Nursing Terms

Colostrum

Thick, nutrient-dense milk produced by the body in late pregnancy and in the first 2-5 days after birth

Transitional milk

Middle stage of milk that replaces colostrum about 2-5 days after birth and lasts for roughly two weeks before turning into mature milk

Mature milk

Final, permanent stage of milk production that typically establishes 10-28 days after birth

Milk transfer

Movement of milk from mother's body to baby's mouth

Let-down

Automatic physiological and neuroendocrine process that causes milk to be released and pushed down the ducts

Feeding cues

Behavioral and physical signals an infant uses to communicate hunger, readiness to eat, or fullness

Hunger cues

Physical signal baby uses to show they are ready to eat, before they start crying

Fullness cues

Physical signal baby uses to show they are full, including natural release, relaxing, slower sucking, less audible swallowing, and drowsiness or sleep

Feeding on demand

Feeding the baby whenever they show signs of hunger, rather than following a clock schedule (also known as responsive feeding)

Scheduled feeding

Feeding the baby on a clock schedule

Supplementation

Offering infant extra nourishment (expressed milk, pasteurized donor milk, or infant formula) in addition to direct nursing

Direct nursing

Feeding baby at the breast

Mammary glands

Specialized exocrine glands in female humans that produce milk to feed babies

Mammary tissue

Specialized glandular, connective, and fatty tissue

Alveoli

Tiny, grape-like sacs in mammary tissue responsible for producing milk

Lactocytes

Specialized epithelia cells inside alveoli that synthesize, store, and secrete milk components like proteins, fats, lactose, and human milk oligosaccharides

Myoepithelial cells

Specialized cells inside alveoli that help expel milk by contracting

Ductal system

Thin, straw-like tube network in mammary tissue that carries milk from the glands (lobules) to the nipple

Montgomery glands

Small, sebaceous and modified sweat glands that generate oil that is desirable to an infant

Montgomery tubercles

The external bumps on the areola that secrete oil created by Montgomery glands

Nipple pores

The small openings in a nipple that allow milk to flow out from the breast

Nipple elasticity

Anatomical variation where nipple stretches, often 2-3 times its length, into a flange when pumping

Breast fullness

Occurs between 2-5 days post birth, breasts feel heavy, large, warm, but still compressible

Breast engorgement

Peaks between 3-6 days post birth, breasts feel tight, swollen, hard, shiny

Breast edema

Swelling of breast tissue caused by blood and lymphatic fluid, not milk

Milk bleb

Small clear, white, or yellow blister on areola that is filled with trapped milk due to inflammation or blockage

Lactogenesis

The biological process of milk production in the human body

Lactogenesis I

Secretory differentiation; occurs around Week 16 of pregnancy; estrogen and progesterone start small-scale production of colostrum

Lactogenesis II

Secretory activation; after complete delivery of placenta, the rapid drop of hormones estrogen and progesterone signals the body to stop making colostrum and start making mature milk - this is when transitional milk comes out; happens around 2-5 days post birth

Lactogenesis III

Galactopoiesis; maintenance stage of milk production now controlled by the autocrine (local supply and demand) system

Autocrine regulation

The biological process by which a cell secretes some kind of signal that binds to receptors on the same cell (or identical cell type) that triggers a functional response; this is the supply and demand mechanism of mature milk supply

Endocrine regulation

The biological process by which hormones control milk production; estrogen and progesterone promote colostrum production but block mature milk production until their levels rapidly decline when the placenta is delivered, which triggers the release of prolactin that promotes mature milk production

Prolactin

Hormone secreted by the pituitary gland that stimulates milk production

Oxytocin

Hormone secreted by the pituitary gland that triggers the let-down reflex that allows milk to flow from the breast tissue and out through the nipple

Feedback inhibitor of lactation

A small whey protein present in milk that when accumulated sufficiently (breast is full), triggers the body to stop producing milk

Milk synthesis

The biological process by which the body utilizes nutrients in the bloodstream to create milk components

Milk storage capacity

The volume of milk the breasts can hold at their fullest

Foremilk

Milk from the beginning of a feeding, low in fat and watery

Hindmilk

Milk from the end of a feeding, high in fat content and nutrients

Milk fat globules

Natural lipid droplets secreted by mammary gland cells that organize milk into a stable oil-in-water emulsion

