Chapter 5.1 - Breastfeeding PDF

Chapter 5 – Part I Introduction to Lactation Breastmilk Protein Composition Anatomy of the female breast Fat and connective tissue, lobes, lobules, ducts, and lymph nodes Muscle tissue separates breast from ribs Lymph nodes produce lymphocytes that help defend the body against microorganisms and har...

Chapter 5 – Part I Introduction to Lactation Breastmilk Protein Composition Anatomy of the female breast Fat and connective tissue, lobes, lobules, ducts, and lymph nodes Muscle tissue separates breast from ribs Lymph nodes produce lymphocytes that help defend the body against microorganisms and harmful particles During breastfeeding, ducts carry milk from the alveoli toward the areola, where they join into larger ducts ending at the nipple Milk-producing structures are nearly the same in all women, regardless of breast size milk producing based on supplying gland —> how much the baby is suckling/needing will indicate how much milk is produced Hormone control and breastmilk production Milk production based on supply and demand Lactation involves nerves and hormones, hypothalamus and pituitary gland (prolactin and oxytocin) Infant’s suckling stimulates pituitary gland to release prolactin and oxytocin Suppressed ovulation (↓estrogen and progesterone; ↑prolactin) Slow or inhibited let-down may be caused by Embarrassment, pain, stress, anxiety, cold, smoking, excessive caffeine use, or use of some medications Prolactin from anterior pituitary stimulates milk production by alveolar cells in mammary glands Prolactin causes alveoli to take nutrients from blood and convert them into breastmilk Oxytocin from the posterior pituitary stimulates myoepithelial cells of mammary glands to contract “milk let-down” and “mothering” response Breastfeeding Infants are born with the ability to feed. Sucking instinct and rooting reflex help with successful breastfeeding. Communicate hunger through cues Help parent understand baby’s needs Begin when baby starts to feel hunger Become more persistent as hunger intensifies Cry and create more agitated movements when hunger becomes severe Parent must calm baby before attempting to feed. Best time to feed: Right before signs of middle stages of hunger manifest Breastfeeding positions and latch Position: navel to navel Nipple should be in line with center of baby’s lower lip Mother and baby should have eye contact Wide mouth latch so that chin and nose are in contact with the breast Latch: process whereby infant creates right type of contact for positive pressure to initiate flow of milk Mouth must close around areola. Shallow latch that compresses the nipple results in pain and inefficient milk transfer. Breastfeeding positions and latch Average infant: Suckles for 10–30 minutes per session Removes 80–90% of existing milk within breast per session Feeds 8–12 times per day and should be fed when showing signs of readiness Should empty one breast before other is offered Infant not latching properly can result in: Nipple discomfort Plugged ducts Mastitis (inflammation of mammary gland) Decreased milk supply Breastfeeding positions and latch Use of artificial nipples or pacifiers discouraged until breastfeeding is well established to avoid nipple confusion Only way to increase amount of milk available is through increased suckling at the breast. Most infants settle into pattern of feeding with 3- to 4-hour breaks between feeds. Engorgement generally occurs in early periods of breastfeeding when baby is unable to remove milk at the rate mother produces it. Actual and perceived barriers to breastfeeding Lack of knowledge about specific benefits of breastfeeding Perceived inconvenience of breastfeeding Difficulties in establishing breastfeeding Returning to work Sore nipples Engorged breasts Mastitis Pain Baby’s failure to latch Benefits of Breastfeeding Breastmilk enhances passive immunity can’t replicate it in formula Passes antibodies from mother to infant Contains a variety of anti-infectious agents & immune cells Most useful in protecting against bacterial infections capacity of vaccination Not as effective as vaccinations for preventing viral disease enhance to work through some unknown Decreases risk of other conditions Otitis media Upper respiratory tract infections Inflammatory bowel disease (IBD) Diabetes Sudden infant death syndrome (SIDS) mechanism Benefits of Breastfeeding) Breastmilk nourishes the probiotic flora of gut. Infants fed breastmilk exclusively for 6 months have half the rate of hospitalization for diarrhea compared to formula Reduced risk of necrotizing enterocolitis in preterm infants who are breastfed Possible risk reduction for allergies if exclusively breastfed for 4–6 months Benefits of Breastfeeding May have protective effect on child overweight and obesity Induces lower plasma insulin levels, which decreases fat storage and prevents excessive early adipocyte development Reduces