Breastfeeding

Lactogenesis I and other changes in pregnancy

Changes in pregnancy, starting around 16 weeks gestational age, prepare the breast for lactation. These changes, collectively known as Lactogenesis I, are directed by hormones produced by the placenta and the brain, namely estrogen, progesterone, prolactin, which gradually increase throughout the pregnancy, and result in the structural development of the alveolar (milk-producing) tissue and the production of colostrum.^{[9]: 18–21 [22][23]} While prolactin is the predominant hormone in milk production, progesterone, which is at high levels during pregnancy, blocks the prolactin receptors in the breast, thus inhibiting milk from "coming in" during pregnancy.^{[9]: 18–21 [21][24]}

Many other physiologic changes occur under the control of progesterone and estrogen. These changes include, but are not limited to, dilation of blood vessels, increased blood flow to the uterus, increased availability of glucose (which subsequently is passed through the placenta to the fetus), and increased skin pigmentation, which results in darkening of the nipples and areola, formation of the linea nigra, and onset of melasma of pregnancy.^{[9]: 18–21 [25][26]}

Lactogenesis II

The third stage of labor describes the period between the birth of the baby and the delivery of the placenta, which normally lasts less than 30 minutes.^[27] The delivery of the placenta causes an abrupt drop off of placental hormones.^{[27][9]: 18–21 [24]} This drop, specifically in progesterone, allows prolactin to work effectively at its receptors in the breast, leading to an array of changes over the next several days that allow the milk to "come in"; these changes are known collectively as Lactogenesis II.^{[9]: 18–21 [24][28]} Colostrum continues to be produced for these next few days, as Lactogenesis II occurs.^{[9]: 18–21} Milk may "come in" as late as five days after delivery; however, this process may be delayed due to a number of factors as described in the Process "Delay in milk 'coming in'" subsection below.^{[9]: 18–21 [24]} Oxytocin, which signals the smooth muscle of the uterus to contract during pregnancy, labor, birth and following delivery, is also involved in the process of breastfeeding.^[27][24] Oxytocin also contracts the smooth muscle layer of band-like cells surrounding the milk ducts and alveoli to s the newly produced milk through the duct system and out through the nipple.^{[9]: 18–21 [24]} This process is known as the milk ejection reflex, or let-down.^{[9]: 18–21} Because of oxytocin's dual activity at the breast and the uterus, breastfeeding mothers may also experience uterine cramping at the time of breastfeeding, for the first several days to weeks.^[24]

Lactogenesis III

Prolactin and oxytocin are vital for establishing milk supply initially, however, once the milk supply is well established, the volume and content of the milk produced is controlled locally.^{[9]: 18–21 [21]} Although prolactin levels are higher on average among breastfeeding mothers, prolactin levels themselves do not correlate to milk volume.^{[9]: 18–21} At this stage, production of milk is triggered by milk drainage from the breasts. The only way to maintain milk supply is to drain the breasts frequently. Infrequent or incomplete drainage of the breasts, decreases blood flow to the alveoli and signals the milk-producing cells to produce less milk.^{[9]: 18–21 [21][24][9]: 72–80}

Nutritional content

The pattern of intended nutrient content in breast milk is relatively consistent. Breastmilk is made from nutrients in the mother's bloodstream and bodily stores. It has an optimal balance of fat, sugar, water, and protein that is needed for a baby's age appropriate growth and development.^{[9]: 10–14 [30]} That being said, a variety of factors can influence the nutritional makeup of breastmilk, including gestational age, age of infant, maternal age, maternal smoking, and nutritional needs of the infant.^{[9]: 10–14 [31]}

The first type of milk produced is called colostrum. The volume of colostrum produced during each feeding is appropriate for the size of the newborn stomach and is sufficient, calorically, for feeding a newborn during the first few days of life.^{[9]: 27–34 [32]} Produced during pregnancy and the first days after childbirth, colostrum is rich in protein and Vitamins A, B12 and K, which supports infants' growth, brain development, vision, immune systems, red blood cells, and clotting cascade.^{[33][34][35][36]} The breast milk also has long-chain polyunsaturated fatty acids which help with normal retinal and neural development.^[37] The caloric content of colostrum is about 54 Calories/100mL.^[38] The second type of milk is transitional milk, which is produced during the transition from colostrum to mature breast milk. As the breast milk matures over the course to several weeks, the protein content of the milk decreases on average.^{[9]: 10–14} The caloric content of breastmilk is reflective of the caloric requirements of the infant, increasing steadily after 12 months.^{[9]: 10–14} The caloric content of breastmilk in the first 12 months of breastfeeding is approximated to be 58-72 Calories/100mL. Comparatively, the caloric content after 48 months is approximately 83-129 Calories/100mL.^{[9]: 10–14}

When a mother has her full milk supply and is feeding her infant, the first milk to be expressed is called the foremilk. Foremilk is typically thinner and less rich in calories. The hindmilk that follows is rich in calories and fat.^[39]: 239

