Glossary

The tube leading to the smallest lobule of a compound gland; it is characterized by a narrow lumen.

American College of Nurse-Midwives.

American Congress of Obstetricians and Gynecologists.

American College of Osteopathic Pediatricians.

The collection of cells and cellular products that contribute to antigen recognition and cell differentiation into memory cells for subsequent encounters with the same antigen(s). The system is characterized by high antigen specificity and enhanced and accelerated immune response on reencountering the specific antigen(s).

See Panniculus adiposus .

Conducting inward to, or toward, the center of an organ, gland, or other structure or area. Applies to sensory nerves, arteries, and lymph vessels.

The Agency for Healthcare Research and Quality (AHRQ) is the lead federal agency charged with improving the safety and quality of America’s health care system. The AHRQ develops the knowledge, tools, and data needed to improve the health care system and help Americans, health care professionals, and policy makers make informed health decisions. It exists within the Department of Health and Human Services (DHHS).

Familial puerperal alactogenesis is a genetically transmitted, isolated prolactin deficiency.

The inappropriate and sometimes excessive response of the immune system to common antigens (allergens) in the environment. Examples of such allergens include foods (milk, egg, fish, nuts), pollen, dust mites, bee venom, etc.

Academy of Lactation Policy and Practice.

A glandular acinus or terminal portion of the alveolar gland, where milk is secreted and stored, that measures approximately 0.12 mm in diameter. From 10 to 100 alveoli, or tubulosaccular secretory units, make up a lobulus.

Congenital absence of the breast—breast tissue, areola, and nipple.

Congenital absence of breast tissue but with a nipple and areola.

Elastic portion of the duct, just proximal to the nipple, that expands as milk fills the breast.

A tight lingual frenulum (the membrane attaching the tongue to the bottom of the mouth). This condition is also referred to as tongue-tie . When the frenulum is tight, it can restrict the movement of the tongue, which on occasion can result in difficulty with breastfeeding for some mothers (nipple pain) and babies (poor latch and milk transfer).

A term descriptive of a gland cell that loses part of its protoplasmic substance in the process of excretion.

The occurrence of cell death without inflammation, as a programmed and controlled part of growth and development of an organ or organism.

A test, named after its developer, performed on fresh blood to distinguish between adult and fetal hemoglobin. The blood is suspended in saline, and an equal amount of 10% sodium hydroxide (NaOH) is added and mixed; adult hemoglobin turns brown, and fetal hemoglobin remains red. A control sample of known adult blood also should be tested for comparison.

Development of a branched arrangement or structure.

Areola. The pigmented area surrounding the papilla mammae, or nipple.

An artificial object used in place of and therefore often shaped like a mammary nipple used with a bottle to feed an infant formula or used by itself for an infant to suck on instead of a bottle or breast.

A breastfeeding position in which the baby is above the mother (or the mother is “down under” the baby), the reason for the name of the posture. The mother is supine while the infant is usually prone with its legs straddling one of the mother’s legs and the infant’s face aligned with the breast.

Autophagosome. A membrane-bound body within a cell containing degenerating cell organelles.

The amount of milk present in a breast that is removed by a suckling infant or expressed from the breast by hand or pump. This volume is the “storage” capacity of the breast in the interval between emptying the breast.

An international program of the World Health Organization and United Nations International Children’s Education Fund (UNICEF). The initiative is a global effort for improving the role of maternity services to enable mothers to successfully breastfeed their infants. Its main goals are improving the care of pregnant women, mothers, and newborns at any health facilities that provide maternity services and for protecting, promoting, and supporting breastfeeding, in alignment with the International Code of Marketing of Breastmilk Substitutes.

The concept that infants as young as 6 months can play a role in their own food intake. Infant behavior contributes to choosing the complementary foods, amounts of food, and timing or rhythm of eating, making weaning a gradual and manageable adjustment for both mother and infant.

Bronchus-associated immunocompetent lymphoid tissue, to which the mammary gland may act as an extension. See GALT and MALT .

The layer of material, 50 to 100 nm thick, that lies adjacent to the plasma membrane of the basal surfaces of epithelial cells. The basal lamina is visualized by electron microscopy. It contains collagen and certain carbohydrates. It is often called the basement membrane when visualized by light microscopy.

Gram-positive anaerobic bacteria found in breast milk and often common in the gastrointestinal tract (and stools) of breastfed infants. They ferment sugars (oligosaccharides) into fatty acids (acetate, butyrate, propionate). Human milk oligosaccharides (HMOs) are a readily used source of oligosaccharides.

A component of food characterized as nonnutritive. It exerts an effect on nutrition and health by a chemical or regulatory process. There are many bioactive components in human milk, some of which have both a nutritive and nonnutritive function.

A milk-filled, blocked nipple pore often manifesting as a white, yellow, or clear dot or blister on the nipple or areola.

A relative obstruction of a milk duct as a result of stasis or impaired drainage leading to a local swelling in the breast. The swelling can vary in size and shape from a small nodule to a large wedge-shaped area. It should be distinguished from engorgement, mastitis, and breast abscess and is not associated with systemic signs of inflammation.

