6/8/2020 OVERVIEW • Anatomy of the breast • Lactation hormones • Lactogenesis • Breastmilk composition Presented by: BREASTFEEDING: HOW DOES IT WORK? Ashley Denker MSN, RNC-MNN, IBCLC ANATOMY OF THE BREAST ANATOMY OF THE BREAST Exocrine Organ • •Nipple 3 Major Structures: • •Areola Skin • Pigmented circular area around nipple Corpus mammae • Darkens and enlarges with pregnancy/lactation Supportive tissues • Visual signal to newborns •Tail of Spence • Underlying ducts superficial with little underlying fat tissue (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; WILSON-CLAY & HOOVER, 2005) ANATOMY OF THE BREAST NIPPLE PORES •Montgomery Glands/Tubercules: Nipple: •Small sebaceous glands around areola •Circular smooth muscle fibers, sensory nerve •Swell during pregnancy/lactation endings & sweat glands •Secrete oily fluid •Erectile tissue •Scent Nipple pores – aka “main ducts”: •Ductile openings on the nipple surface •Average 5-9 (range 1-18) •Approximately 2mm in diameter (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; WILSON-CLAY & HOOVER, 2005) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; MEDELA, 2009) 1 6/8/2020 NIPPLE DUCTS LOBE & LOBULE Nipple ducts – “secondary ducts”, Lobe: lactiferous ducts: • Ducts branch out into lobes •Multiple ducts share a few common nipple • Average 15-25 in each breast pores • Separate compound alveolar gland in •Average 23-27 (range 11-48) which ducts drain into secondary ducts •Duct system is random and varies significantly between women Lobule: •Main function is transfer of milk • Lobes branch into lobules •Ducts widen during milk transfer, then • Average 20-40 make up each lobe collapse when milk flow ceases • Contain clusters of alveoli (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; MEDELA, 2009) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; MEDELA, 2009) ALVEOLI ALVEOLI Alveoli: •Epithelial cells (Lactocytes) • Average of 10-100 •Continuous inner lining of alveoli and ducts • Milk producing cells •Milk secreting • Smallest functioning unit of the breast • Surrounded by capillaries delivering •Myoepithelial cells nutrient rich blood to produce milk •Dense, meshwork of smooth muscle encases lactocytes Consist of: •Milk moving • Secretory epithelial cells (lactocytes) •Contract from oxytocin stimulation • Myoepithelial cells (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; MEDELA, 2009) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) ALVEOLI ANATOMY OF THE BREAST - SUPPORTIVE TISSUES •Large gaps between alveolar Nerves: Fatty Tissue: cells exist during the first 4-10 •Deep latch and vigorous sucking •Distributed between lobuli and days of life stimulate deeper nerves of breast ducts (except under areola) •Soon after the first week, the •Triggers oxytocin release and milk •More fatty tissue = larger the alveolar cells swell, letdown breast subsequently closing the •Size is not related to milk intracellular gaps producing capability (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) 2 6/8/2020 ANATOMY OF THE BREAST - SUPPORTIVE TISSUES NIPPLE VARIATIONS Blood: Common Short Shanked Flat •Provides nourishment: proteins, fats, carbohydrates, etc. •Circulation varies based on bodies needs Lymphatic System •Drains excess blood fluids from breast •Lymph nodes trap bacteria •Most lymph flows into nodes in axilla (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (WILSON-CLAY & HOOVER, 2005) NIPPLE VARIATIONS NIPPLE VARIATIONS Retracted Inverted Appearing vs. True Inverted (WILSON-CLAY & HOOVER, 2005) (WILSON-CLAY & HOOVER, 2005) ACCESSORY BREAST TISSUE ACCESSORY BREAST TISSUE •Milk Line: breasts develop from a line of glandular tissue found in fetus •Accessory breast tissue: ectopic nipples, areola, or breast tissue (CRIPEET AL., 2015; LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (WILSON-CLAY & HOOVER, 2005) 3 6/8/2020 PHYSIOLOGY OF LACTATION LACTOGENESIS Lactogenesis 1 Lactogenesis II Lactogenesis III Mammogenesis: Lactogenesis: •Growth and development of •Establishment of milk synthesis • Initiation of milk • Copious milk production • Establishment of the mammary gland and secretion synthesis • Triggered by delivery mature milk •Phase 1: onset of puberty •Begins mid to late pregnancy • Secretion begins of placenta/fall in production •Phase 2: occurs early in and continues until cessation of in the second progesterone • Continues through breastfeeding pregnancy trimester • Changes begin 30-40 lactation •3 phases • Continues for a hours after birth lasting cessation. short time after through 10 days PP delivery (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) LACTOGENESIS HORMONES OF LACTATION Delayed Lactogenesis: • Progesterone •Onset greater than 72 hours