chapter 17: life cycle nutrition: pregnancy through infancy

© 2010 Pearson Education, Inc.

Chapter 17: Life Cycle Nutrition: Pregnancy through Infancy


Stages of Pregnancy and Importance of the Placenta During pregnancy, the diet must support the health of a

woman and her growing baby Full-term pregnancy averages 38 weeks from conception

to birth (divided into three trimesters)

Figure 17.1

Stages of Pregnancy and Fetal Development


Stages of Pregnancy and Importance of the Placenta Nutrients are delivered to and wastes are transported from

the developing embryo through the placenta• Prevents passage of red blood cells, bacteria, and many

large proteins from mother to fetus• Alcohol, drugs, and other potentially harmful substances

can cross the placenta• Releases hormones required to support the physiological

changes of pregnancy

Figure 17.2

The Placenta


Stages of Pregnancy and Importance of the Placenta Critical periods impact fetal development

• Periods of rapid cellular activity are highly vulnerable to nutritional deficiencies, toxins, and other insults- Famine associated with a high cumulative incidence of

heart disease- Inadequate iron during early pregnancy associated

with poor cognitive development• Metabolic or fetal programming may be able to alter

how genes are expressed during critical periods of development

Figure 17.3

Critical Periods of Development


Quick Review A healthy pregnancy lasts 38 weeks and is divided into

three trimesters The placenta is the site through which the developing fetus

accesses the mother’s organ systems for respiration, absorption, and excretory purposes

Harmful toxins or inadequate nutrition can cause irreversible damage to the fetus, especially during critical periods

Metabolic programming examines the interaction of the prenatal environment on genetic and other factors to produce permanent change


Nutrients and Behaviors Are Important for a Healthy Pregnancy—The Father Before conception, fathers-to-be need to eat well for

healthy sperm production• Smoking, alcohol and drug abuse, and obesity are

associated with decreased sperm production and function• Zinc, folate, and antioxidants are associated with healthy

sperm


Nutrients and Behaviors Are Important for a Healthy Pregnancy—The Mother Before conception, mothers need to adopt a healthy

lifestyle• Attain a healthy weight before conception

- Obesity and overweight are associated with infertility, pregnancy complications, potential birth defects

- Underweight women are at risk of delivering low birth weight or small for gestational age babies

• Get plenty of folic acid–400 micrograms daily- Reduces risk of neural tube defects

• Moderate fish and caffeine consumption


Nutrients and Behaviors Are Important for a Healthy Pregnancy—The Mother

• Avoid cigarettes, alcohol, and illicit drugs- Smoking increases the risk of infertility, a low birth

weight baby, stunted growth or intellectual development, and sudden infant death syndrome (SIDS)

- Drinking alcohol during pregnancy can lead to fetal alcohol spectrum disorders (FASD); pregnant women are advised to abstain completely from alcohol


Nutrients and Behaviors Are Important for a Healthy Pregnancy

• Managing chronic conditions- Diabetes, hypertension, PKU or sexually transmitted

disease can increase maternal and fetal complications if not controlled before conception

- Medications may be contraindicated during pregnancy, so prepregnancy counseling is essential


Quick Review Good nutrition and healthy lifestyle habits before

conception are important for both men and women Factors such as smoking, alcohol abuse, and obesity

decrease sperm production and function Conception is easier for women if they are at a healthy

body weight Getting plenty of folic acid, avoiding fish high in

methylmercury, limiting caffeine consumption, avoiding cigarettes, alcohol and drugs, and managing chronic conditions are essential for a healthy pregnancy

Proper nutrition and a healthy lifestyle can prevent birth defects and may reduce future health risks


Nutrition During the First Trimester Morning sickness

• Begins during the first trimester and often ends by the 20th week of pregnancy

• Cause is unknown, but estrogen is thought to play a role• Small, frequent meals, avoiding an empty stomach, high

carbohydrate foods, ginger, and salty foods combined with sour and tart beverages help manage nausea

• Vitamin B6 may reduce nausea and vomiting

• In rare cases, women experience hyperemesis gravadarum, severe vomiting which can lead to dehydration, electrolyte imbalances, weight loss and may require hospitalization


Nutrition During the First Trimester Cravings

• Researchers have not found a physiological explanation for food cravings

• Pica is the abnormal, compulsive intake of nonedible items such as laundry starch, burnt matches, clay, dirt, paint chips, and/or baking soda- More common in African-American women and

associated with low blood levels of iron


Nutrition During the First Trimester Avoiding botanicals

• Botanicals are parts of a plant believed to have medicinal or therapeutic effects

• Herbs such as blue cohosh, juniper, goldenseal and raspberry tea may cause contractions of the uterus leading to miscarrage or premature labor