likelihood of developing cardiovascular disease or experiencing metabolic disturbances associated with obesity later in life Benefits of Breastfeeding Enhances the infant’s comfort and stability in a new environment Breastfeeding with skin-to-skin contact is superior to all other methods of pain control. Benefits of Breastfeeding Mothers who breastfeed for at least 6 months are more likely to return to their prepregnancy weight Chronic diseases reduced by breastfeeding: Diabetes (both type 1 and type 2) Obesity Hypertension Cardiovascular disease Hyperlipidemia Some types of cancer especially ovarian and breast cancer Benefits of Breastfeeding Reduces financial burden of parenting Breastfeeding family saves approximately $1,700 per year in formula costs Mothers who breastfeed tend to: Miss fewer workdays Have increased productivity Report less infant maltreatment bc better bonding from breastfeeding Benefits of Breastfeeding Readily available nutrient source available at no cost Reduces infant death rates Significant decrease in occurrence of SIDS More likely to return to prepregnancy weight Lesser visceral adiposity, waist- to-hip ratio and waist circumference Improved intestinal function Possibly reduces risk of cancer development Reduces metabolic disease Improves maternal well-being Positively associated with child intelligence ↓ Diarrhea and respiratory infections in infants Milk Constituents Complex fluid of > 200 constituents ↑ with increasing sophistication of analytical techniques Compartments Micelles, membrane-bound globules, live cells, protein & NPN compounds, CHOs, lipids; vitamins, minerals & trace elements Three Sources of Milk Components Transferred from maternal plasma Synthesized from maternal secretory (alveolar) cells from maternal plasma precursors Synthesized from other mammary cells in situ Hormone control and breastmilk production Lactogenesis I (first few days after birth) yellowish fluid bc rich in carotenoids —> prebiotics + antioxidants Mother’s body produces colostrum, which contains immune factors that newborns cannot receive from another source Lactogenesis II (begins 2–5 days after birth) Production of transitional milk transition to more mature milk from colostrum Changes in breast tissue signal the body to increase concentration of lactose for about 2 weeks Lactogenesis III (2–5 weeks after birth) produces depend on how much milk infant wants Milk stabilizes in composition and volume. milk after 6 months usually goes down bc starts eating other foods Amount of milk consumed typically the amount infant will consume throughout the first year of life Three Phases of Milk Production Colostrum (first 5 – 7 days) Relative to mature milk bc higher rate of growth preterm milk infant even higher in protein bc faster rate of growth —> usually fortified with calcium and vit D bc not enough in milk itself to generate optimal growth ↑Protein and mineral (Na, K, Cl) content ↓Energy, fat and lactose content The first hour of post-natal life → the “Golden Hour” Critical and sensitive period for newborn’s health outcomes Timely initiation of breastfeeding → ↓ risk of neonatal mortality Three Phases of Milk Production Transitional milk (7 days to 3 – 4 weeks) ↓ Protein content to consistent level ↑ Lactose and fat Mature milk Changes according to the changing infant’s needs Immunological Properties of Human Breast Milk Direct action against pathogens Modulation of immune response against entry of pathogens in systemic Promotion of growth and maturation of GI tract protects circulation growth factors help protects against it Anti-Infectious Agents in Human Breast Milk Immunological factors: Produced throughout lactation Some factors are highest in colostrum Most immune factors Not found in infant formula new technologies being developed to try to replicate immunological factors Lower concentrations in cow’s milk most of them in whey part Anti-Infectious Agents in Human Breast Milk Whey proteins are resistant against proteolysis/acid Anti-proteases (e.g. sulfhydryl oxidases) Protect proteins by preserving their S-S bonds prevent globular structure to be degraded Anti-Infectious Agents in Human Breast Milk Antibodies (IgA, IgM, IgE and IgG) B Cells travel to mammary gland; form plasma cells producing IgA IgA: protective against many pathogens B Cells originate from maternal sites where ↑ exposure to pathogens Anti-Infectious Agents in Human Breast Milk Bifidus factor: N-containing CHO, promotes growth of lactobacilli Lactobacilli: dominant bacteria of the lower GI of breast-fed infants Secrete organic acids that inhibit pathogenic bacterial overgrowth. Anti-staphylococcus factor Lysozymes – break down proteoglycans Anti-Infectious Agents in Human Breast Milk pathogens Lactoferrin: inhibits siderophilic bacteria Competes for Fe Because: 80% in Apo form binds easily Lactoperoxidases kill Streptococci and enteric bacteria monoacylglycerol Lipases  