If the mother is not deficient in vitamins, breast milk normally supplies the baby's needs, with the exception of Vitamin D. The CDC, National Health Service (UK), Canadian Paediatric Society, the American Academy of Pediatrics, and the American Academy of Family Physicians all agree that breast milk alone does not provide infants with an adequate amount of Vitamin D, thus they advise parents to supplement their infants with 400 IU Vitamin D daily.^{[40][41][42][43][44][45]} Providing this quantity of Vitamin D to breastfeeding infants has been shown to reduce rates of Vitamin D insufficiency (defined as 25-OH vitamin D < 50 nmol/L). However, there was insufficient evidence in the most recent Cochrane Review, to determine if this quantity reduced rates of Vitamin D deficiency (defined as 25-OH vitamin D < 30 nmol/L) or rickets.^[46] Term infants typically do not need iron supplementation. Delaying clamping of the cord at birth for at least one minute improves the infants' iron status for the first year.^{[9]: 50–51 [47]} When complementary (solid) foods are introduced at about 6 months of age, parents should make sure to choose iron-rich foods to help maintain their children's iron stores.^{[9]: 50–51 [47]}

Bioactive content

In addition to the nutritional benefits of breastmilk, breast milk also provides enzymes, antibodies, and other substances that support the infant's growth and development.^{[9]: 10–14} The bioactive makeup of breastmilk also changes based on the needs of the infant; for example, when an infant is recovering from an upper respiratory infection, local signaling allows for increased passage of immune cells and proteins to aid the infant's immune system.^{[9]: 10–14 [48]}

Produced during pregnancy and the first days after childbirth, colostrum is easy to digest and has laxative properties that help the infant to pass early stools.^{[9]: 27–34 [34]} This aids in the excretion of excess bilirubin, which helps to prevent jaundice.^{[9]: 34–47} Colostrum also helps to seal the infants gastrointestinal tract from foreign substances and germs, which may sensitize the baby to foods that the mother has eaten and decrease the risk of diarrheal illness.^{[9]: 10–14 [24]} Although the baby has received some antibodies (IgG) through the placenta, colostrum contains a substance which is new to the newborn, secretory immunoglobulin A (IgA). IgA works to attack germs in the mucous membranes of the throat, lungs, and intestines, which are most likely to come under attack from germs.^{[9]: 10–14 [24][49]} Additionally, colostrum and mature breast milk contain many antioxidant and anti-inflammatory enzymes and proteins that decrease the risk of gastrointestinal allergies to food, respiratory allergies to air particles like pollen, and other atopic diseases, such as asthma and eczema.^{[9]: 10–14 [24]}

Commencement

It is recommended for mothers to initiate breastfeeding within the first hour after birth.^{[27][9]: 27–34 [50][51][52]} Uninterrupted skin-to-skin contact and breastfeeding can begin immediately after birth, and should continue for at least one hour after birth.^{[9]: 27–34 [52]} This period of infant-mother interaction, known generally as kangaroo care, or the "golden hour" during the immediate postpartum period, assists in the mother–child bonding for both mother and baby, and is thought to encourage instinctual breastfeeding behavior in the infant.^{[9]: 27–34 [53]} Newborns who are immediately placed on their mother's skin have a natural instinct to latch on to the breast and start nursing, typically within one hour of birth. Success with breastfeeding in this "golden hour" increases the likelihood of successful breastfeeding at discharge.^{[9]: 27–34}

Skin-to-skin mother-baby contact should still occur, even if the baby is born by Cesarean surgery.^{[9]: 27–34 [54]} The baby is placed on the mother in the operating room or the recovery area. If the mother is unable to immediately hold the baby a family member can provide skin-to-skin care until the mother is able.

Timing

Newborn babies usually breastfeed 8 to 12 times every 24 hours, and they typically express hunger cues every one to three hours for the first two to four weeks of their lives.^{[27][9]: 27–34 [9]: 50–51 [60]} A newborn has a small stomach capacity, approximately 20 ml.^[61] The amount of breast milk that is produced is timed to meet the infant's needs in that the first milk, colostrum, is concentrated but produced in only very small amounts, gradually increasing in volume to meet the expanding size of the infant's stomach capacity.^{[9]: 27–34 [49]}

Many newborns will typically feed for 10 to 15 minutes on each breast, however feeds may last up to 45 minutes depending on infant wakefulness and efficiency.^{[9]: 50–51 [62]}

It is important for parents to recognize the difference between Nutritive and Non-Nutritive Sucking. Nutritive Sucking follows a slow, rhythmic pattern, with 1–2 sucks per swallow. Non-nutritive sucking is a faster-paced sucking pattern with few swallows. This swallow pattern is often observed at the beginning and/or the end of a feed. At the beginning of the feed, this pattern triggers milk letdown, while at the end of the feed, this may be a signal of the infant tired or becoming relaxed with a slower milk velocity.^{[9]: 27–34}

Duration and exclusivity

Numerous health organizations, including, but not limited to, the CDC, WHO, National Health Service, Canadian Pediatric Society, American Academy of Pediatrics, and American Academy of Family Physicians, recommend breastfeeding exclusively for six months following birth, unless medically contraindicated.^{[3][9]: 15–17 [63][64][65][66][4][67][68][69][70][71][72]} Exclusive breastfeeding is defined as "an infant's consumption of human milk with no supplementation of any type (no water, no juice, no nonhuman milk and no foods) except for vitamins, minerals and medications."^{[9]: 15–17 [56]} Supplementation with human donor breastmilk may be indicated in some specific cases, as discussed below.^[73] After solids are introduced at around six months of age, continued breastfeeding is recommended. The American Academy of Pediatrics recommends that babies be breastfed at least until 12 months, or longer if both the mother and child wish.^{[9]: 15–17 [4]} The World Health Organization's guidelines recommend "continue[d] frequent, on-demand breastfeeding until two years of age or beyond.^[50][74]

