Life Cycle Nutrition: Lactation & Breastfeeding

lactation

process of milk production and secretion in the mammary glands

lactogenesis

human milk production

breastfeeding

delivery of milk to the infant from the breast

Lactogenesis I

First few days after birth; colostrum

Lactogenesis II

2 - 5 days after birth; milk “comes in;” transitional milk

Lactogenesis III

~10 days after birth; mature milk

Human Milk Substitutes

After WWII, these became available and made formula feeding infants popular.

States with Highest Breastfeeding Rates

Vermont, Idaho, Minnesota, Colorado

States with Lowest Breastfeeding Rates

Mississippi, Florida, West Virginia, Alabama

Baby-Friendly Hospital

Hospital program that has optimal care of infant feeding (lactation) and mother-baby bonding. Optional certification, but many hospitals are being certified.

10 Steps to Successful Breastfeeding (Hospital)

1. Written breastfeeding policy that is communicated to all health care staff.

2. Train all health care staff w/ skills for this policy.

3. Inform all pregnant women about breastfeeding benefits.

4. Help mothers initiate breastfeeding w/i 1hr birth

5. Show mothers how to breastfeed and maintain lactation (even if separated from infants)

6. No food or drink for infants other than breast-milk (unless medically indicated)

7. Practice rooming in (mother and infant stay in same room)

8. Encourage breastfeeding on demand.

9. No pacifiers or artificial nipple to breastfeeding infants.

10. Have breastfeeding support groups and refer mothers to them on discharge.

American Academy of Pediatric Recommendations

Infants be exclusively breastfed for the first 6 months; continued breastfeeding and food supplementing for 1 year<.

Breast Feeding Advantages (in Developing Countries)

• Less diarrhea related illnesses

• Less serious illnesses

• Sanitation

Infant Advantages of Breast Feeding

• Nutrients are easier to absorb and digest

• Protein content is lower (easier on infant kidneys)

• High in whey protein (soft, easily digestible)

• Generous amounts of lipids (omega-3’s are high)

• Isotonic with maternal plasma (same solution concentration)

• Immunological benefits (IgA)

• Minerals very bioavailable

• Reduced mortality rates

• Less illness, infections, allergies

• Analgesic effects

• Helps development jaw, tongue, teeth (sucking at the breast)

• Bonding with mother

• Long term benefits (lower risk of celiac disease, IBS, and leukemia, reduce risk of allergies and asthmatic disease)

• May enhance nervous system and brain development

• Bacteriologically safe

• Antibodies to mature GI tract

• Leaner at 1yr of age

Benefits of Breastfeeding

• Increased oxytocin stim. uterus to return to pre-pregnancy state

• Delays menses (replenish iron stores)

• Delay in monthly ovulation—longer intervals between pregnancies.

• Increased self-confidence and bonding with infant.

Maternal Benefits of Breastfeeding

• Safe, convenient, economical, always fresh

• Promotes maternal-infant bonding

• Builds maternal self-condience

• More economical than formula feeding

• Future health benefits

Neonatal Galactorrhea

~5% infants produce “witches milk” 2-3 days post-delivery—from contraction of mother’s hormones

Adolescence

Breast develops to full size (~200g/breast)

Pregnancy

~400-600g/breast

Lactation

~600-800g/breast

Adolescent Breast Development

• Mammary glands elongate and proliferate

• Duct system, areola, nipple grow

Mammary Glands

“The breast;” consists of alveoli, duct system, areola

Alveoli

Milk is produced here; “function unit of the breast.” Consists of clusters of secretory cells and myoepithelial cells.

Areola

Pigmented area surrounding the nipple that contains sebaceous glands

Myoepithelial Cells

line the alveoli and contract to cause milk secretion into the ducts.

Lactiferous Ducts

Path from milk producing cells in alveoli to storage and release areas in the breast.

Lactiferous Sinuses

milk is stored here (behind the nipple)

Sebaceous Glands

Lubricate the nipple and have muscle fibers that stiffen the nipple to help the baby suck.

Montgomery’s Tubercles

raised areas around the nipple that secrete lubricant.

Path of Milk Delivery

Milk produced in alveoli —> travels down small ducts —> travels into larger ducts —> stored in lactiferous sinuses —> infant latches on and milk is delivered

Prolactin

Hormone that promotes milk production. Release is stimulated by infant suckling.

Oxytocin

Causes milk to eject from glands. Stimulated by infant suckling.

Breast Changes During Pregnancy

1st Trimester: ducts proliferate to create maximum number of cells.

2nd Trimester: ducts group together to form large lobules.

