Lecture 7 Flashcards
Lactation and Human Milk
Lactation Physiology: Alveoli
Are the functional units of the mammary gland
Each alveolus has a cluster
of cells (secretory cells) with a duct in the centre to secrete milk
Ducts are arranged like
Branches of a tree with each smaller duct leading to 6-10 larger collecting ducts, leading to the nipple
…… surround the secretory cells and contract under the influence of …. and cause milk to be ejected into ducts
Myoepithelial cells
oxytocin
Within each lobes there are …
Within each lobes there are lobules within the lobules are the alveoli, there are a large number of blood cells surrounding to bring hormones to the cells
Mammary gland Development: Puberty
-Ovaries mature and increase in estrogen and progesterone initiates mammary lobular structures (lobes) complete 12-18 mo after menarche
What increases around the duct
Fibrous and fatty tissue
Ductal system matures and
Nipple grows with pigmentation change
Mammary Gland development: pregnancy
Human chrionic gonadotropin and ……
Human chrionic ganadotropin and placental lactogen allow further preparation
Mammary Gland development: pregnancy
Estrogen stimulates
Development of glands that will produce milk
Mammary Gland development: pregnancy
Progesterone allows
The tubules to elongate and epithelial cells that line the tubules to duplicate
Lactation hormones
Prolactin
Oxytocin
Prolactin stimulates
Milk production via suckling (baby)
Suppressed by prolactin inhibiting factors released by the hypothalamus during the last 3 mo pregnancy to allow for the body to prepare for milk productiomn
Oxytocin stimulates
Ejection of milk from the milk gland into ducts via suckling (baby)
also known as ‘Letdown’
feels like tingling, tightning or shooting pain 1min=contraction in milk ducts
also acts on the uterus during and after delivery, causing it to contract (shrink back to pre-pregnancy size)
Lactogenesis
Milk production
Lactogenesis 1
Colostrum
- Produced in 1st few days
- Low milk production
- High levels of white blood cells, immunoglobulin A, Vitamin A
- High protein, low fat
Lactogenesis 2
Transitional milk
- Produced after 1st couple of days up to - 10 days
- Increased milk production, stimulated by maternal hormones
-Higher protein and lower fat than mature milk
Lactogenesis 3
Mature Milk
-Begins around 10 days postpartum
-780ml consumed by infants on average during exclusive breastfeeding from 0-6months
-Milk composition is more stable
Breastfeeding initiation
within the first hour of birth
Healthy term infants with reflexes to feed
Suck and swallow
Oral search reflex
Rooting reflex
Suck and swallow in a coordinated pattern
Includes a gag reflex to prevent food and fluids into the lungs
Oral search reflex
Open mouth wide in proximity to breast and thrusting tongue forward
Rooting reflex
Turn to head to side when stimulated on side of upper or lower lip
Mechanics of breastfeeding :
Suction created …..
within babys mouth causes the mothers nipple and areola to elongate and form a teat
Mechanics of breastfeeding :
Babys jaw
moves her tongue toward the areola, compressing it and causing milk to travel from the milk ducts to babys mouth
Mechanics of breastfeeding :
Baby then raises anterior
portion of tongue and depresses and retracts posterior portion of tongue= peristaltic motions forming a grove in the tongues that channels milk to back of oral cavity
Mechanics of breastfeeding :
Receptors in back of babys
Oral cavity initiate swallow reflex
Mechanics of breastfeeding :
Key to success
Proper latch and positioning
Establishing breastfeeding
-Skin-to-skin contact
-Staying hydrated
-Responsive feeding
-Emptying breasts -removal signals production
The more the baby is feeding on the breast the more
milk that is being made
Typical milk production
600ml in first month 750-800ml by 4-5 month
can range from 450 to 1200ml per day in one infant
Inreases to meet demand (twins, triplets -no problem
Lactation support
Midwives and Lactation Consultants
How much water makes up breastmilk
about 88% of water
women need to remain …. during pregnancy
Hydrated (drink to thirst)
where does the energy in the breastmilk come from
The largest component is fat (lipids).
-Fat is low in beginning (foremilk) and high at the end (hindmilk)
-Correlated with the mothers diet, including trans fatty acid intake
-Contains cholesterol, essential component of all cell membranes
Protein in breastmilk
Protein content of mature milk is relatively low
Classes: Whey, casein and non-protein nitrogen (nucleotides)
Carbohydrate in Breastmilk
Mostly lactose which enhances calcium absorption
Oligosaccharides ???
Human milk oligosacharides
Prebiotic -a function ingredient of human milk
- Stimulate growth of bifidus bacteria and inhibits Escherichia coli
-Prevent binding of pathogenic microorganisms to the surface receptors of their target cell= preventing infection
Vitamins and minerals
Micronutrient categories based on the effect of maternal intake and status on the micronutrient content of breast milk
Vitamins and minerals:
Group 1
Affected by maternal status
Vitamins and minerals:
Group 2
Not affected by maternal status
Group 1 nutrients:
Low maternal intake or ……… which affects ……..
Breastmilk can be restored by……
Infant stores are low and …..
stores reduce the amount in breast milk
- affects infant development
-Breastmilk concentration can be restored by increasing maternal intake
-Infant stores are low and readily depleted, depend on adequate supply form breast milk
Influence of maternal intake and status on breastmilk
If the supplementation of certain nutrients increased the deficiency of the status decreases
Iron in human milk
Iron concentration is low in human milk but is highly bioavailable
Iron in breast milk compared to formula
Approximately 50% of iron in BM is absorbed compared to 10% or iron from cows milk based infant formulas
this is why they put a lot of iron into infant formulas because they know that only 10% can be absorbed
Human milk contains an important substance called …..
Lactoferrin
-Lactoferrin is a protein with an anti-tumor effect, and has been found to significantly inhibit the growth of some cancerous cells
-It also helps our little ones to absorb their own Iron stores
-It binds to the iron inn their body, which prevents it from being accessed by harmful micro-organisms that need iron to survive
Iron deficiency: infants reserves at birth….
Infants reserves at birth is a major determinant of anemia risk during infancy
Breast milk provides sufficient iron until the infant is
6 months
Sustained Iron deficiency may be associated with…
irreversible and detrimental effects on intellectual and motor performance (irreversible)
Vitamin D in Breastmilk
Breastmilk is low in Vitamin D (20-70 IU/L)
- Infant formula is fortified with 200 IU/L
Low Vitamin D status in infants can result in
Rickets =soft , weakened bones
To increase the Vitamin D content of breast milk requires…
For every….
The mother to consume high dose supplmental vitamin D
For every 1000 IU/day of vitamin D consumed by the mother breast milk vitamin D concentration increases by approximately 10IU/L
A study carried out in auckland with Vitamin D showed
The mothers supplement was sufficient to help the mothers status but not the babies, so now it is recommended that each baby that is breastfed then they need to be given the supplement directly
Recommendation: NZ Supplementation of Vitamin D for breastfed infants
-Exclusively or partially breastfed infants may benefit from vitamin D supplementation
-Vitamin D supplementation is appropriate until the infant is mobile, or up to 12 months of age
-Should be offered as a prescription by 4 weeks of age