Extended breastfeeding means breastfeeding after the age of 12 or 24 months, depending on the source. In Western countries such as the United States, Canada, and Great Britain, extended breastfeeding is relatively uncommon and can provoke criticism.^[75][76]

In the United States, 22.4% of babies are breastfed for 12 months, the minimum amount of time advised by the American Academy of Pediatrics. In India, mothers commonly breastfeed for 2 to 3 years.^[77]

Position

Effective positioning and technique for latching on are necessary to prevent nipple soreness and allow the baby to obtain enough milk.^{[9]: 27–34 [9]: 50–51 [80]}

Babies can successfully latch on to the breast from multiple positions. Each baby may prefer a particular position. The "football" hold places the baby's legs next to the mother's side with the baby facing the mother. Using the "cradle" or "cross-body" hold, the mother supports the baby's head in the crook of her arm. The "cross-over" hold is similar to the cradle hold, except that the mother supports the baby's head with the opposite hand. The mother may choose a reclining position on her back or side with the baby lying next to her.^[81]

No matter the position the parent-infant dyad finds most comfortable, there are a few components of every position which will help facilitate a successful latch. One key component is maternal comfort. The mother should be comfortable while breastfeeding, and should have her back, feet, and arms supported with pillows as necessary. Additionally, when starting the latch process, the infant should be aligned with their abdomen facing their mother, which can be remembered as "tummy-to-mummy," and with their hips, shoulders and head aligned. This alignment helps to facilitate proper, efficient swallowing mechanics.^{[9]: 27–34}

• 
  Standing mother breastfeeding her baby, Canjambari, Guinea-Bissau, 1973
• 
  Breastfeeding – Cradle hold.
• 
  Breastfeeding – Cross cradle position.
• 
  Breastfeeding – Football hold.
• 
  Breastfeeding – Semi-reclining position.
• 
  Breastfeeding – Side-lying position.
• 
  Breastfeeding – Supine position.
• 
  Breastfeeding – Twins, cross cradle position I.
• 
  Breastfeeding – Twins, football or clutch hold.
• 
  Breastfeeding – Twins, parallel position II.

Latching

Latching refers to how the baby fastens onto the breast while feeding.

Making use of anatomy and reflexes

Sebaceous glands called Glands of Montgomery located in the areola secrete an oily fluid that lubricate and protect the nipple during latching. The visible portions of the glands can be seen on the skin's surface as small round bumps.^{[9]: 18–21} The rooting reflex is the baby's natural tendency to turn towards the breast with the mouth open wide.^[83] When preparing to latch, mothers should make use of this reflex by gently stroking the baby's philtrum, the area between the upper lip and the nose, with their nipple to induce the baby to open their mouth with a wide gape.^[82] One way to help the infant achieve a deep latch is to compress the breast tissue into a "U" or "hamburger shape," so that the infant can fit the breast tissue into their mouth. This is done by the mother placing her thumb and fingers in line with the infant's nose and mouth respectively and using this grip to compress the breast tissue.^[82]

Signs of a poor, shallow latch

In a poor, shallow latch, the infant latches close to or at the nipple, causing the mother intense pain during latching that is relieved with infant release from the breast.^[89] While the infant is at the breast, the first indicators of a shallow latch are having the areola be largely visible outside the infant's mouth and a narrow infant mouth angle.^[84] Additional signs result from poor positioning when the infant comes toward the breast to latch. If the infant leads with their brow or forehead, they are likely to flex their neck; this mechanism of latching causes the nipple to point down and then hit the hard palate during sucking.^[89] From an external view, this manifests as the nose and forehead being close to the breast and the chin far from the breast.^[84] This neck flexion also obstructs the normal swallowing mechanism, preventing the infant from drinking efficiently.^[84] In addition to not being able to swallow properly, this shallow latch prevents the infant from adequately compressing the glandular tissue behind the nipple and stimulating milk flow; thus, they may begin to apply more suction, which manifests externally as cheek dimpling, or sucking their cheeks in.^{[9]: 27–34 [84]}

Let-down reflex

When the baby suckles muscles in the breast squeeze milk towards the nipples. This is called the let-down reflex. Some women report that they do not experience anything while others report a tingling feeling which is sometimes described as quite strong. The baby may be seen to respond to the beginning of the flow of milk by changing from quick sucks to deep rhythmic swallows. Sometimes the let-down is so strong that the baby splutters and coughs and the mother may need to remove the baby from her breast for a short time until the flow becomes less forceful. Milk may also let-down unexpectedly when a mother hears her baby cry or even only thinks about the baby. Nursing pads may be made or purchased to absorb unexpected milk flows.^[90][91]

Problems with breastfeeding

Use of pacifiers

The World Health Organization's Ten Steps to Successful Breastfeeding recommends total avoidance of pacifiers for breastfeeding infants. In 2016 a large review of studies reported that the use of a pacifier beginning at birth or after lactation was established did not significantly affect the duration of exclusive and partial breastfeeding up to four months of age. The CDC, however, currently (2022) reports that early use of pacifiers can have a negative outcome on the success of breastfeeding and they suggest that it should be delayed until breastfeeding is firmly established.^[94][95][96]

