Nutrition During Pregnancy PDF

Chapter 4 Nutrition During Pregnancy Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes (cont’d.)...

Chapter 4 Nutrition During Pregnancy Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes (cont’d.) Infant mortality reflects general health and socioeconomic status of a population – Decreases in mortality are related to improvements in social circumstances, infectious disease control, and availability of safe and nutritious food Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes (cont’d.) Low birthweight (LBW), preterm delivery, and infant mortality – High risk of dying in first year of life – Eight percent of births are LBW, yet comprise 66 percent of infant deaths – 11.4 percent are born preterm; account for a large number of infant deaths Copyright © 2017 Cengage Learning. All Rights Reserved.  The Status of Pregnancy Outcomes (cont’d.) Reducing infant mortality and morbidity – Improve birth weight of newborns Studies suggest that the lowest neonatal and infant mortality rates occur between 3,000 – 3,800 grams (6.6 – 8.4 lbs) Less likely to develop heart and lung diseases, diabetes, and hypertension Copyright © 2017 Cengage Learning. All Rights Reserved.  Physiology of Pregnancy Gestational age – Assessed from date of conception – Average pregnancy is 38 weeks Menstrual age – Assessed from onset of last menstrual period – Average pregnancy is 40 weeks Copyright © 2017 Cengage Learning. All Rights Reserved. Copyright © 2017 Cengage Learning. All Rights Reserved.  Physiology of Pregnancy (cont’d.) Maternal physiology – Changes in maternal body composition and functions occur in specific sequence Copyright © 2017 Cengage Learning. All Rights Reserved. The Physiology of Pregnancy and Factors That Affect Dietary Intake During Pregnancy Normal physiological changes during pregnancy – Maternal anabolic phase: first 20 weeks of pregnancy Mother’s body builds capacity to deliver all of the blood, oxygen, and nutrients the fetus required during the second half of pregnancy Mother’s symptoms: increased appetite, increase in anabolic hormones, and decreased exercise tolerance – Catabolic phase: last 20 weeks of pregnancy Mobilization of stored nutrients Mother’s symptoms: increase in catabolic hormones, increase in exercise tolerance Copyright © 2017 Cengage Learning. All Rights Reserved.  Physiology of Pregnancy (cont’d.) Copyright © 2017 Cengage Learning. All Rights Reserved. The Physiology of Pregnancy and Factors That Affect Dietary Intake During Pregnancy Development of the placenta – A large endocrine organ that develops in the uterus within the first several weeks of conception – Responsible for various functions, including: Secreting vital hormones Fighting internal infections/barrier to harmful substances Exchanging nutrients and oxygen from the mother to the fetus Removing waste products from the fetus to the mother’s blood supply  Physiology of Pregnancy (cont’d.) Copyright © 2017 Cengage Learning. All Rights Reserved.  Physiology of Pregnancy (cont’d.) Factors that affect placenta nutrient transfer – Size and charge of molecules – Lipid solubility of particles – Concentration of nutrients in maternal and fetal blood Copyright © 2017 Cengage Learning. All Rights Reserved.  Physiology of Pregnancy (cont’d.) The fetus is not a parasite – Nutrients are first used for maternal needs, then for placenta, and last for fetal needed – The fetus is harmed more than the mother by poor maternal nutrition Copyright © 2017 Cengage Learning. All Rights Reserved. The Physiology of Pregnancy and Factors That Affect Dietary Intake During Pregnancy Changes in hormones – Increased secretion of hormones by the placenta – Expecting mother relies on specific hormones such as progesterone, estrogen, human chorionic gonadotropic (hCG), leptin, and human chorionic somatomammotropin  Physiology of Pregnancy (cont’d.) Copyright © 2017 Cengage Learning. All Rights Reserved. The Physiology of Pregnancy and Factors That Affect Dietary Intake During Pregnancy Changes in body water – Body water increases 7–10 L during pregnancy – Most goes toward building blood and tissues during the first trimester – Plasma volume starts to increase within the first few weeks of pregnancy, increasing from ~ 50 mL during the 10th week of gestation to ~ 800 mL during the 20th week of gestation – Women with high gains in fluid experience more edema and greater weight gain The Physiology of Pregnancy and Factors That Affect Dietary Intake During Pregnancy Maternal nutrient metabolism during pregnancy – Changes occur within the first few weeks of pregnancy – Calcium metabolism occurs with bone turnover and reformation – Increased levels of body water and tissue synthesis require additional sodium and other minerals  Embryonic and Fetal Growth and Development (cont’d.) Four periods of growth and development – Hyperplasia – Hyperplasia and hypertrophy – Hypertrophy – Maturation Copyright © 2017 Cengage Learning. All Rights Reserved. Copyright © 2017 Cengage Learning. All Rights Reserved.  