Life Cycle: Maternal and Infant Nutrition BIOL 103, Chapter 12.

Life Cycle: Maternal and Infant Nutrition

BIOL 103, Chapter 12

Today’s Topic

• Pregnancy• Lactation• Resources for Pregnant and Lactating Women

and their Children• Infancy

Pregnancy

• (Pg. 500)“Energy and nutrient needs both increase, but needs for calories increases by a smaller percentage than for most vitamins and minerals. As a result, food choices during pregnancy must be nutrient-dense.”

Pregnancy

• Nutrition before conception– Goals of preconception care is to provide:

1. Screening for risk2. Health promotion and education3. Intervention as needed

– Weight• Maintain a healthy weight• Low or high weight increases risk for poor outcome

– If low – If too high

• Not a good time to “diet”

Nutrition Before Conception• Vitamins (Problem Set 12, Q 1a and 1b)

– 400-800 micrograms of synthetic folic acid/day• Why?

– Avoid high doses of vitamin A (retinol)• Why?

• Substance use– Eliminate alcohol, tobacco, drugs, prior to pregnancy

Physiology of Pregnancy

• Trimesters: 3 time periods of pregnancy, each lasting ~13-14 weeks

• Stages of human fetal growth1. Blastogenic stage: Weeks 0-2

• Cells differentiate into fetus and placenta

2. Embryonic stage: Weeks 2-8• Development of organ systems• Critical period of development

3. Fetal stage: Weeks 9 to delivery• Growth

Physiology of Pregnancy

• Maternal changes:– Growth of maternal

tissues weight gain and lactation.

– Increase in maternal blood volume

– Slower GI motility increases nutrient absorption.

Maternal Weight Gain

• Recommendations depend on BMI – Table 12.3: Guidelines for weight gain during

pregnancy.• Underweight Gain 28-40 pounds• Normal weight Gain 25-35 pounds• Obese 11-20 pounds

– Higher recommended gain for underweight women, teens, and multiple fetuses

– Lower recommended gain for overweight and obese women

Maternal Weight Gain• Weight gain occurs mostly during 2nd and 3rd trimester.• 40% of weight gain fetus, placenta, amniotic fluid• 60% of weight gain maternal tissues (adipose stores, breast/uterine

growth, expanded blood and ECF)

Energy and Nutrition During Pregnancy

• Energy– REE increases to support increased workload on

mother’s heart and lungs, and energy requirements of fetus/placenta.

– Weight gain

• Nutrients to support pregnancy– Well-balanced diet– Often, pregnant women have difficulty consuming

enough folic acid and iron

Energy and Nutrition During Pregnancy

• Macronutrients– Moderate-protein, low-fat, and high carbohydrate

• Protein– Synthesis of new maternal, placental, and fetal tissues– Additional 25 gram/day over non-pregnancy needs

• Fat – Fuel for mother and development of placenta– Stored fat supports breastfeeding

• Carbohydrates– Main source of extra calories– Complex carbohydrates– Fiber-rich

Energy and Nutrition During Pregnancy

• Micronutrients– Increased need for overall calories– Increased needs for most vitamins and

minerals• Support growth and development

– Q: How are B vitamins used during pregnancy?

Food Choices for Pregnant Women

• Follow the USDA’s Daily Food Plan for Moms– Variety– Additional servings of grain, vegetable, fruit, and

low-fat milk

• Supplement with prenatal formula– Herbal supplements?– Multi-vitamin supplements?

Food Choices for Pregnant Women

• Foods to avoid1. Alcohol2. Large fish

• Why?

3. Less than 300 milligrams of caffeine per day

Substance Use and Pregnancy Outcome

1. Tobacco– Risk for miscarriage, stillbirth, preterm

delivery, and low birth weight2. Alcohol

– Risk for fetal alcohol syndrome

3. Drugs– Risks for miscarriage, preterm delivery, low

birth weight, birth defects, and infant addiction

Strategies to Avoid GI Distress:• Slowed GI movement nausea, heartburn and constipation• Smaller/frequent meals, drinking liquids between meals, fiber and

fluids are recommended

Special Situations During Pregnancy

• Food cravings and aversions– Food cravings/aversions are rarely based on a

nutrient deficiency or a physiological condition.– Pica

• Hypertension– Preeclampsia:

• Can progress to eclampsia (seizures)

Special Situations During Pregnancy

• Diabetes– Adjust diet and insulin as needed

• Gestational diabetes: – Hormones of pregnancy tend to counteract

insulin• Often controlled through diet• May require insulin

Special Situations During Pregnancy

• HIV/AIDS– Medical treatment to reduce risk of

transmission– >90% of childhood HIV infections are from

mother-to-child transmission – Many times, women with HIV or AIDS are

likely to have multiple nutrition problems:

Special Situations During Pregnancy

• Adolescence– Extra demands for growth and development– Risk for preeclampsia, anemia, premature

birth, low-birth-weight babies, infant mortality, and sexual transmitted disease

– Pre-pregnancy eating patterns a concern– Weight gain toward upper limit recommended– Need for supplements