Engorgement

Main article: Breast engorgement

Engorgement is the swelling and stretching of the breast tissue due to accumulation of fluid in the tissue surrounding and supporting the milk-producing cells and ducts.^{[9]: 55 [16]} Engorgement most frequently occurs as milk "comes in" and during the weaning process.^{[9]: 55 [106]} As milk is coming in, several processes occur. At the end of pregnancy there is dilation of the blood vessels which supply the breast, allowing for leaking into the tissue or interstitial space.^[16] Additionally, the birth of an infant is followed by massive fluid shifts to both offload excess fluid, which had been used to supply oxygen and nutrients to the fetus through the placenta, which is no longer needed, and supply additional fluid to the breasts in order to start the process of making milk. These fluid shifts often result in some of this excess fluid leaking into the breast tissue.^[9]: 55 Finally, milk "coming in" can create an uncomfortably full feeling, which combined with the aforementioned fluid accumulation in the breast tissue, can cause severe pain.^{[16][9]: 55} If breastfeeding is suddenly stopped, the breasts are likely to become engorged. Pumping small amounts to relieve discomfort helps to gradually train the breasts to produce less milk. There is presently no safe medication to prevent engorgement, but cold compresses and ibuprofen may help to relieve pain and swelling. Pain should go away with emptying of the breasts. If symptoms continue and comfort measures are not helpful, it is possible a blocked milk duct or infection may be present and seek medical intervention.^[107]

Weaning

Weaning is the process of replacing breast milk with other foods; the infant is fully weaned after the replacement is complete.^{[9]: 112–116 [9]} Psychological factors affect the weaning process for both mother and infant, as issues of closeness and separation are very prominent.^[113] Unless a medical emergency necessitates abruptly stopping breastfeeding, it is best to gradually increase the period between feedings and/or eliminate feedings to allow the breasts to adjust to the decreased demands without becoming engorged.^[9] Studies show that a large number of women discontinue breastfeeding early due to lack of working place support for breastfeeding mothers.^[114] La Leche League advises parents to shift their children's focus at bedtime away from breastfeeding, as it is often the most difficult feeding for them to let go.^[115]

If weaning is begun at 12 months or later it is not necessary to switch to infant formula or "toddler formula" as is sold commercially. At 12 months it is recommended that the baby be switched to whole cow's milk. Reduced-fat or skim milk generally is not appropriate before age 2 because it does not have enough fat or calories to promote early brain development.^[116]

If the mother was experiencing lactational amenorrhea, periods will begin to return with weaning, along with restored fertility.^[117]

Extended breastfeeding

Extended breastfeeding usually means breastfeeding beyond the age of 12 to 24 months, depending on the culture. The American Academy of Family Physicians states that "health outcomes for mothers and babies are best when breastfeeding continues for at least two years.^[118] The American Academy of Pediatrics recommends that mothers nurse for the first 12 months and "thereafter for as long as mother and baby desire." The World Health Organization recommends breastfeeding up to age 2 "or beyond."^[114]

Breast milk is known to contain lactoferrin (Lf), which protects the infant from infection caused by a wide range of pathogens. The amount of Lf in breast milk is lactation-stage related. One study looked at Lf concentration in prolonged lactation from the first to the 48th month postpartum. It was found to be at the highest level in colostrum, dropped to the lowest level during 1 – 12 months of lactation, and then increased significantly during the 13–24 months of lactation, close to the Lf concentration in colostrum. At over 24 months the level dropped, though not significantly.^[119]

Professional breastfeeding support

Lactation consultants are trained to assist mothers in preventing and solving breastfeeding difficulties such as sore nipples and low milk supply. They commonly work in hospitals, physician or midwife practices, public health programs, and private practice. Lactation consultants earn their credential, International Board Certified Lactation Consultant (IBCLC), through the International Board of Lactation Consultant Examiners.^{[120][121][122][123]}

Breastfeeding support from a lactation consultant is associated with higher rates of any breastfeeding at 6 months but not at 1 month or 3 months post pregnancy based on a meta-analysis of studies conducted in the US and Canada.^[124] Peer support for breastfeeding has been found to be associated with higher rates of any breastfeeding at 1 month and 3 to 6 months and of exclusive breastfeeding at 1 month, but it is unrelated to breastfeeding outcomes past 6 months post pregnancy.^[124]

Maternal contraindications

Medical conditions that do not allow breastfeeding are fairly rare.^[4] Infants that are otherwise healthy uniformly benefit from breastfeeding,^[125] however, extra precautions should be taken or breastfeeding avoided in circumstances including certain infectious diseases and medical conditions.

Maternal infections

HIV

A breastfeeding child can become infected with HIV. Factors such as the mother's viral load complicate breastfeeding recommendations for HIV-positive mothers. The World Health Organization highlights the possibility of breastfeeding in mothers on anti-viral therapy and with undetectable viral loads, especially in areas where access to clean water is poor and where death from infectious diseases is common, citing low transmission rates when the mother is on anti-viral therapy.^{[3][126][127]} They also recommend that national authorities in each country decide which infant feeding practice should be promoted by their maternal and child health services to best avoid HIV transmission from mother to child.^[128] However, the CDC continues to recommend against HIV-positive mothers breastfeeding in the United States.^[127][129] Infant formula should only be given if this can be safely done.^[3]

Human T-lymphotropic virus (types I and II)