3rd Trimester: cells dilate

Antepartum Period

time right before birth

Parturition

Childbirth

Milk Production (Lactogenesis)

1. Milk synthesis in alveoli & passage into ducts

2. Milk ejects from ducts into storage area (lactiferous sinuses)

3. Milk ejected from sinuses and is dispensed to infant

Galactopoiesis

Maintenance of established milk production.

Prolactin Control Center

Anterior pituitary

Oxytocin Control Center

Posterior pituitary

Prolactin Inhibiting Factor Control Center

Hypothalamus

Prolactin Inhibiting Factor (PIH)

Prevents milk production in last 3 months of pregnancy; controls and regulates production of milk

Galactorrhea

Spontaneous secretion of milk

Milk Release Process

1. Infant “latches on” by rooting reflex

2. Oxytocin causes myoepithelial cells to eject milk into ducts and milk is sent to sinuses.

3. Milk is now available to the infant.

Milk Production Range

450-1200mL/day; 600mL (1st month), 750-800mL (4-5 months)

Colostrum

produced in lactogenesis I (1-3 days after birth); yellow in color; high in IgA antibodies & lactoferrin; facilitates meconium (first infant stool); ~17kcals/oz, higher in protein than other milks, lower in carbohydrate and fat

Transitional Milk

produced in lactogenesis II (day 3-6)

Mature Milk

produce in lactogenesis III; ~19-22kcal/oz, thin, watery, blue-ish in color; fat composition varies more than other nutrients; isotonic with mother’s plasma

Preterm Milk

produced by mothers of preterm infants; higher in protein, lower in volume than mature milk

Foremilk

milk released first during feeding; higher in nutrients, lower in fat.

Hindmilk

milk released at the end of feeding; higher in fat (satiates the infant)

Human Milk Composition

39% CHO, 6% PRO, 55% Fat; water

CHO in Breast Milk

lactose (major)—assists w/ absorption of Ca; oligosaccharides stimulate growth of bifidus factor (inhibits e. coli growth in infant’s gut) & help prevent infection of infant’s gut.

PRO in Breast Milk

lower amount than cow’s milk, higher in whey (vs. cow’s milk—higher in casein); overall lower renal solute load (content of mother’s diet doesn’t effect milk’s content)

Lipids in Breast Milk

fat is infants major energy source; DOES reflect mother’s diet (fatty acid profile vs. content); DHA (essential for brain, CNS, and retinal development); cholesterol (higher than formula)

Vitamin A in Breast Milk

meets the infant’s needs, colostrum has 2x concentration

Vitamin D in Breast Milk

content reflects mothers exposure and consumption; supplementation may be needed if mother’s exposure is low to lower risk of rickets; 400IU (1st 2mths), 600IU 1yr<

Vitamin E in Breast Milk

premature infants need more of due to higher risk of erythrocyte hemolysis.

Vitamin K in Infant

single dose is given at birth

Water Soluble Vitamins in Breast Milk

more likely reflects maternal intake; supplements show up in breast milk; (B12 & folate less likely to reflect maternal intake)

Minerals in Breast Milk

much lower than formula due to high bioavailability; less Na; only one that reflects maternal intake is fluoride

Iron in Breast Milk

high bioavailability—49% vs 10% in formula; breast fed less likely to suffer iron deficiency anemia

Infant and Water Intake

breast milk has enough water for infant; breast milk is isotonic with maternal plasma

Bifidus Factor

a CHO that stimulates growth of Lactobacillus bifidus and inhibits invasive organism growth in infants’ GI tract

Immunoglobulins in Human Milk

IgA, IgG, IgD, IgM, & IgE all present in breast milk; IgA major one (all prevent against harmful bacteria)

Lysozyme

antimicrobial enzyme; 300x more than in cow’s milk

Lactoferrin

iron binding protein; inhibits growth of staphylococci & e. coli by binding iron that those bacteria need to grow

Lactoperioxidase

kills streptococcus bacteria & enteric (sm. intestine) bacteria

Macrophages

renders pathogenic bacteria susceptible to phagocytosis

Dietary Recommendations During Lactation

diet can meet the needs of infant and mother during lactation; supplementation is not usually needed (there are exceptions)

Metabolic Changes in Mother During Lactation

in early lactation, pregnancy fat stores are used for milk production (100-150kcal/day); milk production will decrease is mother consumes <1500kcal/day

Lactation Calorie DRI

1st 6 mo.: +330kcals/day; 2nd 6 mo.: +400kcals/day

Protein Intake During Lactation

1.3g/kg/day; maternal nutrition has little effect on protein profile in breast milk—it stays consistent unless there’s severe malnutrition

Emile is 5’2” and weighs 135lbs, she consumed 2300kcals/day prior to pregnancy and is now breastfeeding her son of 8 months. How many calories and grams of protein does she need each day?

