module 4: lactation Flashcards
Discuss the effects of progesterone, prolactin, oxytocin, and placental lactogen on breastfeeding.
- Progesterone: plays a role in alveolar development after onset of menses and during pregnancy
- Prolactin: promotes milk production, stimulated by suckling (anterior pituitary, endocrine modulated)
- Oxytocin: responsible for ejection of milk from the myoepithelial cells, stimulated by suckling or nipple stimulation (posterior pituitary, nervous system)
- Placental lactogen: responsible for alveolar development during pregnancy
progesterone
plays a role in alveolar development after onset of menses and during pregnancy
prolactin
promotes milk production, stimulated by suckling (anterior pituitary, endocrine modulated)
oxytocin
responsible for ejection of milk from the myoepithelial cells, stimulated by suckling or nipple stimulation (posterior pituitary, nervous system)
placental lactogen
responsible for alveolar development during pregnancy
Describe the process of lactation.
Mechanoreceptors in nipples promoted through suckling
- Oxytocin causes contraction of myoepithelial cells surrounding alveoli, which leads to milk ejection
- Prolactin causes secretion by alveolar epithelial cells which leads to milk secretion
Describe the different phases and types of breast milk.
Colostrum: 0-4 days PP, high protein and immunoglobulins low lactose and fat
Transitional Milk: 4-10 days PP, high fat and lactose, lower protein and immunoglobulins
Mature Milk: 10 day PP, 60-80% whey protein, 50% fat
How does fat get into the breastmilk?
- Fat is the most highly variable macronutrient of human milk
- Synthesis of fatty acids
- Presence of fatty acids in milk is highly dependent on the fatty acid content of the maternal diet
- Synthesis of TAG and phospholipids
- Assembly of lipid droplets
- Formation and secretion of milk lipid globule
Describe the stages of lactogenesis
I: first few days after birth, milk formation begins
II: two to five days after birth, increased blood flow to breast; milk comes in
III: about ten days after birth, milk composition is stable
What are the health benefits of breastfeeding to the mother?
Hormonal Benefits: increased oxytocin stimulates uterus to return to prepregnancy status
Physical Benefits: delay in monthly ovulation resulting in longer intervals between pregnancies
Psychological Benefits: increased self-confidence and bonding with infants
What are the health benefits of breastfeeding for the child?
Nutritional Benefits: optimal nutrition, balanced nutrients, meets protein needs without overloading kidneys, contains soft/digestible curd, lipids, LPUFAs, enhanced availability of minerals
Immunological Benefits: infection protection, lower infant mortality, fewer acute illnesses, reductions in chronic illnesses (reduce risk of celiac, IBS, leukemia, allergies, asthmatic disease)
Other: breastfeed infants are learner, cognitive benefits, analgesic = reduction of infant pain, decreased medical care and lower medical costs
What types of compounds and nutrients are found in breast milk that make it so beneficial? (You do not need to memorize the full list, but know the types of compounds that are found)
Cells: macrophages, stem cells
Ig’s: IgA/M/G
Cytokines
Chemokines
Cytokine Inhibitors
Growth Factors
Hormones: calcitonin, somatostatin
Anti-microbial: lactoferrin, lactadherin
Metabolic Hormones: adiponectin, leptin, ghrelin
Oligosaccharides/Glycans: HMOs, gangliosides, glycosaminoglycans
Mucins: MUC1/4
What are some of the contributing factors to delays in breastfeeding?
- lactation problems
- lack of knowledge
- poor family and social support
- social norms
- embarrassment
- employment and child care
- health services
What are some nutritional considerations during lactation?
- 500 excess calories during the day
- increased water intake, ~3000ml
- multivitamins like postnatal supplements
- ensuring proper vitamin D intake/exposure
- limit caffeine
- no alcohol
What are the major macronutrient compositions of mature, term milk? How does it differ from cow’s milk?
Mature term milk is composed of carbohydrates, lipids, and proteins
Cow’s milk has a lot more casein and less immunoglobulins than human milk; human milk has less protein
