IBCLC key terms

The first stage of milk production, beginning during pregnancy, when the breast develops the capacity to secrete milk. Volume is small, and secretion is driven largely by hormones rather than by infant demand.

The onset of copious milk secretion, usually 30 to 72 hours after birth, triggered by the fall in progesterone after the placenta is delivered. It is marked by breast fullness and a shift from colostrum to transitional milk.

The maintenance phase of milk production, controlled mainly by how often and how completely milk is removed from the breast rather than by hormones alone.

The thick, yellowish first milk made in late pregnancy and the first days after birth. It comes in small volumes but is concentrated in immunoglobulins, especially secretory IgA, protein, and minerals.

Release of milk from the alveoli when oxytocin makes myoepithelial cells contract. It can be triggered by suckling, infant crying, or thoughts of the baby, and may be blunted by stress or pain.

A protein in milk that builds up when milk is not removed and locally slows secretion in that breast. This autocrine mechanism lets each breast adjust output to how well it is drained.

A pituitary hormone released in response to nipple stimulation that promotes milk synthesis. Levels rise during feeding, and baseline levels are higher at night, which supports frequent night feeds.

Complex carbohydrates in human milk that the infant cannot digest. They nourish beneficial gut bacteria such as Bifidobacterium and help block pathogens from attaching to the intestinal lining.

The newborn's ability to alternate sucking, swallowing, and breathing in a stable rhythm. It matures over the first months and can be disrupted by prematurity, oral anomalies, or neurologic problems.

Early behavioral signals that an infant is ready to feed, such as rooting, hand-to-mouth movements, and stirring. Crying is a late cue and tends to make latching harder.

The small volume an infant's stomach holds in the first days, roughly 5 to 7 mL on day one and growing to about 45 to 60 mL by the end of the first week.

Placing a bare infant prone against a parent's bare chest. It helps stabilize temperature, breathing, and blood glucose, and it promotes early breastfeeding and bonding.

Onset of copious milk more than about 72 hours after birth. Risk factors include cesarean birth, prolonged labor, retained placenta, obesity, diabetes, and infrequent milk removal.

Painful overfilling of the breasts with milk, fluid, and blood in the days after birth. It can flatten the nipple and make latching difficult, and frequent milk removal relieves it.

A localized blockage of a milk duct that causes a tender lump in the breast, usually without fever. Frequent feeding, gentle massage, and varied positions help it resolve.

Inflammation of the breast, often with infection, producing pain, redness, and flu-like symptoms with fever. Continued milk removal and prompt treatment matter, and the milk remains safe for the baby.

A short, tight, or anteriorly attached lingual frenulum that restricts tongue movement. Effects on feeding vary widely, so assessment focuses on tongue function rather than appearance alone.

A breast condition in which milk-secreting tissue is underdeveloped, sometimes with widely spaced or tubular breasts. It can cause low supply that does not fully respond to more frequent feeding.

Abnormally low blood glucose in a newborn, seen more often in preterm infants, those small or large for gestational age, and infants of diabetic mothers. Early, frequent feeding is an important preventive measure.

Jaundice in the first week caused or worsened by insufficient milk intake, which slows bilirubin clearance through stool. It differs from breast-milk jaundice, which appears later and is benign.

The weight-adjusted amount of a maternal drug an infant receives through milk, expressed as a percentage of the maternal dose. Values under about 10 percent generally indicate low risk.

A substance or medication believed to increase milk production. Evidence is limited for most of them, and they work best when milk removal is already frequent and effective.

A dopamine antagonist sometimes prescribed off-label to raise milk supply. It carries risks of cardiac arrhythmia and QT prolongation, and its safety during breastfeeding is debated.

A dopamine antagonist antiemetic with a modest, short-lived milk-enhancing effect. It passes into milk and can cause maternal depression and sedation.

A parent's confidence in their ability to breastfeed successfully. Higher confidence predicts longer breastfeeding duration and is strengthened by mastery experiences and supportive feedback.

Feeding in response to an infant's cues rather than on a fixed schedule, letting the baby set the amount and pace. It supports intake self-regulation and is recommended for all infants.

A collaborative counseling style using open questions, affirmation, reflection, and summary to help parents voice their own reasons for change, rather than giving advice or applying pressure.

A technique in which the parent explains or demonstrates what they learned in their own words, allowing the clinician to check understanding and correct any misunderstanding.

An ongoing attitude of self-reflection and openness that acknowledges power differences and the limits of one's own cultural knowledge when caring for families from different backgrounds.

A World Health Organization resolution that restricts promotion of breast-milk substitutes, bottles, and teats in order to protect breastfeeding from commercial pressure.

A WHO and UNICEF program in which maternity facilities implement the Ten Steps to Successful Breastfeeding and meet standards on feeding support and Code compliance to earn designation.

Keeping the infant in the same room as the parent day and night instead of in a nursery. It increases breastfeeding frequency and duration and supports cue-based feeding.

A scored breastfeeding assessment covering latch, audible swallowing, nipple type, comfort, and hold or positioning. Each item scores zero to two, giving a total out of ten.

A feeding position in which the parent supports the infant's head and neck with the hand opposite the breast being used, giving control over head placement and latch.

Removing milk by compressing the breast with the fingers in a rhythmic pattern. It is useful for collecting colostrum, relieving engorgement, and when a pump is unavailable.

A thin silicone cap worn over the nipple during feeding, used short-term to help infants with latch difficulties. It needs monitoring because milk transfer may be reduced.

Weighing the infant before and after a feeding on a sensitive scale to estimate milk intake. Variability limits accuracy, so results are combined with serial weights and clinical signs.

The proportion of birth weight lost in the first days of life. A loss beyond about 7 to 10 percent calls for closer assessment of feeding effectiveness and hydration.

A procedure that releases a restrictive lingual frenulum. It is considered only after functional assessment and works best when paired with ongoing feeding support.

A technique of applying gentle pressure around the base of the nipple to push fluid backward, softening areolar edema so a very engorged breast can be latched.