2300 + 400 (for 2nd 6mo breastfeeding) = 2700kcals/day; 135/2.2 = 61.4kg—61.4 × 1.3 = 79.8g/PRO/day

CHO Intake During Lactation

~50-60% daily kcals; 160-210g/day recommended to prevent ketosis and maintain normal blood glucose levels; complex CHO and high fiber!

Fat Intake During Lactation

fatty acid profile consumption can be reflected in breast milk; 15-30% daily kcals; omega 3 & 6 very important! (Cholesterol is not reflected in breast milk)

Calcium Intake During Lactation

amount in breast milk is not determined by diet; calcium mother loses to milk is ~240mg/day—reccomendations: <18: 1300mg/day, >18: 1000mg/day

Calcium Metabolism During Lactation

calcium absorption increased and excretion decreased during lactation; prolonged lactation with low Ca may lead to osteoporosis; lactation decreases risk of osteoporosis and fractures in future.

Iron Intake During Pregnancy

less lost because of lack of menses; 9-10mg/day recommended

Zinc Intake During Pregnancy

only ~20% absorbed; 12-13mg/day recommended; from meat, fish, poultry, fortified cereals, legumes, and grains

Vitamin D Intake During Pregnancy

amount in breast milk is reflected by mother’s intake and exposure! AI: 600IU/day; mother must supplement if lactose intolerant; breast fed infants should receive a supplement

Fluid Intake During Pregnancy

vital, important component of breast milk; milk volume is not determined by intake; 3-4L/day; drinking with was nursing session

Breast Milk Contaminant Considerations

M/P ratio; infants ability to absorb, metabolize and excrete drug; dose and duration of use; infants age, health and feeding pattern

Drug Intake Recommendations while Breast Feeding

• avoid long acting drugs

• take medication right after nursing

• observe your infant for negative reactions

• consult with MD about drug options that impact breast milk the least

American Academy of Pediatrics

sets the standards and guidelines for infant intake, formula, etc. for practitioners to follow

Herbal Use While Breastfeeding

limited research on safety; galactagogues (increase milk production); herbs should be viewed as drugs—their pharmacological and toxicological potential must be evaluated

Marijuana (THC) Use During Lactation

does pass into breast milk; concentration in milk is 8x that of mother’s blood level—AAP designates “drug of abuse”

Alcohol (EtOH) Use During Lactation

does pass into breast milk; matches level of maternal plasma; peaks: 30-60min (empty stomach, 60-90min (with meal)—limit amount and timing of consumption

HIV and Lactation

can be passed from mother to infant through breast feeding; transmission rates 5-20% (short term) 35-40% (long term)—U.S. rec. D/C breastfeeding, WHO rec. only for first 6 months if formula is not available

Environmental Exposures in Breast Milk

mother’s exposed to heavy metals, pollutants, and volatile solvents daily will likely have present in their breast milk; long-term effects unknown

Nicotine Use While Lactating

does pass into breast milk; decreases milk volume/inhibits let down; can affect infants ability to breast feed

Caffeine Use While Lactating

1% maternal dose enters breast milk; infants cannot metabolize until 3-4mo.; large doses = “coffee nerves”—limit intake and observe infant

Contraception During Lactation

prolactin produced through infant suckling inhibits estrogen, FSH, and LH—inhibiting ovulation; breast feeding is not a rec. form of birth control.

Prolonged Postpartum Anovulation

frequent feedings = ↑ level prolactin = ↓ levels of FSH, estrogen, and LH —> no ovulation —> infant begins eating solids, feedings less frequent —> ↓ prolactin levels, ↑ levels FSH, estrogen, and LH —> ovulation and possible pregnancy

Oral Contraceptive and Lactation

use in early lactation can inhibit milk production from ↑ estrogen; rec. progesterone only; 6wks+, can use combination if things are going well

Weight Loss Post-Pregnancy

safe to decrease by 500kcals/day once breastfeeding is established; >1500kcals/day = ↓ milk volume

Vegan Diet While Breastfeeding

adequate and safe if well planned; multivitamin (B12, Ca, Zn) rec.—monitor protein intake

Proper Storage/Handling of Breast Milk

• store small amounts to limit waste

• label with date if freezing

• never mix fresh and frozen

• never reuse after feeding

• no microwaving/refreezing

• clean area/hands

Temperatures for Storage of Breast Milk

• countertop/table (room temp.): 6-8hrs

• fridge (39F, 4C): 5 days

• freezer compartment of fridge (5F, -15C): 2 wks

• freezer chest (-4F, -20C): 6-12mo.

Milk Banking

“first alternative” for mother’s who cannot breastfeed; very expensive; donors must go through a screening process

Human Milk Banking Association of North America (HMBANA)

regulates national milk banking and screening, pasteurizes and tests breast milk before dispersing to hospitals; must obtain rx from PCP to receive milk