Figure 17.5

Components of Weight Gain During Pregnancy


Nutrition During the First Trimester Dietary considerations

• 50% increase in needs for folate, zinc, and iron• Kilocalorie needs are not significantly increased during

the first trimester• Focus should be on intake of nutrient-dense foods • A prenatal supplement is necessary• Vegetarians and vegans should be mindful of meeting

needs for essential fatty acids and vitamin B12

• Drink milk to meet needs for calcium and vitamin D


Nutrition During the First Trimester Foodborne illness

• The immune system is weakened during pregnancy, so mother and baby are at greater risk

• Listeria monocytogenes may cause miscarriage, premature labor, low birth weight, developmental problems, or infant death

• Pregnant women should avoid raw or undercooked meats, fish, or poultry; unpasteurized milk, cheese, and juices; and raw sprouts


Quick Review Women commonly experience morning sickness and

cravings during the first trimester of pregnancy Recommended weight gain during pregnancy depends on

prepregnancy weight The needs for many nutrients are increased during pregnancy,

but most can be met with a balanced diet It is difficult to consume adequate iron from foods during

pregnancy, so a supplement is often prescribed Pregnant women should avoid excess amounts of preformed

vitamin A and D Risk of foodborne illness is increased during pregnancy, so

women should handle raw foods carefully and avoid certain raw, undercooked, or unpasteurized foods


Nutrition During the Second Trimester Consume adequate kilocalories, carbohydrate, and protein

• An additional 340 kcals daily is needed during the second trimester

• Need a minimum of 175 grams carbohydrate per day• Protein needs increase 35% to about 71 grams daily


Activity During the Second Trimester 30 minutes or more of moderate exercise on most days is

recommended Low-impact activities pose less risk for injury to mother or

baby Must take care to avoid significant increases in body core

temperature and drink plenty of fluids to avoid dehydration


Complications During the Second Trimester Potential complications: gestational diabetes and

hypertension Gestational diabetes occurs when a woman develops high

blood glucose levels during her pregnancy• May result in macrosomia, jaundice, breathing

problems, birth defects, or hypoglycemia after birth• Eating healthfully, maintaining a healthy weight, and

exercising regularly can reduce risk


Complications During the Second Trimester Pregnancy-induced hypertension includes three

categories• Gestational hypertension – occurs early in pregnancy

in women with no history of hypertension• Preeclampsia – characterized by hypertension, severe

edema and protein losses in the urine; deprives fetus of oxygen and nutrient rich blood from the placenta

• Eclampsia – can cause seizures and is a major cause of death of women during pregnancy

The only cure for preeclampsia and eclampsia is to deliver the baby


Quick Review Pregnant women need to consume an additional 340 kcals

during the second trimester Exercise can provide numerous benefits during pregnancy,

but should be limited to low-impact activities to reduce risk of injury to Mom or baby

Complications that often appear during the second trimester of pregnancy include gestational diabetes and pregnancy induced hypertension; women with these conditions should be closely monitored by a health care professional


Nutrition During the Third Trimester Eating frequent small meals and a high-fiber diet can help

with heartburn and constipation• An extra 450 kcals are needed during the third trimester• The growing baby exerts pressure on the Mom’s

intestines and stomach which can cause heartburn• Hormonal changes slow movement of food through the

GI tract which may cause constipation


Special Concerns of Younger or Older Mothers-to-Be Teenage mothers

• Still growing, therefore nutrient needs are even higher than an adult woman, yet more likely to have an unbalanced diet

• More likely to develop pregnancy-induced hypertension, iron-deficiency anemia, and deliver premature babies

Older mothers• Higher risk for complications including gestational

diabetes and pregnancy-induced hypertension• Babies are more likely to have Down syndrome or other

developmental disabilities


Breast-Feeding Lactation is the production of milk in a woman’s body

after birth• The “breast is best” when nourishing an infant

Breast-feeding provides physical, emotional, and financial benefits for mothers• Helps stimulate recovery from pregnancy including

contraction of the uterus and weight loss- May reduce risk of certain chronic diseases later in life

• Less expensive and more convenient than formula• Reduces stress and promotes bonding

Figure 17.8

The Letdown Response


Benefits of Breast-Feeding Breast-feeding provides nutritional and health benefits for

infants• Nutritional composition of breast milk changes as the

infant grows• Colostrum is lower in fat, higher in protein, vitamin A,

minerals, and antibodies• Breast milk is high in lactose, fat, B vitamins and lower

in fat-soluble vitamins, sodium, and other minerals• The American Academy of Pediatrics recommends

supplementing breast-fed babies with vitamin D drops to meet needs


Benefits of Breast-Feeding Breast-feeding protects against infections, allergies, and

chronic disease and may enhance brain development• Provides beneficial compounds including antioxidants,

hormones, enzymes, and growth factors• If continued beyond six months, may reduce risk of

childhood obesity• Breast milk is rich in docosahexaenoic acid (DHA) and

arachidonic acid (AA) which are important for development of vision and the central nervous system

