CH 12 - Fetal Development and Infant Nutrition

Fetal Development

• Lifecycle: Pregnancy to Toddler Years

• Introduction to Nutrition - Chapter 12

• Timeline:

  • 6 weeks: Placenta

  • 8 weeks

  • 3 months

  • 6 months

  • 9 months

  • Full term fetus in utero

• Umbilical cord facilitates nutrient exchange.

Key Trimester for Fetal Development

• All trimesters are equally important for fetal development.

Pregnant Nutrition

• Pregnancy is measured from the 1st day of the last menstrual period until childbirth.

• Duration: Approximately 38-42 weeks, divided into trimesters (13-14 weeks each).

• Nutrient recommendations increase to ensure proper fetal development.

First Trimester

• Nutrients are critical for:

  • Cell division

  • Tissue differentiation

  • Organ development

• Placenta Formation:

  • Facilitates oxygen, nutrient, and waste exchange via the umbilical cord.

• Vulnerability to Teratogens:

  • Embryos are more vulnerable to teratogens, which are agents that cause birth defects and miscarriages.

• Neural Tube Development:

  • The neural tube begins to develop into the brain and spinal cord.

Macronutrient Needs

• Carbohydrates: 175g/day

  • Supports Placenta and Brain Development

• Proteins: 71g/day

  • Supports tissue synthesis, blood production, and amniotic fluid development.

• Fats: 25-35% of total kcals

  • Supports brain and eye development.

• Caloric needs increase by 350-450kcals/day during the 2nd & 3rd trimester

Micronutrient Needs

• B9 (Folate): 600mcg/day

  • Supports neural tube development and cell division.

• B12: Increased blood supply.

• Choline

• Vitamin A: supports heart, lungs, kidneys, eyes, & bone development

• Iodine: supports brain development

• Calcium & Vitamin D: support bone development

• Iron: hemoglobin synthesis

  • Fetus stores iron for the first 6 months after birth

Pre-Pregnancy BMI

• Pre-pregnancy BMI determines the amount of weight gain needed.

• Low BMI (<18.5): Increases the risk of premature birth and low-birth-weight.

• High BMI (>30): Increases the risk for gestational diabetes, pre-eclampsia, cesarean delivery, macrosomia (large baby), & childhood obesity.

Pregnancy Weight Gain

• 1st trimester: ~3-5lbs total

• 2nd & 3rd trimesters: ~1lb/week.

• Appropriate weight gain supports fetal development and prepares for breastfeeding.

• More weight gain is advised if there is more than one fetus

Low Birth-Weight

• Low birth-weight babies have increased risk of infections, learning disabilities, impaired growth, & death within the 1st year.

  • Low: 3.3-5.5lbs

  • Very low: 2.2-3.3lbs

  • Extremely low: <2.2lbs

Physical Activity Recommendations

• 150min/week of moderate-intensity aerobic activity is recommended.

• Physical activity is generally safe, but should cease if complications arise.

• After the 1st trimester, avoid activities that are high impact, high fall risk, or involve prolonged back laying.

• Reduces risk of gestational diabetes, pre-eclampsia, premature birth, macrosomia, lower back pain, & shortens labor.

Substances to Avoid

• Alcohol: Can cause fetal alcohol spectrum disorders (FASD).

  • Can slow fetal growth, damage the brain, & result in miscarriage.

  • Effects are most severe in the 1st trimester.

• Smoking (tobacco and other substances):

  • Can impair oxygen & nutrient supply.

• Many drugs can pass through the placenta

Foods to Avoid/Reduce

• Foods contaminated with heavy metals should be avoided.

• 8-12 oz/week of seafood from low mercury choices recommended.

• Caffeine may increase the risk of miscarriage and low-birth weight.

  • Recommended to limit to <200mg/day (12oz coffee).

Foodborne Illnesses

• Pregnant people are more susceptible to foodborne illnesses.

• ~33% of congenital listeriosis result in permanent disability or death.

• Follow food safety standards and avoid high risk foods

Pregnancy Complications

• Nausea: Typically occurs in 1st trimester. Can lead to hyperemesis gravidarum, which is severe nausea that requires hospitalization.

• Gestational Diabetes: High blood glucose and insulin resistance. Can increase, macrosomia & type 2 diabetes risk, & require c-section

• Gestational Hypertension: High blood pressure that can impair nutrient and oxygen delivery. Can lead to pre-eclampsia

Infant Development

• Important growth measurements include length, head circumference, & weight

• Growth charts are used to compare with other infants in the U.S.

• Poor weight or length gain (<5th percentile) may indicate failure-to-thrive (FTT).