Nursing on the same breast for two or more feedings without nursing or otherwise releasing milk from the other breast. This strategy is often used to decrease an overly abundant milk supply.

The act of feeding an infant through a bottle regardless of the liquid being fed.

A common term for mammary gland. The breast is rudimentary in males but evolves through developmental stages in females (embryogenesis, puberty, mammogenesis, pregnancy, lactogenesis/lactation, involution). The breast’s primary function is the synthesis and secretion of milk to feed an infant; it subsequently involutes to a quiescent period after weaning.

An inflammatory swelling within the breast with pain and swelling, often with redness, warmth, and fluctuance as it evolves to a fluid-filled mass. Systemic signs of inflammation occur in some instances. It should be distinguished from engorgement, a blocked duct and mastitis.

Refers to the innate behavior of a newborn infant after being placed on the mother’s abdomen (skin to skin or tummy to tummy), moving up to the mother’s breast, latching on, and suckling if unimpeded.

A fluid-filled mass within breast tissue. It is often characterized as smooth, firm, lobulated, and mobile. It should be distinguished from a galactocele (fluid within the mass is milk), abscess, tumor, or cancer.

The underdevelopment of the breast.

The manipulation of the breast in a pattern or technique of kneading or rubbing the breast. During lactation, it is often useful for relieving blocked ducts, stimulating secretion, or as a comfort measure.

A piece of equipment for removing milk from a breast. It can be manual or electric and usually removes the milk by suction.

When an infant does not attach to the breast and suckle well after a period of prior effective breastfeeding. The infant will turn its head away from the breast or side to side, arching its back, crying, and even flailing its arms as if avoiding the breast. This may be a temporary behavior or lead to weaning.

A plastic device worn to manage inverted nipples or protect damaged nipples. The breast side of the device surrounds the nipple, and the outer piece is often dome shaped to separate the nipple from the pressure of the bra or clothing.

One component of a breast pump. It is the funnel-shaped portion covering the areola and creating a tunnel that encircles the nipple, creating space for milk flow into the collection container.

The removal of milk from a breast by an infant suckling on the breast.

The action of an infant removing milk from a breast by sucking (nursing).

The various positions in which a mother holds herself and her infant to facilitate an effective latch and successful breastfeeding. A few of those positions include lying back, side-lying, cradle, cross-cradle, and football hold position.

The fluid produced in the mammary gland after the birth of an infant, during the period of lactation. Lactocytes produce this fluid as nutrition for the infant; composed of fats, carbohydrates, proteins, vitamins, nutrients, and biologically active components contributing to the growth, development, and maturation of the infant. Breast milk is usually specifically human milk, because the milk of other animals is not called breast milk. ( Colostrum, transitional breast milk , and mature breast milk are associated terms.)

The removal of milk from a breast. It occurs by a breast pump or hand expression.

When the infant is fed breast milk by some other manner besides directly removing it from the breast. The infant is fed breast milk by finger, cup, syringe, bottle, etc.

Any fluid or food produced and marketed to replace breast milk. The World Health Organization determines the relative nutritional suitability of such foods. Infant formula is the most recognized example of a breast milk substitute produced by modification of other animal milks or food sources (soy).

The active movement of human milk from the breast to the infant during a breastfeed.

Breastsleeping refers to bedsharing (mother and infant) along with breastfeeding. The term, coined by James McKenna and Lee Gettler, is meant to highlight the benefits of ongoing breastfeeding in combination with bed-sharing in the absence of known hazardous factors related to formula- or bottle-sharing and bedsharing.

A group of milk-specific proteins and derivatives of caseinogen, characterized by ester-bound phosphate, high-protein content, and low solubility. The fraction of milk protein that forms the curd in milk. The human caseins form a micellar structure, which facilitates the high availability of calcium in human milk compared with other animal caseins.

Carolina Global Breastfeeding Institute.

Certified lactation counselor. Breastfeeding care provider who has completed a course of study resulting in certification as a lactation counselor.

A continuum of birth defects resulting from incomplete fusion of tissue in the midline of the face during the normal embryonic process. Clefts vary as unilateral or bilateral and can be as mild as a small notch in the upper lip to the complete opening in the lip through the hard and soft palate into the nasal cavity.

Nursing privately at home, in secret, as a result of insensitive, uninformed relatives and friends and even health care providers.

A cycle of short, closely spaced feedings, usually in less than 30 minutes, interspersed with periods of rest or sleep.

The behavior of an infant characterized by recurrent and usually prolonged crying, fussiness, and irritability without an obvious cause. It is benign and self-resolving and is without an apparent easy solution. It most commonly occurs between 2 and 5 months of age. There is no known cause.

The first milk. This yellow, sticky fluid is secreted by the breast during the first few days postpartum and provides nutrition and protection against infectious disease with its high level of immune globulins. It contains more protein, less sugar, and much less fat than mature breast milk. It comes in small volumes, estimated at 30 mL in the first day.

A type of secretory cell in the shape of a hexagonal prism; it appears rectangular when sectioned across the long axis, the length being considerably greater than the width.