Human T-Lymphotrophic Virus (HTLV) is able to be passed through breastmilk from mother to child.^{[9]: 15–17 [130]} The worldwide rate of transmission through breastmilk is estimated to be 3.9–27%, and this risk is increased by high maternal viral load and prolonged periods of breastfeeding.^[131][132] Current data demonstrates that while breastfeeding for less than six months does not, independently, increase risk of HTLV-1 transmission, not breastfeeding during that time does decrease risk of transmission.^[133] As such, CDC recommends against breastfeeding when mothers have HTLV Types I or II.^{[9]: 15–17 [134]} Recognizing the importance of breastfeeding in more resource-poor areas of the world, the World Health Organization recommends shortening the duration of breastfeeding, or avoiding breastfeeding where possible.^[131]

Hemorrhagic viral disease (Marburg virus, Ebola)

Mothers with Marburg virus or Ebola should not breastfeed their infants or feed them with expressed breastmilk.^{[135][39]: 738–753}

Tuberculosis

Infants whose mothers have suspected untreated tuberculosis (TB) should be isolated from their mothers to reduce risk of transmission. As such, these infants should not be breastfed during this time and until the mother has been treated appropriately for 2 weeks and is no longer contagious.^{[135][39]: 411–313 [136]} However, these infants may be fed expressed breastmilk from their mother.^{[135][39]: 411–313 [136]} Transmission of TB through breastmilk, without an isolated breast infection caused by the Tuberculosis bacteria (Mycobacterium tuberculosis), has never been documented in the scientific literature.^{[39]: 411–313} Mothers who do have an isolated breast infection caused by Mycobacterium tuberculosis, termed tuberculous mastitis, should not feed their infants with their own breastmilk, even if it is fed by bottle.^{[39]: 411–313}

Herpes simplex

Herpes simplex virus (HSV) is the virus that causes genital herpes and oral cold sores, and it can be very dangerous to infants.^[137] The CDC advises to continue breastfeeding if there are no open/active lesions on the breast and other lesions covered.^[137]

Herpes zoster (chickenpox and shingles)

Varicella zoster is the virus responsible for chickenpox and shingles (also known as herpes zoster).^[138] The CDC advises that breastfeeding is safe to continue as long as the breasts are clear of lesions, also emphasizing that if pumping or hand expressing milk, proper hand-hygiene should be used to minimize transfer.^{[9]: 15–17 [138]}

COVID-19 (no contraindication)

In May 2020, WHO and UNICEF stressed that the ongoing COVID-19 pandemic was not a reason to discontinue breastfeeding. They recommend that women should continue to breastfeed during the pandemic even if they have confirmed or suspected COVID-19 because evidence indicates that it is not likely that COVID-19 can be transmitted through breast milk.^[139] A study published in 2021 found that, while SARS-CoV-2 RNA may be found in some samples of breastmilk from recently infected mothers, the breastmilk does not contain infectious virus and is not considered a transmission risk factor.^[140] Mothers who have suspected or confirmed diagnoses of COVID-19 should thoroughly wash their hands and wear a well-fitting mask prior to breastfeeding their infant, or express breastmilk and feed the infant by bottle.^[141]

Infantile contraindications

Expressed milk

A mother may express milk (remove milk from breasts) for storage and later use. Expression may occur manually with hand expression, or by using a breast pump.^{[39]: 220 [158]}

Mothers express milk for multiple reasons. Expressing breast milk can maintain a mother's milk supply when mother and child are apart. A sick baby who is unable to nurse can take expressed milk through a nasogastric tube. Some babies are unable or unwilling to nurse. Maternal breastmilk is the food of choice for premature babies; these infants may be fed maternal milk through tubes, supplemental nursing systems, bottles, spoons or cups until they develop satisfactory ability to suck and swallow breast milk.^{[39]: 502–545} Some women donate expressed breast milk (EBM) to others, either directly or through a milk bank. This allows mothers who cannot breastfeed to give their baby the benefits of breast milk. While informally-shared breastmilk does carry the nutritional benefits of breastmilk, this breastmilk is most often not pasteurized or screened, and thus carries with it the risk of transmitting diseases or medications that are unsafe for infants.^[159] Parents considering directed or informal milk sharing should discuss this option with their doctor, and they should be familiar with the donors medical history and milk handling practices.^[159] Use of informally-shared (unscreened, not pasteurized) milk from an anonymous donor is discouraged by the Academy of Breastfeeding Medicine.^[159]

Babies feed differently with artificial nipples than from a breast. With the breast, the infant's tongue massages the milk out rather than sucking, and the nipple does not go as far into the mouth. Drinking from a bottle takes less effort and the milk may come more rapidly, potentially causing the baby to lose desire for the breast. This is often referred to as nipple confusion or nipple preference.^[39]: 241 While some infants do experience this preference for the bottle, many infants do not and will be able to alternate between bottle and breast without issue.^[39]: 241

"Exclusively expressing" and "exclusively pumping" are terms for a mother who exclusively feeds a baby expressed milk. Exclusively pumping is poorly studied in the literature, especially in recent years. However, from available evidence, it appears to be fairly uncommon, with only approximately 7% of study participants reporting exclusive pumping.^[160]

Shared nursing

It is not only a mother who may breastfeed a child. Parents may hire another person to do so (a wet nurse), or may share childcare with another mother (cross-nursing). Both of these were common throughout history. It remains popular in some developing nations, including those in Africa, for more than one woman to breastfeed a child. Shared breastfeeding is a risk factor for HIV infection in infants.^[163] Shared nursing can sometimes provoke negative social reactions in the English-speaking world.^[164][165]

Tandem nursing

It is possible for a mother to continue breastfeeding an older sibling while also breastfeeding a new baby; this is called tandem nursing. During the late stages of pregnancy, the milk changes to colostrum. While some children continue to breastfeed even with this change, others may wean. Most mothers can produce enough milk for tandem nursing, but the new baby should be nursed first for at least the first few days after delivery to ensure that it receives enough colostrum.^[166]

Breastfeeding triplets or larger broods is a challenge given babies' varying appetites. Breasts can respond to the demand and produce larger milk quantities; mothers have breastfed triplets successfully.^{[167][168][169]}

• 
  Newborn twins being breastfed
• 
  Woman breastfeeds 2 year old twins whilst reading them a book.
• 
  Woman tandem nurses an infant and a toddler.

