Lactation (2) Flashcards
1
Q
Lactation Ability
A
Determined by…
- Intact mammary tissue and development of milk producing cells (alveoli) ducts and nipples
- Initiation and maintenance of milk secretion
- Ejection of milk from alveoli to nipple
99% success at initiation of lactation when attempted
2
Q
Lactogenesis - Stage 1
A
- Last trimester and 1st few post-partum days
- Milk begins to form
- Lactose and protein content increases
- Suckling not necessary to initiate production
3
Q
Lactogenesis - Stage 2
A
- 2-5 Days → 2 weeks post-partum
- Onset of copious milk secretion
- When milk “comes in”
4
Q
Lactogenesis - Stage 3
A
- 10-14 days post-partum
- Milk composition becomes stable
- Full lactation
5
Q
Prolactin in Lactogenesis
A
- Stimulates milk production
- Secretion stimulated by sucking
- Inhibits ovulation
6
Q
Oxytocin in Lactogenesis
A
- Secretion stimulated by sucking
- stimulates milk ejection, letdown
- Promotes uterine contractions
7
Q
Let-Down Reflex
A
- When “gates open”
- Affected by emotional or psychologic factors
- Simulated by:
- Crying baby - even if its not your own baby
- Thought of baby
- Crying baby - even if its not your own baby
- Inhibited by:
- Embarrassment
- Stress
- Signs of successful letdown
- Dripping milk before feeding
- Dripping milk from breast opposite nursing breast
- Contractions of uterus during feeding, often causing slight pain or discomfort
- Tingling sensation in breast
8
Q
Human Milk Volume
A
- Baby demands frequent feedings
- Mother must be available at all times or use pump
- Malnutrition first affects quantity of milk
- Volume variabls depending on demand
- Average: 750-800 cc/day
- Range: 450-1200 cc/day
- Fluid requirements increase
- Feeding on demand is best way to maintain lactation → the more often the breast is emptied, the greater the volume
9
Q
Composition of Human Milk
A
- Affected by severe malnutrition
- If well nourished, independent of nutrition state except for Vit and fat content
- Basic content varies:
- mom to mom
- with stage of lactation
- with times of the day
- with gestational age of infant
10
Q
Colostrum
A
- “First Milk”
- Initiatial breast secretion first few days post partum
- Thin, yellowish, milk liquid → yellow color = high carotene content
- High in immunoglobulins → to fight infection and give baby Ab’s
- Higher that mature milk in…
- Vit A
- protein
- Na
- K
- Cl
- Lower in…
- Fat
- carbs
- calories (15 kcal/oz)
11
Q
Transitional Milk
A
- Secreted from 3-10 days post partum
- As protein content decreases → lactose and fat content increases
12
Q
Preterm Milk
A
- Mother’s body adjusts to meet needs of baby
- There is preterm milk for all types of milk, except it is different throughout all stages
- Higher in…
- Protein
- Immunoglobulins
- Ca, Na, K, Cl, P, Mg
- MCT (medium chain triglyceride)
- LCT (long chain)
- Total fat
- **Lower in lactose **
- Requires supplementation → Fe and Ca, which are normally stored during 3rd trimester - milk does not fully compensate
- Human Milk Fortifier (HMF) supplement added to milk after pumping
13
Q
Protein Synthesis
A
- Most milk proteins are specific to mammary secretions
- Formation of milk protein is induced by prolactin and further stimulated by other hormones
- Protein derived from 2 sources:
- De novo synthesis in mammary
- Plasma
- Major milk proteins:
- Casein
- Alpha-lactalbumin
- Beta-lactalbumin
- Synthesized from AA precursors
14
Q
Protein Composition - Mature Milk
A
- Lower in protein than cow’s milk → protective effect on kidneys
- Casein: phosphorus-containing proteins that occur only in milk
-
Whey
- Thin liquid of milk remaining after curd
- Contains lactalbumin and lactoferrin
- Made in mammary gland
- Not affected by maternal protein intake, unless protein malnutrition is chronic
- AA content ideal for human infant (vs. cow’s milk)
- Higher in taurine → necessary for bile acid conjucation and brain development
