2. Chapter 15 Pregnancy & Lactation

3. Prior To Pregnancy Goals-essential to conception & healthy infant development –Achieve and maintain a healthy body weight –Choose an adequate and balanced diet –Be physically active –Avoid harmful influences Copyright 2005 Wadsworth Group, a division of Thomson Learning

4. Fetal Growth & Development Ovum + sperm  zygote Zygote – the first 2weeks after fertilization –Implantation Embryo – 2 to 8 weeks after conception Fetus – from 8 weeks after conception to full-term Copyright 2005 Wadsworth Group, a division of Thomson Learning

5. Critical Periods- if cell division and number are limited during a critical period full recovery is not possible Copyright 2005 Wadsworth Group, a division of Thomson Learning

7. Critical Periods Neural tube defects –Anencephaly-the neural tube fails to close so the brain is either missing or fails to develop –Spina bifida-incomplete closure of the spinal cord and its bony encasement Folate supplementation reduces the risk Copyright 2005 Wadsworth Group, a division of Thomson Learning

8. Weight Prior To Conception Increased medical risks if a woman is under- or overweight prior to pregnancy Prepregnancy weight affects development of healthy support tissues – placenta, amniotic sac, etc. Prepregnancy weight affects infant birthweight – Infant birthweight is the most potent predictor of infant’s future health & survival Copyright 2005 Wadsworth Group, a division of Thomson Learning

9. Weight Prior To Conception Underweight –Preterm Overweight and obesity –Post term –Cesarean section –Dieting is dangerous because ketosis from fasting/low-CHO diets impairs fetal brain development Copyright 2005 Wadsworth Group, a division of Thomson Learning

10. Weight Gain Copyright 2005 Wadsworth Group, a division of Thomson Learning

11. Weight Gain Copyright 2005 Wadsworth Group, a division of Thomson Learning

12. Weight Gain Copyright 2005 Wadsworth Group, a division of Thomson Learning

13. Nutrient Needs Energy – Extra food energy needed 1. No additional allowance is provided during the 1 st trimester 2. During the 2 nd & 3 rd trimesters RDA + 350-450 kcals/day 3. More if teenager, underweight, very active, or multiple gestation Protein – RDA +25 grams/day (~70 gms); usually not a problem since most diets already exceed recommendation

14. Nutrient Needs Vitamins – Folate & Vitamin B12 needed in large amounts for rapid cell proliferation Folate needed for increased red blood cells and to help prevent neural tube defects 1. Recommendation increases from 400 micrograms/day during childbearing years to 600 micrograms/day during pregnancy usually from supplements Vitamin B-12 – RDA during pregnancy is 2.6 mcg/day; supplements recommended for vegans

15. Nutrient Needs Minerals needed for: 1. Bones & teeth – calcium, phosphorous, fluoride involved in magnesium & fluoride involved in building the skeleton building the skeleton 2. Blood – iron necessary for 50% increase in maternal blood volume and accumulation of fetal iron stores during the 3 rd trimester 3. Protein synthesis- zinc vital for DNA & RNA synthesis

16. Nutrient Needs Calcium – 1200 mg/day recommended to conserve maternal bone mass while supplying fetal needs Flouride – supplements not recommended if water flouridated Iron – increased need cannot be met by diet or existing stores so supplements (30 mg/day) recommended during 2 nd & 3 rd trimesters

17. Copyright 2005 Wadsworth Group, a division of Thomson Learning

18. High-Risk Pregnancies Copyright 2005 Wadsworth Group, a division of Thomson Learning

19. High-Risk Pregnancies Copyright 2005 Wadsworth Group, a division of Thomson Learning

20. Food Assistance Programs WIC Program – helps low income pregnant women & their children (<5 years) obtain needed food and nutrition education for growth & development and to reduce the risks of preterm or low-birth weight infants

21. Maternal Health Preexisting Diabetes or Gestational Diabetes – high blood glucose can lead to fetal (macrosomia) & delivery complications 1. Usually dx’d in 2 nd or 3 rd trimester by glucose tolerance test; screening at 24-28 weeks gestation 2. Dietary control involves avoiding simple sugars, eating small, frequent meals/snacks, and preventing excessive weight gain 3. 1/3 of women will go on to develop diabetes in future