Triangular ligaments stretching between the mammary gland, the skin, the retinacula cutis, the pectineal ligament, and the chorda obliqua. These ligaments underlie and support the breasts.

The mammary gland; breast mass after freeing breast from deep attachments and removal of skin, subcutaneous connective tissue, and fat.

When a baby or young child sleeps close to one or both parents, as opposed to in a separate room. Usually, this means within an arm’s length of one another, but sometimes it is meant to imply sleeping in the same room.

Measurement for estimating the fat content and therefore the caloric content of a milk sample. A microhematocrit tube is filled with milk (usually a mix of foremilk and hind milk) and spun in a microcentrifuge for 15 min. The layer of fat is measured as a percentage, as one measures a blood hematocrit.

When a lactating woman breastfeeds a baby that is not her own, often temporarily, in the role of a childcare arrangement. A wet nurse is an old term for such a lactating woman who breastfeeds a child besides her own for some form of remuneration.

A secretory cell that has similar height and breadth measurements.

A generic term for small nonantibody proteins produced by a broad range of cells that are then involved in cell signaling without entering the cytoplasm. Cytokines include chemokines, interferons, interleukins, and lymphokines but not growth factors or hormones. They are an important part of the immune system.

Cell fluid.

The Department of Health and Human Services (DHHS) in the United States is a US governmental agency tasked with protecting the health of all Americans and providing human services.

Excess milk produced by lactating women and voluntarily donated to a milk bank for use for other infants besides their own. Mothers are screened for health and social risk factors (not dissimilar from blood donors), and the milk is processed and pasteurized before providing it to a recipient infant.

An individual who supports, interacts with, and aids the mother at any time within the period that includes pregnancy, birth, and lactation; this may be a relative, friend, or neighbor and is usually, but not necessarily, a woman. One who gives psychological encouragement and physical assistance to a new mother. These are lay individuals who train to assist the mother during labor and delivery.

An artificial nipple made of plastic, rubber, or silicone for use by an infant to suck in place of a breast or bottle. Its shape usually includes the “nipple” and a mouth shield and handle attached to prevent choking or swallowing of the nipple.

A social relationship between two individuals. The breastfeeding dyad refers to all that is involved in such a relationship between a mother and her breastfeeding infant.

The negative emotions and experience of a breastfeeding woman just before and during the stimulation of the milk ejection reflex. The dysphoric milk ejection reflex (D-MER) usually occurs suddenly and the mother is happy or without dysphoria between episodes.

Carrying impulses away from a nerve center.

A reflex initiated by the suckling of the infant at the breast, which triggers the pituitary gland to release oxytocin into the bloodstream. The oxytocin causes the myoepithelial cells to contract and eject the milk from the collecting ductules. Also called let-down reflex or draught .

The first stage of mammary development, beginning with the mammary band about the 35th embryonic day.

The swelling and distention of the breasts, usually in the early days of initiation of lactation, caused by vascular dilatation and the arrival of the early milk. This can occur normally in the first 2 to 3 days after birth. It may become a problem when the swelling increases, becomes firm or hard or painful with warmth and sometimes a low-grade fever. Obstruction of the breast lymphatics can lead to secondary edema. The treatment and prevention of engorgement is through the frequent and adequate drainage of milk from the breast.

The system through which lactogenic hormones or cytokines lead to the migration of lymphocytes from the intestine to the mammary glands. These transported lymphocytes produce secretory immunoglobulin A antibodies, which enter the breast milk and provide added protection of the infant to antigens in the mother and infant’s environs, which the mother was exposed to in her respiratory tree and intestine.

A term sometimes used to “quantify” the relative amount of breast milk an infant received. It is applied to an infant who has ever been put to the breast. That includes if the infant was put to the breast only once or 100 times, so it is a poor term and inaccurate quantification.

When an infant is fed only breast milk and no other foods or liquids. This means not even water. The breast milk can be by breastfeeding, expressed mother’s own milk, donor human milk, or milk from a wet nurse or milk sharing. Drops or syrups of vitamins, minerals, or medicines are “allowed.”

Breast milk removed by expression, although sometimes includes pumped breast milk.

Primary lactation failure caused by an isolated prolactin deficiency occurring genetically in families.

Stimulation of an infant’s tongue with a finger to initiate sucking. A feeding tube attached to a syringe of milk along the finger will provide milk to the infant when suckling is correct.

The first milk obtained at the onset of suckling or expression. It contains less fat than later milk of that same feeding (i.e., the hind milk).

The generic term for infant or artificial formula. It is a liquid food processed from other animal milks or plants (soy) as a substitute for human breast milk. The Codex Alimentarius maintains standards, guidelines, and codes of practice for preparation and content of infant formulas intended for use in infants under 1 year of age. Infant formula is made up of nutrients, micronutrients, vitamins, and minerals intended to support normal growth and development of infants.

A fold of mucous membrane extending from the floor of the mouth to the underside of the tongue. This anchors the tongue to the floor of the mouth in various degrees of tightness and/or limitation of the movement of the tongue.

A very simple procedure removing the frenulum. (Other procedures are frenectomy, frenotomy, and frenulectomy.)