fat breakdown in gut  FFA & MAG have antiviral properties milk —> semi solid: more exposed to bacteria and virus that can cause infections body fat —> can rely on it when problem with feeding during infection —> increase breakdown of TG —> FFA + MAG that have protective effects itself Anti-Infectious Agents in Human Breast Milk Interferon: inhibits intracellular viral replication B12 – binding protein Neutrophils: phagocytosis Macrophages: synthesize complement, lactoferrin, lysozymes and carry out phagocytosis Anti-Infectious Agents in Human Breast Milk Lymphocytes: synthesize secretory IgA & other Ig’s Fibronectin: ↑ phagocytosis Complement: promotes opsonization Growth Factors in Human Breast Milk Cortisol/thyroxine/insulin: stimulate synthesis of intestinal enzymes & maturation of gut mucosa Insulin-like growth factor: ↑ rate of gut maturation Prostaglandins: stimulate mucus secretion & cell division Polyamines (spermine and spermidine): growth factors; increase likely of leakage of pathogens into systemic circulation cell replication less same proteins that are absorbed from GI tract are less likely to go into systemic circulation as whole protein Milk Proteins Human breast milk (9 g protein/L) Infant formula (12-19 g protein/L) higher concentration provided Caseins – complexes of caseinates found in micelles in combination with Ca, Mg, and Phosphates Whey – thin liquid remaining after removal of the acid precipitate of the curd and removal of cream immune factors are in whey portion Protein Composition (mg/dL) of Human and Bovine Whey Constituent α-Lactalbumin Lactoferrin Cow Human 17 42 -- 27 β-Lactoglobulin cause allergenic response 57 can Serum Albumin 40 IgA 3 100 60 3 Nonprotein Nitrogen 28 50 Osteopontin 18 157 IgG associated with colic (crying all the time from pain bc of intestinal discomfort) —> allergenic response -- immune enhancing property and more bioavailable form of iron compared to formula with 50 helps development of mucus —> protection binds to pathogens and prevent its entry can arrive in breastfeeding, but less likely Advantages of Human Milk vs. Bovine Milk (Infant Formula) in Terms of Nutrient Content Whey:Casein Ratio Overall ratio = 60:40 in human milk (ranges from 70:30 – 80:20 early lactation to 50:50 late lactation) 40:60 in cow’s milk formula (humanized infant formula matches human milk ratios) Higher proportion of nucleotides Better balance of essential a.a.’s Decreased risk of allergenic reaction Advantages of Human Milk vs. Bovine Milk (Infant Formula) in Terms of Nutrient Content Lactalbumin: binds Ca and Zn Lactoferrin (Fe-binding protein) Xanthine oxidase: binds Fe and Mo Glutathione peroxidase: binds Se Proteases, lipases and amylases Beta-lactoglobulin: responsible for most of the antigenicity of cow’s milk Polyamines, nucleotides (orotic acid) may play a role as growth factors in the human gut. Advantages of Human Milk vs. Bovine Milk (Infant Formula) in Terms of Nutrient Content IgG closely associated with infant colic Non-protein nitrogen = 15-25% of all N in human milk = a.a.’s, peptides, N-acetyl sugars, urea and nucleotides Polyamines, nucleotides (orotic acid) may play a role as growth factors in the human gut. Osteopontin may improve growth, brain and immune system development Significant Features about Amino Acid Composition of Human Milk Characteristic Explanation Rich in Taurine Needed for bile acid conjugation Putative neurotransmitter Conditionally essential amino acid Significant Features about Amino Acid Composition of Human Milk Characteristic Explanation Lower methionine and rich in cysteine Cystathionase is late to develop XS blood Met may adversely affect CNS Lower phenylalanine and tyrosine Tyrosine aminotransferase and para-hydroxyphenyl pyruvate oxidase are late to develop XS blood Phe and Tyr may adversely affect CNS Cow’s Milk Allergy Occurs in about 2 – 7.5% of infant Clinical signs: GI tract – vomiting, nausea Respiratory – sneezing, wheezing, chronic cough Skin – dermatitis Neurological – headaches Increased permeability of food proteins in young infants Management: casein or whey protein hydrolysates Protection of Breastfeeding against Milk Allergy IgE and food proteins interaction: complex binds Fc receptor on mast cells/basophils  cytokines, interleukins and platelet activating factor  inflammatory response in part via histamine IgA: aids in the blockage of whole food proteins from absorption by binding them IgA-food protein complex promotes mucus release from goblet cells and proteolysis at the mucosal surface Protection of Breastfeeding against Milk Allergy Blood IgA: binds to food proteins  out via reticuloendothelial system Infants have leaky junctions in the GI tract which allow antigens to pass through Colostrum hastens closure of leaky junctions Heiner’s Syndrome Hypersensitivity to cow’s milk protein (unheated cow’s milk) GI blood loss and iron deficiency anemia Failure to thrive