Creamatocrit

A test to determine the amount of fat in a milk sample

Human milk oligosaccharides

Complex sugars found in human breast milk that cannot be digested by the infant and act as powerful probiotics and immune-protecting agents (feed good gut bacteria, decoy receptors for pathogens, lower gut inflammation, aid in brain development)

Lactose

Primary carbohydrate and energy source in human milk

Whey

The liquid portion of milk protein that the infant can digest rapidly so that he absorbs the nutrients easily

Casein

The solid portion of milk protein that forms soft curds or clots when mixed with stomach acid, making it slower to digest; binds to essential minerals for easier absorption; keeps baby feeling full for longer between feedings

Whey-to-casein ratio

Ratio of milk protein that changes rapidly as colostrum transitions to mature milk

Lactoferrin

Multifunctional iron-binding whey protein in breast milk that binds to free iron in infant's gut to starve harmful iron-dependent bacteria (eg e.coli) and promote the growth of beneficial gut bacteria

Secretory IgA

The primary antibody found in human breast milk and the main immune protein that protects a nursing infant's digestive and respiratory tracts

Immunoglobulins

Protective antibodies that pass from a mother to the baby through breast milk to provide passive immunity and defend against infection

Lysozyme

Powerful enzyme found naturally in the whey protein of human milk that forms a crucial part of the infant's immune system

Lipase

Natural enzyme that breaks down fats so baby can easily absorb nutrients

Amylase

Digestive enzyme present in breast milk that breaks down complex carbohydrates into easy-to-absorb startched

Circadian variation

Natural fluctuations in volume and composition of breast milk throughout the 24 hour day

Melatonin

Hormone that fluctuates over a 24-hour cycle to help the baby regulate sleep and biological rhythms

Cortisol

Hormone present in human milk that follows a clear daily cycle, peaking in the morning to promote alertness and dropping in the evening to promote sleepiness

Prolactin surge

A sharp increase in lactation-promoting hormone triggered by nipple stimulation when a baby begins feeding; peaks around 30-45 minutes after the start of a feed to stimulate the replenishment of milk supply for the next feed

Rooting reflex

Automatic, involuntary survival response in a newborn where, when the corner of the mouth, cheek, or face is touched, they instinctively turn their head towards the touch, open their mouth, and move their tongue forward to find breast or bottle nipple

Sucking reflex

Automatic, involuntary survival response in a newborn where, when the roof of their mouth or lips are touched, they begin sucking to receive milk

Swallowing reflex

Automatic, involuntary process that works in coordinating rhythm with sucking and breathing reflexes so that a baby can move milk from their mouth safely to their stomach; should see 1-3 sucks then a swallow

Extrusion reflex

Automatic, involuntary survival response in a newborn where, when the lips, tongue, or mouth is touched, their tongue pushes forward to latch (also called tongue-thrust reflex)

Gag reflex

Automatic, involuntary, survival response where a baby's throat muscles contract to clear milk or prevent choking; forward-positioned during infancy (further forward on the tongue) for extra protection

Hand-to-mouth movements

Early biological tool that helps baby find and latch onto breast; stimulates mother's oxytocin via kneading; sucking on fists, fingers, or bringing hands to mouth is classic sign that they are looking to self-soothe or feed

Mouthing

Infant's intentional oral movements (opening and closing the mouth, licking, nuzzling) used to signal hunger, explore the breast, and activate feeding reflexes

Lip smacking

A distinct clicking, popping, or smacking sound made when a baby repeatedly loses suction and breaks the seal on the breast often caused by shallow latch or oral restrictions (ex tongue tie); also, early hunger cue before feeding begins

Head turning

Head position preference that causes baby to prefer one side when nursing

Early hunger cues

Subtle, silent signs a baby is starting to feel hungry, including lip smacking or other mouth movements, rooting reflex, hand-to-mouth actions, and restlessness

Active hunger cues

Also refers to mid-stage; signs that baby is actively hungry, including rooting, arching, tugging at clothes, squirming, fussing, fast breathing