- Higher in cystine → necessary for growth and development
- Lower in methionine
- Cystathionase late to develop, impairing conversion of methionine → cysteine
- Hypermethioninemia may damage CNS
- Lower in phenylalanine and tyrosine
- Tyrosine aminotransferase and parahydroxyphenyl pyruvate oxidase late to develop
- Difficult to convert AA
- High levels can affect CNS
15
Q
Lipids - Mature Milk
A
- Varies
- Woman to woman
- with parity
- with season of year
- **Foremilk < Hind Milk **
- Important to empty breast completely so baby gets hind milk
- Fa profile varies with diet
- 90% of fat in form of triglycerides
- Higher levels of cholesterol and EFA’s
- Lipid content benefits
- Rapid growning CNS
- **Developent of enzymes necessary for cholesterol degradation**
16
Q
Carnitine
A
- Necessary for metabolism of LCFA’s
- Exogenous sources
- Human milk
- Cow’s milk
- Meat (carne) products
- Endogenous synthesis from lysine and methionine
- May be conditionally essentially, especially for preterm infants
- In severe stress, your requirements may exceed endogenous production
17
Q
Carbs - Mature Milk
A
-
Lactose
- Predominant carb
- Content not affected by diet
- Stimulates growth of beneficial microorganisms in infant gut, which synthesize B vitamins
- Improves absorption of Ca, P, Mg
- Synthesis cobines glucose and galactose
- Other sugars present in small amounts
- Contains amylase, which aids digestion (we cannot mimic outside the body)
18
Q
Minerals (Fluoride) - Mature Milk
A
- Strikingly different than cow’s milk
- Lower in Ca and P
- Contains almost all necessary trace elements
-
Fluoride supplementation for baby
- Rec. at 6 months for exclusively breast fed infants
- Only small amounts found in breast milk
- Maternal fluoride supplementation does not effect milk content or change rate of cavities
19
Q
Iron and Zn - Mature Milk
A
- Lower content
- Higher bioavailability (50% vs. 10% absorption)
- Fe supplementation rec by 5-6 months in breast fed infants → stores built up during pregnancy has depleted by this time, but this is okay because infant cereal usually introduced at this time and is fortified
- Lower mineral content of breast milk positively affects the amount of waste product provided to kidney
20
Q
Calcium - Mature Milk
A
- Lower than cow’s milk
- not affected by maternal diet → if dietary Ca for mom is insufficient, Ca for the baby gets taken from mom’s bones
- Maternal bone loss may occur
- Adaptations in hormonal pattern may maintain bone health in women with marginal intake
21
Q
Vitamins - Mature Milk
A
- Maternal vitamin intake does influence content of milk
- Concentrations of water-soluble are more responsive to dietary intake than fat-soluble
22
Q
Vit D - mature milk
A
- Affected by maternal diet and sun exposure
- Breast milk < Cow’s milk
- Supplementation
- Rec for breast fed infants
- 400 IUD daily beginning during first 2 months of life
- Risk factors
- Inadequate vit d intake
- Decreased sunlight exposure
- Northern latitude
23
Q
Vit E
A
- Human > Cow
- Levels in formulas now match breast milk
24
Q
Vit K
A
- Human < Cow’s
- Infant gut lacks flora to make vit K for first several days
- Newborns routinely receive Vit K at birth → Vit K shot to minimize potential bleeding
25
Q
Vit A
A
Supplementation not recommended
26
Q
B6
A
- Levels too low to meet the RDA for infants
- Most likely deficient Vitamin**
27
Q
B12
A
- Behaves like a fat soluble - storage form
- Maternal intake does not greatly affect content
- High risk groups may need supplementation
- Vegans
- gastric bypass
- Crohn’s disease or disease that compromises absorption of B12
28
Q
Resistance Factors - Mature Milk
A
- Favorable growth of beneficial bacteria
- Maternal antibodies pass to infant
- Antibacterial, antifungal, antiviral components
- Immune benefits not seen with maternal malnutrition