  • May be caused by inadequate or inappropriate food and/or ongoing medical condition

Macronutrient Needs for Infants

• 40-50kcals/lb/day

• Extrusion Reflex: <6mo olds will push solid food out

• <6mo: breast milk is preferred. >6mo: solid food may be added

• Carbs: 40-50% of total kcals

  • Supports brain development

• Proteins:

  • 0-6mo: 9g/day

  • 7-12mo: 11g/day
    *Supports growth & immune system

• Fats:

  • 0-6mo: 60g/day

  • 7-12mo: 95g/day

  • Supports growth & brain development

  • <20% of kcals due to immature kidneys

Infant Micronutrient Needs

• Most nutrients can be met with breast milk except:

  • Vitamin D – calcium absorption & bone health

    • Supplements recommended if breastfeeding

    • Formula is typically fortified with vitamin D

  • Iron – support growth and blood production

    • After 4-6 months, iron-rich foods or oral supplements should be provided

    • Some formula are fortified with iron

Infant Fluid Needs

• Infants require $1.5 mL/kcal$ of fluid.

• High risk for dehydration due to their surface area & reduced capacity for sweating.

• Breast milk or formula should be the main source because their immature kidneys can’t handle large amounts of water

Breastmilk

• Alveolar cells in the mammary glands produce, store, & secrete milk

• Lactation – production & secretion of breastmilk

• Prolactin – stimulates milk production & helps regulate its secretion

• Oxytocin – facilitates release when infant suckles (milk ejection reflex)

• Progesterone – inhibits milk secretion

Breastfeeding Nutrient Needs

• Energy needed to support breastfeeding comes from increased intake & stored fat.

  • 700-800 kcal/day

• Most micronutrient RDAs increase

• Avoid harmful substances

• Alcohol is permitted, but must wait until it has cleared from milk (2-3hrs for 1 drink depending on body weight)

Components of Breast Milk

• Breast milk contains antibodies, enzymes, white blood cells, cholesterol, & several micronutrients

• Easier for infants to digest due to higher whey than casein composition

• 3 types that contain specific nutrients to support growth & development

  • Colostrum

  • Transitional Milk

  • Mature Milk

Breast Milk Types

• Colostrum – initial milk produced after birth

  • Less volume, but rich in protein, fat-soluble vitamins, minerals, antibodies, & growth factors

• Transitional milk – produced ~2-4 days after birth

  • More calories, fat, lactose, & water-soluble vitamins

• Mature Milk – produced ~2 weeks after birth

  • ~90% water; ~10% macro- & micronutrients

  • Foremilk – initial release; more water & water- soluble nutrients

  • Hind-milk – after foremilk; more fat & fat-soluble nutrients

Barriers to Breastfeeding

• Engorgement, mastitis, (inflammation of breast tissue), clogged duct (makes it painful/uncomfortable) and lack of accommodations to breastfeed or express milk in public

• Improper latching can result in inadequate intake, which slows growth & development

• International Board-Certified Lactation Consultants teach proper breastfeeding technique

Formula Feeding

• Powder – requires mixing with water ($)

• Concentrates – liquids that must be diluted with water ($)</p></li><li><p><mark data-color="purple" style="background-color: purple; color: inherit">Ready-to-use</mark> – liquids that can be poured directly into bottles ($$)

• Must follow package instructions to avoid over-dilution/concentration

• Also make sure to follow food safety bc they’re more susceptible to infections and food borne illnesses

Breastfeeding or Formula?

• Breastfeeding has several advantages over formula:

  • More cost-effective & not affected by recalls or supply chain shortages

  • Easier to digest due to higher whey to casein ratio

  • It is sterile & does not have to be mixed, heated, or prepared

  • More sustainable due to less plastic & other waste

  • Lower risk for asthma, allergies, sudden infant death syndrome (SIDS), diarrhea, GI issues, as well as respiratory & ear infections

• Formula should be used if consuming harmful substances or there is transmissible disease risk

  • If you still have to breastfeed, it is recommended to take antiretrovirals while breastfeeding to mitigate risk of transmission

Feeding Problems During Infancy

• Tooth decay – excess juice or prolonged bottle-feeding increases risk

• Unsafe foods – honey & corn syrup (botulism risk), grapes, corn, nuts, or meat chunks (choking hazard)

• GERD – should burp more often, small & more frequent meals, feeding upright, & delaying play time after meals (stomach acid coming up)

• Food allergies – breastfeeding & waiting at least 6 months to introduce solid foods reduces allergenicity

  • Should introduce food slowly so that you can better identify which foods cause an allergy

  • Soy or hypoallergenic formula for milk allergy

Toddler (1-3) Nutrient Needs

• Caloric needs are higher than infants due to size and activity level

  • More complex carbs, limit fruit juice to 4oz/day (American Academy of Pediatrics)

• Vitamin D – $15mcg/day$; fortified foods or supplements

• Calcium – $700 mg/day$; dairy or fortified foods

• Iron – $7mg/day$; lean meats, fish, poultry, eggs, & whole-grain bread/cereal

  • Although it is the most deficient nutrient in the world, it is also the most common cause of poison in children under 6

• Carbs - will be around the same of 45-65% of total calories as we continue to age

• Protein - As kidneys develop, the body will be able to handle more protein, so recommended protein levels will increase as we age

  • Increased to 5-20% of total calories from infancy

• Fats - fat recommendation will decrease as we age

  • Decreased to 30-40% of total calories from infancy