Late hunger cues

Final, distress-driven signs that baby is hungry and earlier signs have been missed; includes intense crying or screaming, frantic head movements, skin turning red, full-body tension, arching, or rigidity, agitated flailing

Feeding aversion

Phenomenon where a breastfeeding or pumping parent experiences intense negative emotions that stop when baby unlatches

Feeding refusal

Baby refuses to feed at the breast (or possibly at all)

Breast refusal

Baby refuses breastfeeding but may accept bottle

Nipple confusion

Infant difficulty switching between natural breast and artificial nipple

Bottle preference

Baby favors bottle over feeding at the breast, usually because the bottle is faster (slow-flow, premie bottle nipples regardless of age can help prevent this)

Breast-seeking behavior

Organized, spontaneous sequence of instinctive actions a newborn performs to locate mother's nipple and initiate breastfeeding independently

Breast crawl

A newborn's instinct to move up to mother's breast when placed on abdomen or near breast with leg and arm movement

Self-attachment

A natural process where the newborn uses innate reflexes, sense of smell, and touch to move unassisted towards the mother's breast and latch on (similar to breast crawl)

Comfort nursing

A baby nurses at the breast for relaxation, soothing, or bonding, rather than for a full meal

Non-nutritive sucking

The sucking done by a baby on an object that will not provide milk (or an empty breast)

Flutter sucking

A rapid, quivering sucking motion a baby makes at the breast when active feeding slows down or finishes

Suck bursts

The natural, rhythmic sucking pattern of an infant while breastfeeding - usually 1-3 sucks at a time

Suck-swallow-breathe coordination

Infant's ability to blend sucking, swallowing, and breathing into a smooth rhythm during breastfeeding

Suck-swallow ratio

How many sucks to swallows a baby takes, often 1:1 during early days, active let-down, or bottle feeding; closer to 2:1 as baby matures, can get up to 3:1 with thicker hind milk or with colostrum

Audible swallowing

A clear sound that indicates infant is swallowing milk, can get quieter with thicker milk (colostrum or hindmilk), or when milk volume is low

Visible swallowing

A clear observation of baby's jaw and throat that confirms baby is actively drawing and consuming milk

Pausing during feeds

Normal action of infant to pause while feeding at the breast, can be helped with breast compressions to promote more milk flow

Cluster feeding

A pattern of behavior where baby feeds very frequently and closely together over a period of several hours, rather than following a set schedule; most commonly happens later in the day or at night; very common during the newborn-3/4 months age; often caused by growth spurts, natural instinct to boost supply, filling up for sleep, comfort; round the clock can point to latch issue or temporary dip in milk supply

Witching hour

An intense period of fussiness, inconsolable crying, or irritability in newborns and young babies that often happens between late afternoon/evening until about 12 weeks old; driven by overtiredness and overstimulation

Contact napping

A baby or infant sleeps while in direct physical contact with an alert caregiver

Feeding to sleep

Normal and biologically driven desire to feed before sleep (milk has melatonin in it) but can create issues with sleep association

Fussy at the breast

A baby cries, arches their back, pulls away, or repeatedly pops on and off the nipple during feeding

Pulling off the breast

When a baby unlatches from the nipple during a feed; can be caused by discomfort from gas, distraction, shallow latch

Squirming during feeds

Normal response to discomfort from trapped gas, milk flow issues, reflux or spit-up, poor latch, etc.

Breast compression

Hands on technique used during breastfeeding or pumping to gently squeeze the breast tissue and increase milk flow

Switch nursing

Baby is switched back and forth between two breasts multiple times during a feed to help stimulate additional letdown and increase milk intake

Feeding stamina

Infant's ability to coordinate suck-swallow-breathe pattern for a full feed

Reverse cycling

Feeding pattern where infant consumes most of their calories overnight rather than during the day

Day-night confusion

Sleeping pattern where newborn sleeps more during the day and stays awake or wakes frequently at night because their circadian rhythm has not yet developed

Wake-to-feed

Waking a sleeping baby for a scheduled feed

Dream feed

Caregiver feeds baby while baby is mostly or completely asleep to "top off" infant for the night - promotes longer sleep stretches

Positioning

How a mother holds and arranges her baby's body relative to her own during a feeding session