Lactation

• Breastfeeding trends

• Healthy People 2020 goals– To increase the proportion of newborns who

are initially breastfed to almost 82%– Current stats:

• 74% of infants breastfed initially• 44% of infants still breastfed at 6 months

Physiology of Lactation

• Changes during adolescence and pregnancy– Increased breast tissue – Maturation of structure

ducts/glands and secretory cells are formed

• After delivery– Milk production and

secretion• Colostrum

Physiology of Lactation

• Hormonal controls stimulated by infant suckling:– Prolactin– Oxytocin

• “Let-down” reflex

Summary of Lactation Physiology

•Infant suckling pituitary gland release prolactin milk tissue production

•Infant suckling pituitary gland release oxytocin release milk

•Thus, giving water or infant formula to the baby reduces the time spent nursing at the breast milk production declines

Nutrition for Breastfeeding

• Energy and protein– Higher needs than during pregnancy– Well-nourished pregnant women will lose

weight slowly 1 ¾ lbs/month after ~6 months. • Vitamins and minerals

– Most are higher or same as during pregnancy– Iron and folate needs are lower

• Water– AI for total water = 3.8 liters/day

Nutrition for Breastfeeding

• Food choices– USDA’s Daily Food Plan for Moms– ~2,200–2,800 Kcal/day– Choose foods high in vitamins and minerals

and low in added sugar and solid fats• Supplementation is generally not

necessary, unless…– B12 for vegans– Vitamin D for women with irregular sun

exposure• Practices to avoid during lactation

– Smoking, Alcohol, Drugs

Benefits of Breastfeeding (PS12, Q3a)

• Benefits for infants1. Optimal nutrition2. Builds stronger immune system: protects

infant from infections and illness including diarrhea, ear infections, pneumonia, and asthma

3. Convenience

Benefits of Breastfeeding (PS12, Q3b)

• Benefits for mother1. Enhanced recovery of uterus size2. Help women return to pre-pregnancy weight

faster3. Convenience

• Contraindications to breastfeeding– Infant or maternal disease (HIV)– Damaged breast ducts– Drug use

Resources for Pregnant and Lactating Women and their Children

• Promote health of pregnant and breastfeeding women and their children

• Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)– Service of USDA– Provides food assistance– Provides nutrition education– Provides referrals

Infancy

• Infancy: 0 -1 years old

• Growth is the best marker of nutritional status

– Evaluated using growth charts1.Weight gain

2.Length gain (not height B/C infants can’t stand)

3.Head circumference measures brain growth and development

Energy and Nutrient Needs During Infancy

• Requirements based on composition of breast milk– Energy and Protein

• Highest needs of any life stage• 2x adult’s needs

– Carbohydrate and fat• Both are major energy source• Carbohydrates as simple sugars

– Water?

Energy and Nutrient Needs During Infancy

• Key vitamins and minerals– Vitamin D– Vitamin K– Vitamin B12

• Folate metabolism and cell division

– Iron: if formula fed, need iron-fortified formula– Fluoride: at 6 months

Energy and Nutrition needs during Infancy

• Newborn Breastfeeding – Recommended as the ideal method of feeding

infants to achieve optimal growth and development.

– AAP recommends that NO supplements of formula or water be given to breastfed neonates unless medically indicated

Energy and Nutrient Needs during Infancy

• Alternative feeding: Infant Formula1. Standard infant formula

• Cow’s milk base• “imperfect copy” of breastmilk

2. Soy-based formula• Soy protein base• Switched to soy-based if formula-fed

infants are having feeding problems

Energy and Nutrient Needs during Infancy

– Special formula for formula-fed infants who are:

• Allergic to milk/soy• Premature babies• Have rare defects in

metabolic pathway

• Use medium-chain triglycerides as the fat source

Energy and Nutrient Needs during Infancy

• How much is enough?– Guidelines for feeding infant

1. 6 or more wet diapers per day

2. 3 or more stools per day

3. Regain to birth weight within the first week

– Best indicators that baby has enough to eat?

Introduction to Solid Foods

• Readiness for complimentary foods at ~6 months in addition to breast milk/infant formula

• Infants show:1. Physiological readiness:

• Digestive enzymes• Ability to maintain hydration• Depletion of iron stores

2. Developmental readiness:• Lack of extrusion reflex • Head and body control

The Start Healthy Feeding Guidelines• Feeding schedule for the first two years

Feeding Problems during Infancy

1. Colic– Crying and distress, perhaps from abdominal

cramping– No clear effective treatment

2. Early childhood dental caries

3. Iron-deficiency anemia– For older infants who do not eat enough iron-

rich foods.

Feeding Problems during Infancy

4. Gastroesophageal reflux – ~3% of newborns, usually male– Usually disappears within 12–18 months

5. Diarrhea

6. Failure to thrive (FTT)– Poor growth in absence of disease– Can be due to shortage or improper

preparation of appropriate foods