Life Cycle Nutrition: Life Cycle Nutrition: Pregnancy, Lactation, Pregnancy, Lactation, & Infancy& Infancy

Chapter 14

PregnancyPregnancy

Nutrition may affect fertility Preparation before pregnancy

Achieve and maintain healthy body weight Choose an adequate and balanced diet Be physically active Receive regular medical care Manage chronic conditions Avoid harmful influences

Stages of Embryonic and Stages of Embryonic and Fetal DevelopmentFetal Development

The Placenta and The Placenta and Associated StructuresAssociated Structures

Growth and Development Growth and Development During PregnancyDuring Pregnancy

Critical periods Times of intense development Many happen in the first several weeks!

Mother’s nutritional status crucial beginning at moment of conception

About 1/2 of pregnancies are unplanned Adverse influences on organ and tissue

development Alcohol, tobacco, and other substance use Imbalances of key nutrients

Critical Periods of Critical Periods of DevelopmentDevelopment

Folate StatusFolate Status Low: neural tube defects

AnacephalyBrain either missing or fails to develop

Spina bifida Incomplete closure of spinal cord & its

bony encasement

400 micrograms/day of folic acid recommended, plus food sources

Neural tube develops in first 6 weeks

Neural Tube Neural Tube DevelopmentDevelopment

Spina BifidaSpina Bifida

Other Key NutrientsOther Key Nutrients Pre-formed vitamin A

– Too much is teratogenic– UL: 3,000 mcg (10,000 IU)/day– Accutane and Retin-A: potent teratogens– Beta-carotene is safe!

Iron– Good status is important prior to conception– If low, mother can experience anemia during pregnancy

Omega-3 fatty acids: DHA/EPA– Crucial for neurological development– Sources: seafood, grass-fed beef, omega-3 eggs– Watch out for mercury

• Limit: albacore tuna• Avoid: tilefish, shark, swordfish, king mackerel

Maternal WeightMaternal Weight Weight and health prior to conception

Influences fetal growth and pregnancy outcomes Underweight

Increased rates of preterm births (before 37 weeks), low birth weight, and infant deaths

Increases child’s risk for heart disease or diabetes

Overweight & obesity Medical complications: HTN, gestational diabetes,

preeclampsia, prolonged labor, difficulty breastfeeding

Risks for infant

Recommended Weight Recommended Weight GainsGains

Components of Weight Components of Weight GainGain

Maternal WeightMaternal Weight Weight loss after pregnancy: takes time!

Some lost in childbirth (~10 pounds) Weeks after delivery: fluid volume returns to

normal (about another 5 pounds) Return to pre-pregnancy weight not typical during this

time Many retain a couple of pounds with each pregnancy

(as body fat)

Retention of seven or more pounds Diabetes and hypertension Chronic diseases later in life

Breastfeeding helps significantly

Exercise During Exercise During PregnancyPregnancy

Can continue exercise throughout pregnancy Adjust duration and intensity

Benefits: Prevention/management of gestational DM Easier labor Fewer discomforts during pregnancy Reduced stress Maintaining fitness can help with post-pregnancy

weight loss

“Low-impact” activities Avoid excessively high internal body temperature

Energy & Nutrient Energy & Nutrient Needs: Pregnancy and Needs: Pregnancy and LactationLactation Needs tend to be higher than any other time in life Increased BMR Depositing and maintenance of new fetal and

maternal tissues Energy: 15 to 20% more energy than before

pregnancy Even greater increase in micronutrient needs

Choose nutrient-dense foods Differences between pregnancy and lactation

requirements Many needs even greater in lactation

MacronutrientsMacronutrients Carbohydrate

Ample carbohydrate is necessary; fuels fetal brain during pregnancy

175 g or more/day (no less than 135 g/d) Protein

RDA – additional 25 grams per day (or adjust to 1.1 g/kg)Supplements are discouraged

Essential fatty acids Omega-3 and omega-6 fatty acids for brain

material

Micronutrients Blood production, cell and

tissue growth in mother and fetus Needs for synthesis of

DNA and new cells Folate Vitamin B12

Vitamin B6

Iron Zinc

Bone and connective tissue Calcium Vitamin D Vitamin C

Increased energy utilization B vitamins

Some recommendations remain the same; others increase

Prenatal vitamin usually recommended Does not take the place

of a nutrient-rich diet! Does not meet all needs

Water

Water needs increase – Blood volume– Production of other fluids– Fluids for fetus

6-9 liters of water accumulated during pregnancy!

Increase intake from 2.7 liters to 3 liters/day

Needs During LactationNeeds During Lactation Energy needs and exercise

Uses almost 500 extra kcalories per day Need 330-400 from food, the rest from fat stores Minimum: 1800 kcal/day to meet all needs

Exercise is compatible with breastfeeding Energy nutrients

Recommendations increase above pregnancy recommendations for carbohydrates and fibers

Micronutrients: relative to pregnancy, several increased recommendations for vitamins and minerals, some decreased

Water 1 additional liter of water per day to prevent dehydration

Bottle Feeding & Formula Weak/small infants may have difficulty suckling

– Bottles provide more forceful flow Drugs and communicable diseases

– Avoiding risk to infant health outweighs benefits of breast milk

Infant formula– Not milk or milk substitutes!!!– Most based on cow’s milk, some soy or elemental– Most fortified with iron– Some fortified with EFA--more expensive

Baby bottle tooth decay– Usually due to allowing baby to take bottle to bed

Nutritional Needs of Infancy Growth more rapid than any other time of life Kcal needs per kg of body weight are high

~100 kcal/kg/day vs. 30 in adults Macronutrient proportions differ from adult

needs– Small stomach– More fat needed to increase energy density– Type of fat also important to support nervous

system development• DHA (n-3) and AA (n-6)• Both contained in breast milk• Addition of these is not required in formula in US

Macronutrient Distribution: Infant vs. Adult

Assessing

Infant Growth