after delivery • Prolactin •Risk factors: •Retained placenta or placental fragments • Oxytocin •C-section delivery •Delay in initiation of breastfeeding (>2 hrs after delivery) •Endocrine disorders (diabetes, untreated hypothyroidism) •Maternal obesity •Preterm delivery (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) HORMONES OF LACTATION HORMONES OF LACTATION Progesterone: Prolactin: •Produced in the ovaries and placenta •Produced in the placenta and anterior pituitary •Assists with active development of milk secreting cells during •Stimulates alveolar growth during pregnancy pregnancy •Critical for the establishment and maintenance of milk production •Key inhibiting hormone for prolactin •Production triggered by delivery of placenta •Levels drop after delivery of the placenta •Credited with maternal inducing behavior •Initiates lactogenesis II (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) 4 6/8/2020 HORMONES OF LACTATION HORMONES OF LACTATION Prolactin: Oxytocin: • Release is triggered by tactile stimulus • Produced in the hypothalamus and stored in posterior pituitary • Levels are highest at night • “Mothering hormone” Interventions to maintain high levels of prolactin: • • Maternal/Infant effects: •Effective latch •Increased social interaction & synchronized responses to one another •Avoiding use of artificial nipples •Calming effect (decreased infant crying) •Unlimited infant access to breast •Increased pain threshold •Decreased cortisol levels •Skin temperature increases (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; WILSON-CLAY & HOOVER, 2005) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; MOBERG & PRIME, 2013)) EFFECT OF DELIVERY MODE ON OXYTOCIN LEVELS HORMONES OF LACTATION OF MOTHER AND INFANT Oxytocin: • Responsible for the Milk Ejection Reflex (MER) • Several minutes of stimulus is needed to produce high enough levels of oxytocin to stimulate milk letdown. • Release continues in pulse-like manner throughout feeding • Stimuli of other senses (sight, sound, smell, thought) may also trigger release • May be inhibited by physiologic, psychologic, and pharmacologic factors (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016; WILSON-CLAY & HOOVER, 2005) (MOBERG & PRIME, 2013) BREASTMILK COMPOSITION COLOSTRUM Components: Calories: •Production begins around 120 days gestation •Changes throughout lactation •The caloric content of breast •Secreted first 2-3 days after delivery milk ideal for infant •Fat, proteins, lactose, •Thick, concentrated form of nourishment carbohydrates, fatty acids, •Colostrum ≈ 18.76 kcal/oz hormones, enzymes, peptides, •Laxative effect •Around two weeks breast milk growth factors, vitamins, •Aids in rapid gut closure minerals ≈ 20 kcal/oz •Intake can range from 3-32 mL/kg in first 24 hours •List is continually increasing •Around 4 months increase to ≈ 26 kcal/oz (LAUWERS & SWISHER, 2016) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) 5 6/8/2020 COLOSTRUM PRETERM MILK •High in antibodies Higher in fat, protein and total energy composition •Rich in white cells and antibodies •High in protein •Contains a high percentage of protein, minerals, and fat–soluble vitamins A, E, and K •Yellow color derived from vitamin A content (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (BALLARD & MORROW, 2013) TRANSITIONAL MILK MATURE MILK •Changes within 4 days after birth •Gradually changes within 2-3 weeks •Lasts up to 2 week postpartum •Contains all the nutrients needed by an infant in the first 6 •Decrease in immunoglobulins and total proteins months of life •Increase in lactose, fat, and total caloric content •Largest component is water •24 hour volume increases to 556-705 mL •Second largest component is lipids (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) (LAUWERS & SWISHER, 2016; LAWRENCE & LAWRENCE, 2016) MATURE MILK - LIPIDS MATURE MILK - PROTEINS •Fat concentration varies •Proteins include whey and casein (among other •Fats provide one half of the energy content components) •Cholesterol concentrations remain consistent regardless of •Comparision ratio of whey proteins to casein: maternal diet •Breastmilk = 1.5, meaning 40% casein & 60% whey •Formula = 0.25, meaning 80% casein & 20% whey (LAWRENCE & LAWRENCE, 2016) (LAWRENCE & LAWRENCE, 2016) 6 6/8/2020 MATURE MILK - CARBOHYDRATES MATURE MILK - ENZYMES •Main carbohydrate is lactose •More than 20 active human milk enzymes •Carbohydrates have bifidus factor activity •Three categories by function: •Lactose is essential for calcium and iron absorption and •Mammary gland function CNS development •Compensatory digestive enzymes •Milk enzymes •Levels are relatively constant, despite maternal diet (LAWRENCE & LAWRENCE, 2016) (LAWRENCE