• The American Dietetic Association recommends exclusive breast feeding until 6 months of age and continuation to at least one year with appropriate solid foods


Quick Review Breast-feeding provides numerous benefits to mothers and

their babies It can help mothers recover from pregnancy and may help

prevent certain chronic diseases later in life It is the least expensive and most convenient way to

nourish an infant and promotes bonding between Mom and baby

Human milk is rich in nutrients, antibodies, and other compounds that can protect against infection, allergies, and chronic disease, and may enhance cognitive development

Women are advised to breast-feed exclusively for the first six months and then breast-feed to supplement solid foods for the first year


Nutrient Needs and Habits for a Breast-Feeding Mother Should drink 13 cups of fluid per day to meet increased

fluid needs Needs additional kcals A well-balanced diet should meet nutrient needs during

lactation Substances in the mother’s body are transmitted through

breast milk; nursing Moms should avoid alcohol, drugs, tobacco, and limit caffeine

Children from families with a strong family history of foods allergies may benefit from breast-feeding


Formula Is an Alternative to Breast Milk Some women may not be able to breast-feed

• Women with AIDS, human T-cell leukemia, or active tuberculosis, who are receiving chemotherapy and/or radiation, or who use illegal drugs should not breast-feed

• Infants with galactosemia cannot metabolize lactose and should not be breast-fed


Formula Is an Alternative to Breast Milk

Figure 17.9

Formula can be a healthy alternative to breast-feeding• Developed to be as similar as possible to breast milk• Standard formula is made from cow’s milk. • Unmodified cow’s milk it too high in protein, sodium,

potassium, and too low in fat and linoleic acid for infants • To avoid nursing bottle

tooth decay and risk of ear infections, infants should not be allowed to sleep with a bottle containing sugary liquids


Quick Review If a women is unable or chooses not to breast-feed, formula

is the only healthy alternative for babies Commercially made formulas are modified from soy or

cow’s milk and designed to resemble human breast milk Cow’s milk should not be given before age 1, as it is too

high in protein and certain minerals and too low in fat Powdered and concentrated formula should be diluted and

mixed carefully to ensure babies are getting the correct calories and nutrients

To avoid tooth decay and ear infections, babies should not be put to sleep with bottles


Nutrient Needs of Infants Infants grow at an accelerated rate

• Doubles birth weight by 6 months of age and triples it by 12 months

• Length doubles by 1 year of age• Significant intellectual and social development occurs

during infancy• Adequate nutrition is needed to meet physical, social and

intellectual milestones• Failure to thrive (FTT) occurs when a child is delayed in

physical growth or size or does not gain enough weight • Growth charts are used to track physical development

Figure 17.11

Growth Chart


Quick Review Growth occurs at a dramatic rate during the first year of life Infant growth can be monitored by tracking developmental

milestones and using growth charts Nutrient needs during the first year of life are substantial,

and supplements may be needed in some circumstances


Switching to Solid Foods Solid foods are introduced around 4–6 months of age once

certain milestones are met Solid foods should be introduced gradually

• Parents should watch for signs of allergies after a new food is introduced

Food Allergy


Switching to Solid Foods Certain foods are dangerous and should be avoided

• Egg whites, cow’s milk, and peanut butter• Honey may carry Clostridium botulinum and cause

botulism in infants• Seasonings are not needed• Juice often displaces necessary nutrients and should be

limited to 100% juice and given in moderation• Infants should never be put on weight-loss diets


Quick Review An infant must be physically, physiologically, and

nutritionally ready before being introduced to solid foods Solid foods should be introduced gradually and cautiously Foods that may pose a choking hazard should be avoided

and infants should always be supervised when eating Common food allergens, honey, and herbal teas should be

avoided for the first year of life and seasonings should not be added to infant food

To keep their children healthy parents need to educate themselves about foods that are safe and appropriate for infants

Figure 17.12

Summary of Nutritional Guidelines


Putting It All Together Both the father and mother should make healthy diet and

lifestyle changes prior to pregnancy During pregnancy, nutrients, oxygen and waste products are

exchanged between mother and fetus through the placenta; harmful toxins or inadequate nutrition can cause irreversible damage to the fetus, especially during critical periods

Recommended weight gain during pregnancy depends on prepregnancy weight; caloric needs are increased during the second and third trimester of pregnancy to support weight gain; a prenatal supplement is needed for iron

Breast-feeding is the gold standard for infant nutrition; it provides physical, emotional, convenience, and financial benefits to Mom and nutritional and health benefits to baby

Infancy is characterized by rapid growth and important developmental milestones

chapter 17: life cycle nutrition: pregnancy through infancy

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