Re-lactation and induced lactation

Re-lactation is the process of restarting breastfeeding.^[170] In developing countries, mothers may restart breastfeeding after a weaning as part of an oral rehydration treatment for diarrhea. In developed countries, re-lactation is common after early medical problems are resolved, or because a mother changes her mind about breastfeeding.

Re-lactation is most easily accomplished with a newborn or with a baby that was previously breastfeeding; if the baby was initially bottle-fed, the baby may refuse to suckle. If the mother has recently stopped breastfeeding, chances are higher that the milk supply will return and be adequate. Although some mothers successfully re-lactate after months-long interruptions, success is higher for shorter interruptions.^[170]

Techniques to promote lactation use frequent attempts to breastfeed, extensive skin-to-skin contact with the baby, and frequent, long pumping sessions.^[170] Suckling may be encouraged with a tube filled with infant formula, so that the baby associates suckling at the breast with food. A dropper or syringe without the needle may be used to place milk onto the breast while the baby suckles. The mother should allow the infant to suckle at least ten times during 24 hours, and more times if the baby is interested. These times can include every two hours, whenever the baby seems interested, longer at each breast, and when the baby is sleepy when they might suckle more readily. In keeping with increasing contact between mother and child, including increasing skin-to-skin contact, grandmothers should pull back and help in other ways. Later on, grandmothers can again provide more direct care for the infant.^[171]

These techniques require the mother's commitment over a period of weeks or months. However, even when lactation is established, the supply may not be large enough to breastfeed exclusively. A supportive social environment improves the likelihood of success.^[170] As the mother's milk production increases, other feeding can decrease. Parents and other family members should watch the baby's weight gain and urine output to assess nutritional adequacy.^[171]

A WHO manual for physicians and senior health workers citing a 1992 source states: "If a baby has been breastfeeding sometimes, the breastmilk supply increases in a few days. If a baby has stopped breastfeeding, it may take 1–2 weeks or more before much breastmilk comes."^[171]

Induced lactation, also called adoptive lactation, is the process of starting breastfeeding in a woman who did not give birth.^[170] This usually requires the adoptive mother to take hormones and other drugs to stimulate breast development and promote milk production. In some cultures, breastfeeding an adoptive child creates milk kinship that builds community bonds across class and other hierarchal bonds.^[170]

Baby

Early breastfeeding is associated with fewer nighttime feeding problems.^[175] Early skin-to-skin contact between mother and baby improves breastfeeding outcomes and increases cardio-respiratory stability.^[176] Some studies show that breastfeeding aids general health, growth and development in the infant. Infants who are not breastfed are at mildly increased risk of developing acute and chronic diseases, including lower respiratory infection, ear infections, bacteremia, bacterial meningitis, botulism, urinary tract infection and necrotizing enterocolitis.^[177][178] Breastfeeding may protect against sudden infant death syndrome,^[179] insulin-dependent diabetes mellitus, Crohn's disease, ulcerative colitis, childhood lymphoma, allergic diseases, digestive diseases,^[56] obesity, or childhood leukemia later in life.^[180] and may enhance cognitive development.^[56][181] The CDC reports that infants who are breastfed have reduced risks of ear infections, obesity, type 1 diabetes, asthma, SIDS, and lower respiratory, and gastrointestinal infections.^[182] It is hard however to distinguish the importance of breastfeeding per se and other correlated socioeconomic factors (breastfeeding is more frequent in richer families with higher educations). Comparing breastfed and non-breastfed siblings in a given family drastically decreases the association between breastfeeding and long-term child well-being.^[37]

Mother

Social support

A review found that when effective forms of support are offered to women, exclusive breastfeeding and duration of breastfeeding are increased. Characteristics of effective support includes ongoing, face-to-face support tailored to fit their needs. It may be offered by lay/peer supporters, professional supporters, or a combination of both.^[231] This review contrasts with another large review that looked at education programs alone, which found no conclusive evidence of initiation of breastfeeding or the proportion of women breastfeeding either exclusively or partially at 3 months and 6 months.^[232]

Positive social support in essential relationships of new mothers plays a central role in the promotion of breastfeeding outside of the confines of medical centers. Social support can come in many incarnations, including tangible, affectionate, social interaction, and emotional and informational support. An increase in these capacities of support has shown to greatly positively effect breastfeeding rates, especially among women with education below a high school level.^[233] Some mothers that have used lactation rooms have taken to leaving sticky notes to not only thank the businesses that have provided them but to support, encourage, and praise the nursing moms who use them.^[234]

