expected for age

19. Weight Gain During Pregnancy • Typically 25−35 lb • Too much weight gain is also risky • Pattern of weight gain is important: • First trimester: 3−5 lb • Second and third trimesters: average 1 lb per week • Weight loss during pregnancy may deprive the fetus of critical nutrients

22. Nutrition During Pregnancy • The requirement for nearly all nutrients increases during pregnancy • Select foods high in nutrient density • MyPyramid Plan for Moms is a useful tool • Pay attention to intakes of: • Macronutrients (energy) • Micronutrients • Fluids

23. Macronutrients • Energy • Second and third trimesters: add 350−450 calories/day • Maximize nutrient density • Safe and physician-approved program of regular moderate physical activity • Proteins and Carbohydrates • 1.1 gm/kg body weight/day of protein • 175 grams/day minimum of carbohydrates

24. Macronutrients • Fat • Same percentage of calories as in non-pregnancy • Limit saturated fat; avoid trans fats • Fat helps newborn regulate body temperature • Omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) is critical for neurologic and eye development

25. Folate Vitamin B12 Vitamin C Vitamin A Vitamin D Calcium Iron Zinc Sodium Iodine Micronutrients • Micronutrients that are most critical during pregnancy include:

27. Folate • Required for cell division • Critical for development of the neural tube (future brain and spinal cord) • Deficiency is associated with neural tube defects (spina bifida, anencephaly) and macrocytic anemia (immature blood cells) • RDA = 400 µg/day for sexually active women • RDA = 600 µg/day for pregnant women

29. Vitamin B12 • Regenerates the active form of folate • RDA = 2.6 µg/day during pregnancy • Absorption more efficient during pregnancy • Sources: animal foods • Fortified foods or supplementation for women on vegan diets

30. Vitamin C • Synthesis of collagen (connective tissues) • Decreased concentration in maternal blood: increased blood volume, vitamin transferred to fetus • Deficiency: preterm births, complications • RDA: 85 mg/day; more if smoking (lowers serum and amniotic fluid levels of vitamin C)

31. Vitamin A • Needs increased by 10% in pregnancy • Deficiency linked to an increased risk of low birth weight, growth problems, preterm delivery • Excess preformed vitamin A exerts teratogenic effects

32. Vitamin D • AI does not increase during pregnancy • Supplements recommended for pregnant women with darkly pigmented skin and/or limited sun exposure who do not regularly drink milk • Excessive vitamin D can cause developmental disabilities in newborns

33. Calcium • RDA = 1,000 mg/day, same as for non-pregnant women • RDA = 1,300 mg/day for pregnant adolescents • Pregnant women absorb calcium more efficiently • Pregnant lactose-intolerant women: calcium-fortified or low-lactose foods

34. Iron • Increased demand for red blood cells • Need increases (third trimester): stores iron in the liver for use during the first few months of life • Iron-deficiency anemia: fetus takes maternal iron • Deficiency increases rate of low birth weight, preterm birth, stillbirth, and death • Heme-rich foods (meat, fish, and poultry), iron-rich legumes, iron-fortified foods with vitamin-C rich foods, iron and vitamin C supplements • RDA for iron during pregnancy: 27 mg per day

35. Zinc • Need increases 38% during pregnancy • Critical for DNA, RNA, protein synthesis • Deficiency: fetal malformations, premature birth, decreased birth size, extended labor • Absorption of zinc from supplements is inhibited by high intakes of non-heme iron (found in iron supplements) • Sources: red meats, shellfish, fortified cereals

36. Sodium • RDA = 1,500 mg/day, same as for non-pregnant women • Excess: fluid retention, bloating, high blood pressure • Increased body fluids are a normal and necessary part of pregnancy • Some sodium needed for fluid balance

37. Iodine • Need for iodine increases significantly • 220 µg/day can be obtained from iodized salt • Sprinkling salt onto food at the table is unnecessary • Balanced, healthful diet will provide all the iodine needed during pregnancy

38. Supplements During Pregnancy • Prenatal multivitamin-mineral supplements are not strictly necessary • Recommended by most doctors • Meeting all nutrient needs requires careful and complex dietary planning • Good insurance for vegans, adolescents • Supplements: to be taken in addition to, not as a substitute for, a nutrient-rich diet

39. Fluids During Pregnancy • Fluid need increases to 3 liters per day • Increased blood volume of mother • Body temperature regulation • Amniotic fluid: protects and cushions fetus • Combat fluid retention, constipation, and dehydration (morning sickness/vomiting) • Prevent urinary tract infections

40. Nutrition-Related Concerns • Morning sickness • Cravings and aversions • Heartburn • Constipation and hemorrhoids • Gestational diabetes • Preeclampsia

41. Morning Sickness • Nausea and vomiting associated with pregnancy • Can occur at any time; often lasts all day • No cure, but symptoms can be reduced • Eat small, frequent meals and snacks • Consume fluids between meals • Well-tolerated: frozen ice pops, gelatin desserts, watermelon, and mild broths

42. Cravings and Aversions • Most crave a certain type of food (sweet, salty) rather than a particular food • Little evidence supports the claim that cravings indicate a deficiency • Pica: craving non-foods (chalk, clay) • Food aversions are common • Strongly woven into family’s belief system

43. Heartburn • Pregnancy hormones relax lower esophageal smooth muscle • Enlarged uterus pushes on the stomach • Avoid excessive weight gain • Eat small, frequent meals; chew food slowly • Wait 1 hour after eating before lying down • Sleep with your head elevated

44. Constipation • Pregnancy hormones cause smooth muscle to relax • Slow colonic movement of food residue • Eat 25−35 g/day of fiber • Drink plenty of fluids • Keep physically active

45. Gestational Diabetes • Insufficient insulin production or insulin resistance increases blood glucose levels • Requires strict diet, physical activity, and/or medication • Risk of delivering a large baby; risk of type 2 diabetes and overweight later in life

46. Hypertensive Disorders • Gestational hypertension: no symptoms • Preeclampsia: sudden increase in maternal blood pressure • Can be fatal if left untreated • Deficiencies in vitamins C and E, calcium, magnesium increase the risk • Treatment: bed rest, medical oversight • The only cure is childbirth

47. Adolescent pregnancy Vegetarianism Caffeine Alcohol Smoking Illegal drugs Food safety Exercise Nutrition-Related Concerns

48. Adolescent Pregnancy • Full physical stature: not yet attained • Higher needs for calories and bone-related nutrients (calcium, phosphorus, magnesium) • Inadequate maternal weight gain • Poor prenatal care; higher rates of prenatal alcohol and drug use • Higher rates of preterm births, low-birth-weight babies, and other complications

49. Vegetarianism • Vegans need more attention to: • Vitamin D (unless regularly exposed to sunlight throughout the pregnancy) • Vitamins B6 and B12 • Calcium, iron, zinc • Supplements containing these nutrients are usually necessary

50. Consumption of Caffeine • Caffeine is a stimulant that crosses the placenta and reaches the fetus • 1 or 2 cups of coffee (200 mg of caffeine) per day is not likely to harm the fetus • Higher amounts may slightly increase the risk of miscarriage and impair fetal growth • Can make one feel full • Considerable calories (if sweetened)