22. Maternal Health Preexisting Hypertension or Preeclampsia– high blood pressure may be preexisting condition or may be pregnancy-induced signaling onset of preeclampsia (condition characterized by high blood pressure, generalized edema, & proteinuria) 1. Control involves good nutrition (esp. calcium) & bedrest

23. Nutrition-Related Concerns Nausea Constipation and hemorrhoids Heartburn Food cravings and aversions- due to hormone-induced changes in sensitivity to taste and smell instead of reflecting true physiological needs Nonfood cravings – laundry starch, clay, soil, ice –Pica is associated with iron deficiency anemia Copyright 2005 Wadsworth Group, a division of Thomson Learning

24. Maternal Discomforts Nausea/Morning Sickness – caused by hormonal changes early in pregnancy (increased levels of hCG) Ways to Alleviate 1. On waking, rise slowly 2. Eat dry toast or crackers in morning 3. Eat small, frequent low-fat meals 4. Avoid strong or offensive food odors Severe cases – hyperemsis gravidarum; usually require rehydration & hospitalization

25. Maternal Discomforts Heartburn – as baby grows, pressure on mother’s stomach increases causing reflux Ways to Alleviate 1. Eat small, frequent meals slowly 2. Drink liquids between meals 3. Avoid spicy or greasy foods 4. Avoid lying down for right after eating and elevate the head while sleeping

26. Maternal Discomforts Constipation – slower GI motility Ways to Alleviate 1. Increase fluid intake to8 glasses a day 2. Eat foods high in fiber (fruits, vegetables, whole-grain cereals) 3. Exercise regularly 4 Use laxatives only as prescribed by a physician; do not use mineral oil because it interferes with the absorption of fat-soluble vitamins

27. Practices Incompatible with Pregnancy 1. Cigarette smoking – restricts blood supply to fetus, impairing fetal nutrition & increases risk of low birth weight and SIDS infants 2. Caffeine – limit to 1 cup “coffee”/day or may lower infant birthweight 3. Medicinal Drugs – prescription meds only with M.D. approval due to risk of birth defects

28. Practices Incompatible with Pregnancy 4. Illicit drugs, such as cocaine or marijuana, also pass through placenta causing toxicity & central nervous system damage 5. Herbal supplements 6. Vitamin/mineral megadoses are toxic 7. Sugar substitutes in moderation 8. Alcohol may cause fetal alcohol syndrome (severe mental & physical retardation) & interferes with transport of nutrients across placenta

29. Fetal Alcohol Syndrome Copyright 2005 Wadsworth Group, a division of Thomson Learning

30. Lactation Mammary glands- secrete milk Prolactin – hormone responsible for milk production Oxytocin-hormone that causes milk to eject Let-down reflex Copyright 2005 Wadsworth Group, a division of Thomson Learning

34. Mother’s Nutrient Needs During Lactation Energy Needs – additional 500 kcals/day needed to produce ~25 oz. milk/day provided by food & fat reserves (stored energy) 1. Breastfeeding can facilitate maternal weight loss 2. Avoid diets - <1200 kcals/day compromises milk production

35. Mother’s Nutrient Needs During Lactation Fluids - >2 qts./day to prevent dehydration Prenatal vitamin supplements routinely prescribed - RDAs same or slightly higher for most nutrients except iron until menstruation resumes

36. Mother’s Nutrient Needs During Lactation Recommendation for protein the same as during pregnancy Vitamins & Minerals – supplements generally recommended to replete maternal stores; prolonged inadequate intakes reduce the quality of the milk Water – 3 L/day to prevent dehydration

37. Lactation Certain foods, esp. with strong or spicy flavors, are avoided only if baby seems sensitive Caffeine may cause irritability & difficulty sleeping Alcohol easily enters breast milk Smoking decreases milk production Medicinal Drugs – most are compatible but need to check with physician for those contraindicated Illicit Drugs – high doses delivered in breast milk

38. Lactation Breastfeeding considered the “gold standard” for infant feeding due to immunologic, health & social benefits Contraindications – Communicable diseases (TB, hepatitis, HIV, etc.) and certain meds/drugs that adversely affect infant

39. Energy & Nutrient Needs Copyright 2005 Wadsworth Group, a division of Thomson Learning

40. Nutrient Needs