In the social circles surrounding the mother, support is most crucial from the male partner, the mother's mother, and her family and friends.^[235] Research has shown that the closest relationships to the mother have the strongest impact on breastfeeding rates, while negative perspectives on breastfeeding from close relatives hinder its prevalence.^[233]

• Mother – Adolescence is a risk factor for low breastfeeding rates, although classes, books and personal counseling (professional or lay) can help compensate.^[236] Some women fear that breastfeeding will negatively impact the look of their breasts. However, a 2008 study found that breastfeeding had no effect on the breasts; other factors did contribute to "drooping" of the breasts, such as advanced age, number of pregnancies and smoking behavior.^[237]
• Partner – Partners may lack knowledge of breastfeeding and their role in the practice.
• Wet nursing – Social and cultural attitudes towards breastfeeding in the African-American community are also influenced by the legacy of forced wet-nursing during slavery.^[238]

Healthcare

Ethnicity and socioeconomic status

The rates of breastfeeding in the African-American community remain much lower than any other race, for a variety of proposed reasons. These include the legacy of wet nursing during slavery, higher rates of poor perinatal health, higher stress levels, less access to support, and less flexibility in the workplace.^[259] While for other races as socio-economic class raises rates of breastfeeding also go up, for the African-American community breastfeeding rates remain consistently low regardless of socio-economic class.^[260]

There are also racial disparities in access to maternity care practices that support breastfeeding. In the US, primarily African-American neighborhoods are more likely to have facilities (such as hospitals and female healthcare clinics) that do not support breastfeeding, contributing to the low rate of breastfeeding in the African-American community. Comparing facilities in primarily African American neighborhoods to ones in primarily European-American neighborhoods, the rates of practices that support or discourage breastfeeding were: limited use of supplements (13.1% compared with 25.8%) and rooming-in (27.7–39.4%)^[261]

Low-income mothers are more likely to have unintended pregnancies.^[262] Mothers whose pregnancies are unintended are less likely to breastfeed.^[263]

Especially the combination of powdered formula with unclean water can be very harmful to the health of babies. In the late 1970s, there was a boycott against Nestle due to the great number of baby deaths due to formula. Dr. Michele Barry explains that breastfeeding is most imperative in poverty environments due to the lack of access of clean water for the formula. A Lancet study in 2016 found that universal breastfeeding would prevent the deaths of 800,000 children as well as save $300,000,000.^[264]

Social acceptance

Some women feel discomfort when breastfeeding in public.^[265] Public breastfeeding may be forbidden in some places, not addressed by law in others, and a legal right in others. Even given a legal right, some mothers are reluctant to breastfeed,^[266][267] while others may object to the practice.^[268]

The use of infant formula was thought to be a way for western culture to adapt to negative perceptions of breastfeeding.^[269] The breast pump offered a way for mothers to supply breast milk with most of formula feeding's convenience and without enduring possible disapproval of nursing.^[270] Some may object to breastfeeding because of the implicit association between infant feeding and sex.^[271] These negative cultural connotations may reduce breastfeeding duration.^{[266][272][273][274]} Maternal guilt and shame is often affected by how a mother feeds an infant. These emotions occur in both bottle- and breast- feeding mothers, although for different reasons. Bottle feeding mothers may feel that they should be breastfeeding.^[275] Conversely, breastfeeding mothers may feel forced to feed in uncomfortable circumstances. Some may see breastfeeding as, "indecent, disgusting, animalistic, sexual, and even possibly a perverse act."^[276] Advocates (known by the neologism "lactivists") use "nurse-ins" to show support for breastfeeding in public.^[265] One study that approached the subject from a feminist viewpoint suggested that both nursing and non-nursing mothers often feel maternal guilt and shame with formula feeding mothers feeling that they are not living up to the ideals of motherhood and nursing mothers concerned that they are transgressing "cultural expectations regarding feminine modesty." The authors advocate that women be provided with education on breastfeeding's benefits as well as problem-solving skills,^[275] however there is no conclusive evidence that breastfeeding education alone improves initiation of breastfeeding or the proportion of women breastfeeding either exclusively or partially at 3 months and 6 months.^[232]

Location

The examples and perspective in this section deal primarily with the United States and the United Kingdom and do not represent a worldwide view of the subject. (December 2024)

In the United States, all fifty states, along with the District of Columbia, Puerto Rico and the U.S. Virgin Islands, have laws that allow a mother to breastfeed a baby in any public or private location.^[277] In that country, the Friendly Airports for Mothers (FAM) Act was signed into law in 2019, and the requirements went into effects in 2021. This law requires that all large and medium hub airports in the U.S. provide a private, non-bathroom lactation space in each terminal building.^[278]

Some commercial establishments in the U.S. provide breastfeeding rooms, although laws generally specify that mothers may breastfeed anywhere without requiring a special area. Despite these laws, many women in the United States continue to be publicly shamed or asked to refrain from breastfeeding in public.^[279] In the United Kingdom, the Equality Act 2010 makes the prevention of breastfeeding in any public place discrimination under the law.^[280] In Scotland, it is a criminal offense for one to attempt to prevent another from feeding a child under 24 months in public.^[280]

While laws in the U.S. were passed in 2010 which required that nursing mothers who had returned to work be given a non-bathroom space to express milk and a reasonable break time to do so, as of 2016 the majority of American women still did not have access to both accommodations.^[281]

In 2014, newly elected Pope Francis drew worldwide commentary when he encouraged mothers to breastfeed babies in church. During a papal baptism, he said that mothers "should not stand on ceremony" if their children were hungry. "If they are hungry, mothers, feed them, without thinking twice," he said, smiling. "Because they are the most important people here."^[282]

