Breastfeeding Flashcards
Current Recommendations for Infant Feeding
- Exclusive breastfeeding for first 6 months of life
- Breast feeding can continue for 2+ years
- iron-fortified is the only alternative to breastmilk for the first 6 months
- solids can be introduced after 6 months
optimal method of feeding infants
breastfeeding
What is exclusive breastfeeding?
Only breastmilk
* Includes: Breastmilk fed from the breast and expressed breastmilk with inclusion of supplements and medicine
* not including: water, formula other liquids or solids
Benefits of breastfeeding for the Infant
- contains all the nutrients the infant needs in the ideal proportions
- helps development of the intestinal tract and immune system
- lower risk of infections, allergies, SIDS
- associated with enhanced cognitive development and lower risk of obesity
Benefits of breastfeeding for the mother
- economical and generally convenient
- promotes weight loss
- psychological benefits from the physical contact
- delayed return of fertility
- associated with lower risk of breast and ovarian cancer
Lactation
- the production of milk
- the period following childbirth when milk is formed in the breasts
breasfeeding
the process of nourishing an infant at the breast
What is the main organ of lactation and breastfeeding?
Mammary glands
* alveolus is active machinary
* contractile unit to get milk out
Where do lactation materials come from?
“Raw materials” supplied by maternal circulation (maternal stores, diet) and may be transported in and out of aveolar gland cells or “processed” in the gland cells and then final product secreted into ducts in centre of cluster of alveoli
What are the stages of lactation?
- Stage I: Starts in late pregnancy; prep action
- Stage II: 3-10 days post-partum
- Stage III: ~10 days post-partum
Key hormone of lactation
Prolactin
* levels rise from early pregnancy and develop secretory portions of gland
What occurs in stage I lactation?
- increased lactose, protein, immunoglobulin in gland in third trimester
- first fluid after delivery: colostrum (1-3 days)
What occurs in stage II lactation?
3-10 days post-partum
* secretory activation and transitional milk
* increased blood flow and glucose uptake –
“milk comes in” reflecting supply and demand
What occurs in stsge III lactation?
~10 days post-partum
* mature milk
Initiation of the FIRST lactation
At delivery of placenta, abrupt ↓ in human placental lactogen, estrogen and progesterone
* removal of estrogen and progsterone are triggers for milk secretion
What hormones maintain lactation?
- Prolactin (anterior pituitary)
- Oxytocin (posterior pituitary)
Role of prolaction
stimulates milk production
* levels high in first weeks, gradually decline but rise with sucking
Role of oxytocin
release of milk
* stimulated by sucking, sound of baby crying, sex etc.
* triggers contraction of myoepithelial cells to permit milk ejection = let-down reflex
What is important about environment for oxytocin?
mother breastfeeding needs to be in a relaxed environment as stress can reduce stimulus
How much breastmilk is produced?
Production related to demand
* Increased production in feeding multiples
* Production is not dependent on breast size
Basic principles of breastfeeding
- started during the alert period immediately after delivery
- feeding “on demand” rather than by schedule so typical newborns will feed 8-12 per 24 hrs
- offering 1st breast until finished, then 2nd breast; next feeding offer the second breast first
Early infant cues of hunger
hands to mouth, head movement
* crying is not an early cue
Key to optimal breastfeeding?
Correct positioning of baby and correct latching
* allows baby to get milk and should not be painful
What is “the art” of sucking?
When “letdown” induced, sucking becomes slow, rhythmic
* suck-swallow-breathe pattern
How long should active feeding be and what is the satiety cue?
- Active feeding 5-20 min (maximum ~30 min)
- satiety cue: baby releases breast spontaneously
What is a later cue of hunger?
crying
What are the types of breastmilk?
- colostrum
- transtional milk
- mature milk
What is the first breastmilk?
Colostrum (day 1-3)
* yellow color due to beta-carotene
* low volume (2-10 ml/feed)
* lower energy
* higher protein (IgA, lactoferrin) and growth factors
* adequate to meet infant needs in first few days
What nutrients might vary in breastmilk composition?
- macronutrients: not the amount of fat but the types of fat are what will change
- water soluble: B vitamins; thiamin; riboflavin; niacin; B6; B12; choline; vitamin C
- fat soluble: vitamin A; vitamin D
- minerals: iodine
What components of breastmilk do not depend on maternal diet?
- macronutrients: CHO (uptake always maximal), proteins
- water soluble: folate
- fat solbule: vitamin E
- mineral: all except iodine
mature breastmilk compostion
Mature milk composition varies
* night/morning vs afternoon/evening
* early in feed vs later in feed
How does night/morning vs afternoon/evening vary mature breastmilk?
night/morning is lower in fat
How does early in feed vs later in feed vary in mature milk?
foremilk (early in feed) higher in lactose and lower in fat than hindmilk (later in feed)
* hence critical for baby to feed on one side completely so they get both foremilk and hind milk
What is the average nutrient composition of mature milk?
energy content: 0.67 kcal/g
* 55% lipid
* 38% lactose
* 7 % protein (very bioavailable)
How much mature breastmilk is produced?
700-900 g produced each day
* less if partially breastfeeding such as starting to eat solids
What is the CHO in breastmilk?
Virtually 100% the disaccharide lactose: glucose and lactose
* also contains some oligosaccharides
What are the oligosaccharides important for?
May prevent pathogenic organisms from binding to gut and promotes growth of ‘good’ bacteria (prebiotic)
* microbiome development and infection prevention
What is the PRO in breastmilk?
- Most abundant: casein, α-lactalbumin, lactoferrin, sIgA, lysozyme, serum albumin
- 20% of nitrogen non-protein: including urea, free amino acids, nucleotides
How much protein is in breastmilk?
- 10 g protein/L breastmilk
How is breastmilk different from cows milk?
Qualitatively different from cow milk
* Human milk: 70% whey, 30% casein
* Cow milk: 20% whey, 80% casein
What is the benefit of higher whey content in breastmilk?
- Easier to digest
- More rapidly digested/ emptied from stomach
- Soluble in acid
- High in leucine and can be directly anabolic to muscle through mTOR pathway