Breast Feeding Flashcards
Current Recommendations
- Breastfeed exclusively for first 6 mo then start to complement w/ food but continue breast feeding for full yr and beyond
- If contraindication, consider whether it may be temporary in which case mom should pump to maintain lactation abilities
Benefits (mom and baby)
- In infant … associated w/ dec risk OM, gastroenteritis, severe lower resp tract infections, atopic dermatitis, asthma, obesity, type 1 and 2 DM, childhood leukemia, SIDS, necrotizing enterocolitis
- In mom… associated w/ dec risk of type 2 DM, breast cancer and ovarian cancer; early cessation or no breastfeeding associated w/ inc rate of postpartum depression
What are the main nutritional components of breast milk?
- Fats - long chain polyunsaturated FAs (including docosahexaenoic and arachidonic acids not found in cow’s milk but important to brain development)
- Carbs - lactose and oligosaccharides
- Proteins - less protein conc than cow’s milk and diff protein composition (casein and whey)
- Casein - human milk has less and softer/easier to digest form
- Whey - more alpha form while cow milk has more beta form
General Categories of Formula
- Cow’s Milk Based - add some nutrients, vitamins and minerals and remove others
- Soy Based - contain phyto-estrogens
- Protein Hydralysates - add proteases to cow’s milk to breakdown proteins into smaller pieces; less allergenic
- Neocate - elemental; start w/ AAs
- Special formulas for infants w/ kidney failure and other problems
Mammogenesis Timeline
- 6-8 wks gestation - inc size and vol of breasts w/ vascular changes; nipples become enlarged, pigmented and erectile
- 2nd trimester - huge cellular hyperplasia then hypertrophy
- Proliferation of epithelium ceases halfway thru preg (dec # mitoses)
- Next - alveolar tissue starts to differentiate into secretory epithelium (inc # golgi and RER)
- End of gestation - alveoli fill w/ amorphous material (proteins, desquamated cells, leukocytes); stromal structure replace almost entirely by glandular tissue b/f delivery
What is colostrum? When can it first be prod?
- Early breast milk; first milk formed in preg
- Can be made as early as 16 wks if mom delivers
How is lactation prevented during pregnancy?
- During preg - sex hormones block prolactin so no milk excretion
- Progesterone is a casein mRNA antagonist
- At delivery - decline in progesterone –> inc milk synthesis
Stages of Lactogenesis
- Lactogenesis I (Secretory Differentiation) - early 3rd trimester; inc lactose, proteins and Ig while dec Na and Cl; gathering substrate to begin milk prod; cont until delivery
- As progesterone falls and prolactin high –> this milk synthesis inc independent of infant suckling BUT only lasts 3-4 days if milk is not emptied from breast
- Lactogenesis II (Secretory Activation) - when mom senses inc in her milk volume (usually at day 2-4 after delivery); inc citrate, glucose, Ca and fall in pH of milk
- Peak plasma alpha-lactalbumin
- **Milk composition cont to change for about 10 days until “mature milk” established (sometimes this is called lactogenesis III)
Hormonal Regulation of Lactation
- Infant sucks –> nipple/areola nerve endings –> ant pituitary –> oxytocin and prolactin release
- Oxytocin - milk ejection (acts on myoepithelium)
- Prolactin - milk production
- Also GH, thyroid hormone, insulin, cortisol
4 Major Players in Breast Milk Immune Function
1- IgA
- Pathogen enters mom’s gut –> sampled by Peyer’s patches –> presented to underlying lymphatic cells –> IgA made on basolateral side of mammary cell –> IgA traverse mammary cell to milk –> in gut of newborn
2 - Lactoferrin
- binds iron for inc absorption but also bacteriostatic b/c uses iron b/f bacteria can
3- TGs
- digested into free FAs and monoglycerides by baby’s lingual and gastric lipases –> toxic to enveloped viruses and some parasites
4- Glycans
- carbs that engulf pathogens to prevent them from attaching to intestinal mucosa of baby (ex - norovirus normally binds glycan receptors in gut but now bind glycans from breast milk)