Embryonic and Fetal Growth and Development (cont’d.) Variation in fetal growth are linked to: – Energy, nutrient, and oxygen availability – Conditions that interfere with genetically programmed growth and development – Insulin-like growth factor (IGF-1) is the main fetal growth stimulator Copyright © 2017 Cengage Learning. All Rights Reserved. Pregnancy Weight Gain Rate of pregnancy weight gain – Rate of weight gain not as important as total amount of weight gained – Most weight gain occurs during the second and third trimesters – Women may experience slow rates of weight gain and possibly weight loss throughout pregnancy For normal weight, gain 25-35 lb Pregnancy Weight Gain Figure 3.3 Average Weight distribution during pregnancy. Pregnancy Weight Gain Composition of weight gain – ~ One-third of the weight gained in a normal-weight woman goes to the fetus. – Increased body fat helps to meet the nutritional needs of the mother and the fetus. – Body fat stores provide an average reserve of 30,000 calories for pregnancy and lactation. – Fat storage increases most significantly during the first several weeks of the second trimester and tends to decrease later in pregnancy.  Nutrition and the Course and Outcome of Pregnancy Famine and pregnancy outcome – The Dutch hunger winter (1943-1944) Declined pregnancy rates and lower birth weights – The siege of Leningrad (1942) Increased infertility, infant death rates, and low birth weights – Food shortages in Japan (and other areas) and famine in China Similar to the outcomes above Copyright © 2017 Cengage Learning. All Rights Reserved.  Energy and Nutrient Needs During Pregnancy Nutrient needs vary during the course of the pregnancy – Can be met with healthful diets Energy intake: increased need Carbohydrate intake: 45-65 percent Alcohol and pregnancy outcome: no safe level Protein intake: increased need Need for fat: 33 percent Omega-3 fatty acids, EPA, and DHA: several benefits; follow intake recommendations Copyright © 2017 Cengage Learning. All Rights Reserved.  Energy and Nutrient Needs During Pregnancy(cont’d.) Carbohydrate metabolism – Glucose: preferred fuel for fetus Early pregnancy: high estrogen and progesterone stimulate insulin which increases the glucose conversion to glycogen and fat Late pregnancy: human chorionic somatotropin (hCS) and prolactin inhibit conversion of glucose to glycogen and fat – Diabetogenic effect of pregnancy: results from maternal insulin resistance Copyright © 2017 Cengage Learning. All Rights Reserved. Energy and Nutrient Needs During Pregnancy(cont’d.) Carbohydrate metabolism during pregnancy – 50–80% of fetal energy needs are provided by glucose. – The fetus receives adequate glucose even if maternal glucose intake is not adequate. – Glucose crosses the placenta more readily than other macronutrients. – Insulin sensitivity often decreases by 50–70% in the later months of pregnancy, causing insulin resistance in the mother. Diabetogenic effect of pregnancy Energy and Nutrient Needs During Pregnancy(cont’d.) Protein metabolism during pregnancy – Maternal protein accumulates in the blood, uterus, breasts, fetus, placenta, and amniotic fluid – Proteins support rapid growth of maternal and fetal tissues – Required in high amounts, particularly during the second and third trimesters – A natural decline in total nitrogen excretion likely contributes to meeting increased protein needs – Plasma amino acids/use of branched chain amino acids decrease during pregnancy  Energy and Nutrient Needs During Pregnancy(cont’d.) Pregnancy fat metabolism – Fat stores accumulate in first half – Enhanced fat mobilization in last half – Blood lipid levels increase – Increased cholesterol is used for steroid hormone synthesis and by the fetus for nerve and cell membrane formation ▪ Does NOT increase mother’s or fetus’s risk for atherosclerosis later in life Copyright © 2017 Cengage Learning. All Rights Reserved.  Energy and Nutrient Needs During Pregnancy (cont’d.) Copyright © 2017 Cengage Learning. All Rights Reserved.  