Financial considerations

Breastfeeding is less costly than alternatives, but the mother generally must eat more food than would otherwise be necessary. In the US, the extra money spent on food (about US $17 each week) is usually about half as much money as the cost of infant formula.^[11] According to the CDC, breastfeeding mothers need an extra 450 to 500 calories per day compared to their pre-pregnancy caloric intake.^[291]

Breastfeeding reduces health care costs and the cost of caring for sick babies. Parents of breastfed babies are less likely to miss work and lose income because their babies are sick.^[11] Looking at three of the most common infant illnesses, lower respiratory tract illnesses, otitis media, and gastrointestinal illness, one study compared infants that had been exclusively breastfed for at least three months to those who had not. It found that in the first year of life there were 2033 excess office visits, 212 excess days of hospitalization, and 609 excess prescriptions for these three illnesses per 1000 never-breastfed infants compared with 1000 infants exclusively breastfed for at least 3 months.^[292][293] However, in a study of over 140,000 newborns in the first month of life, exclusively breastfed newborns had higher hospital readmission rates than those exclusively formula fed, and those exclusively breastfed also had more neonatal outpatient visits compared to those exclusively formula fed.^[294]

Criticism of breastfeeding advocacy

There are controversies and ethical considerations surrounding the means used by public campaigns which attempt to increase breastfeeding rates, relating to pressure put on women, and potential feeling of guilt and shame of women who fail to breastfeed; and social condemnation of women who use formula.^{[296][297][298][299]} In addition to this, there is also the moral question as to what degree the state or medical community can interfere with a person's self-determination: for example in the United Arab Emirates the law requires women to breastfeed babies for at least 2 years and allows husbands to sue them if they do not.^[300][301]

It is widely assumed that if women's healthcare providers encourage them to breastfeed, those who choose not to will experience more guilt. Evidence does not support this assumption. On the contrary, a study on the effects of prenatal breastfeeding counselling found that those who had received such counselling and chosen to formula-feed denied experiencing feelings of guilt. Women were equally comfortable with their subsequent choices for feeding their infant regardless of whether they had received encouragement to breastfeed.^[302]

Preventing a situation where women are denied agency and/or stigmatized for formula use is also seen as important. In 2018, in the UK, a policy statement from the Royal College of Midwives said that women should be supported and not stigmatized, if after being given advice and information, they choose to formula feed.^[303]

Social marketing

Social marketing is a marketing approach intended to change people's behavior to benefit both individuals and society.^[304] When applied to breastfeeding promotion, social marketing works to provide positive messages and images of breastfeeding to increase visibility. Social marketing in the context of breastfeeding has shown efficacy in media campaigns.^{[305][306][307][308][309][310]} Some oppose the marketing of infant formula, especially in developing countries. They are concerned that mothers who use formula will stop breastfeeding and become dependent upon substitutes that are unaffordable or less safe.^[311][312] Through efforts including the Nestlé boycott, they have advocated for bans on free samples of infant formula and for the adoption of pro-breastfeeding codes such as the International Code of Marketing of Breast-milk Substitutes by the World Health Assembly in 1981 and the Innocenti Declaration by WHO and UNICEF policy-makers in August 1990.^[311] Additionally, formula companies have spent millions internationally on campaigns to promote the use of formula as an alternative to mother's milk.^[313] Giving out gift bags that contain infant formula to women as they leave the hospital is also a marketing strategy. The U.S. Government Accountability Office has reported that women who receive formula samples at discharge are associated with lower breastfeeding rates than those who did not receive gift bags.^[314]

Baby Friendly Hospital Initiative

The Baby Friendly Hospital Initiative (BFHI) is a program launched by the World Health Organization (WHO) in conjunction with UNICEF in order to promote infant feeding and maternal bonding through certified hospitals and birthing centers. BFHI was developed as a response to the influence held by formula companies in private and public maternal health care. The initiative has two core tenets: the Ten Steps to Successful Breastfeeding and the International Code of Marketing of Breast-milk Substitutes.^[315] The BFHI has especially targeted hospitals and birthing centers in the developing world, as these facilities are most at risk to the detrimental effects of reduced breastfeeding rates. As of 2018, 530 hospitals in the United States hold the "Baby-Friendly" title in all 50 states. Globally, there are more than 20,000 "Baby-Friendly" hospitals worldwide in over 150 countries.^[316]

Representation on television

The first depiction of breastfeeding on television was in the children's program Sesame Street, in 1977.^[317] With few exceptions since that time, breastfeeding on television has either been portrayed as strange, disgusting, or a source of comedy, or it has been omitted entirely in favor of bottle feeding.^[317]

Religion

In some cultures, people who have been breastfed by the same woman are milk-siblings who are equal in legal and social standing to a consanguineous sibling.^[318] Islam has a complex system of rules regarding this, known as Rada (fiqh). Like the Christian practice of godparenting, milk kinship established a second family that could take responsibility for a child whose biological parents came to harm. "Milk kinship in Islam thus appears to be a culturally distinctive, but by no means unique, institutional form of adoptive kinship."^[319]

In Western countries, differences in breastfeeding practices have also been observed according to the affiliation or practice of Christian religions; unaffiliated and Protestant women exhibit higher rates of breastfeeding.^{[320][321][322][323]}