Energy and Nutrient Needs During Pregnancy (cont’d.) The need for vitamins and minerals during pregnancy – Folate – Iron – VitA – VitD – Calcium – Sodium Copyright © 2017 Cengage Learning. All Rights Reserved. Nutrition Recommendations and Requirements During Pregnancy Water – Increased risk for dehydration with pregnancy, especially with N/V – Increased needs of ~300 mL/day – Increasing fluid intake can help with prevention of edema – Women in hot climates or who exercise need additional fluids – Urine color can help determine hydration status Nutrition Recommendations and Requirements During Pregnancy Sweeteners – FDA approved: acesulfame K, aspartame, saccharin, sucralose (Splenda) – Consume in moderation – Academy of Nutrition and Dietetics considers artificial and nonnutritive sweeteners safe to consume during pregnancy Common Nutrition Considerations During Pregnancy Caffeine – Passes from mother to fetus – Concerns related to increased risk for preterm birth, low birth weight, gestational diabetes, miscarriage, congenital malformations, and growth retardation – Diuretic and increases heart rate – 200 mg per day is considered safe Common Nutrition Considerations During Pregnancy Lead exposure – Can impact children’s cognitive functions Elevated blood lead levels can be toxic to the developing brain – Interferes with calcium and iron absorption – Cause slowed growth and shorter stature Uterus Exposure To Cd Resulted In Congenital Heart Defects Control Cd 50mg/L Common Nutrition Considerations During Pregnancy Common gastrointestinal disturbances – Pregnant women are susceptible to common GI disturbances including nausea, vomiting, diarrhea, and constipation – Related to physiological, hormonal, and structural changes during pregnancy Common Nutrition Considerations During Pregnancy Nausea and vomiting – Common – Generally starts around the 6th week of pregnancy and stops around the 12th week – Not harmful unless becomes severe – Modifications to diet, eating patterns, and fluid intake can help ease symptoms Common Nutrition Considerations During Pregnancy Diarrhea – Common causes include infectious agents, medications, food poisoning, food intolerances; lactose, fructose, sorbitol, and mannitol intolerances; inflammatory bowel disease (IBD); and irritable bowel syndrome (IBS) – Treatment Rehydration and correction of electrolyte imbalances Dietary changes as needed For IBS: high fiber diet, stool bulking agents, and adequate fluids Common Nutrition Considerations During Pregnancy Heartburn – Relaxation of GI muscles secondary to an increase in estrogen and progesterone Relaxation of the lower esophageal sphincter Stomach contents move into the esophagus, causing heartburn or more severely gastroesophageal reflux disease (GERD) – Pressure from the uterus and fetus can also cause heartburn – Dietary changes can help Common Nutrition Considerations During Pregnancy Gastroesophageal reflux disease – Caused by the impact of fluctuating hormones on the function of the lower esophageal sphincter – Stomach acid easily refluxes into the esophagus causing symptoms – Triggers: eating before bed, intake of fatty or spicy foods, caffeine, mints, chocolate, and side effects of medications – Lifestyle modifications addressing triggers help manage symptoms Common Nutrition Considerations During Pregnancy Constipation – Common, especially in third trimester – Likely due to relaxed musculature of GI tract – Increasing fiber and fluid recommended – Laxatives often not recommended during pregnancy Common Nutrition Considerations During Pregnancy Food safety – Reduced ability to fight off infection during pregnancy – Foodborne illness: Listeriosis especially harmful Can cause miscarriage or stillbirth – Mercury – Hygiene and sanitation Clean, separate, cook, chill Common Nutrition Considerations During Pregnancy Changes in smell and taste – May be related to change in hormones – Two-thirds of pregnant women report they experienced a heightened sense of smell Cravings and aversions are very common during pregnancy Goal of clinicians should be to help women meet their nutrient needs Promoting Healthy Lifestyles Exercise recommendations – Moderate to vigorous cardiovascular activity along with weight bearing exercise is beneficial – Reduces risk of gestational diabetes, preeclampsia, preterm birth, and helps maintain appropriate weight gain, and can prevent lower back pain – High risk pregnancy may require reduction/abstinence from exercise – Recommendation: at least 30 minutes five times each week, or for a total of 150 minutes a week Promoting Healthy Lifestyles Food insecurity and hunger Mental health – Anxiety and depression most common – Can cause poor health outcomes for mother and baby – Nutrient deficiencies may contribute to mental health concerns and a well-balanced diet is imperative