MIDW246: Breast Anatomy & Breastfeeding

What is sIgA in breastmilk? What is its function?

sIgA (Secretory Immunoglobulin A) is an antibody that is synthesized and stored in the breast during lactation. It provides active immunity in immediate replacement of IgG (the immunoglobulin passively passed to baby via the placenta in utero). sIgA coats mucosal surfaces to prevent adherence and penetration by pathogens.

During the first 24 hours, what volume of colostrum does the average baby consume per breastfeed?

approx. 10ml

The percentage of infants having ANY breastmilk in Australia at six months is?

approx. 50%. Exclusively breastfed is only 15%!

When are fat levels in breastmilk at their momentary highest?

Fat levels in breastmilk are highest when the breast is relatively empty. Fat levels are NOT highest when the milk ejection reflex is strong, whether the woman eats a high-fat diet, or during the night.

What is mammary (glandular) tissue composed of?

1. Lactocytes - milk-producing cells on the mammary epithelial layer (inside layer of gland). 2. Myoepithelial cells - smooth muscle cells on the outside of the gland which contract to squeeze ready milk out into the duct. Responsible for the letdown reflex! 3. Lactiferous (milk) ducts - ducts that converge and form a branched system, down which milk is drawn, connecting the clusters of glandular lobules to the nipple.

Where in the brain is PROLACTIN secreted from?

ANTERIOR pituitary gland.

Which lymph nodes collect most of the lymph drainage from the lactating breasts?

axillary nodes

What is reverse pressure softening?

'Reverse pressure softening' is a technique to relieve engorgement. The aim is to push fluid in the tissue under the nipple and areola further back into the breast, to relieve the pressure. To do this, apply pressure with two or three fingers of each hand placed flat at the sides of and close to your nipple, and hold for 1-3 minutes. Or use all fingertips of one hand around the nipple and push in, holding for 1-3 minutes, until the tissue softens.

How does the breast change across pregnancy and before birth?

* Breast growth — Pregnancy brings increased growth within the breast. The size of the breast varies greatly depending on the amount of fatty tissue present within the breast. (Breast size bears no relationship to the amount of milk produced. The rare exception is a condition called insufficient glandular development of the breast.) * Mammogenesis: Glandular tissue and duct development — By the time the baby is born, glandular tissue will have replaced most of the fatty tissue. Across second and third trimesters, continued development and enlargement of the duct system occur, plus additional lobule growth. * Nipple changes — the Montgomery glands may become enlarged and elevated, and the nipples may become more pronounced. Darkening of the areola serves to act as a visual target for the newborn. * COLOSTRUM — Under the influence of a 10- to 20-fold increase in placental lactogen, colostrum appears near the end of the second trimester. (The breast will produce colostrum if the fetus is born any time from 16 weeks.)

How can women prevent engorgement? (4 ways)

* Feed baby FREQUENTLY from birth. * Don't limit baby's time at the breast. UNLIMITED ACCESS * Wake baby for a feed if her breasts become full and uncomfortable (especially at night time). * Ensure baby is positioned and attached correctly, to maximise the amount of milk she is getting.

What is the role of prolactin in long-term lactation + breastfeeding?

* Receptor development: Frequent feeding in the first days postpartum also increases the number of prolactin receptor sites within the breast, which play a role in breastmilk production long term (rather than relying on serum levels of prolactin). These prolactin receptors are laid down in the first 3 months postpartum and allow abundant milk production to continue when total baseline prolactin levels drop over the first 3 to 4 months. * Higher during sleep: Prolactin levels naturally rise in sleep states and so breastfeeding at night helps maintain an elevated baseline prolactin level. Mothers may be reassured that feeding their baby frequently overnight is both meeting their baby's needs and ensuring an adequate milk supply! * Fertility suppressing: Frequent prolactin release also inhibits fertility hormones — follicle-stimulating hormone (FSH) and luteinizing hormone (LH) — causing lactational amenorrhea and preventing the return of fertility.

How can women relieve engorgement?

* Take your bra off completely before beginning to breastfeed. * Gentle breast massage or use of warmth for up to a few minutes before feeds may help trigger your let-down reflex. * If your baby has trouble attaching to your breast, use 'reverse pressure softening' to soften the breast tissue under your areola or express some milk (by hand or with a pump). * Feed your baby frequently. * Massage the breast gently while you are feeding. * If necessary, express for comfort after feeds. * Use cold packs or chilled, washed, cabbage leaves after a feed to reduce inflammation. * Ask your medical adviser or hospital staff about taking anti-inflammatory medication or pain relief if needed. NOTE Expressing with a breast pump is only suggested in the case of severe engorgement. Education in anticipation of breast engorgement should be given to all breastfeeding mothers prior to hospital discharge.

What benefits does a high frequency of feeding have (irrespective of milk volume) for breastfeeding women?

*Strong correlation between more feeding and lower rates of severe hyperbilirubinemia (jaundice) *Milk production higher for women who breastfed more often * Engorgement reduces in occurrence and severity. * More opportunities to learn baby and observe baby. More chance to practice and build maternal confidence!

What is the % protein content of mature breast milk?

*Whey: 80% of protein content in beginning. This is because whey is growth-enhancing and structural, but also protection against bacteria. It then decreases to 60% and eventually 50%. * Casein: 20% initially, then 40% of the protein in mature breast milk. This slowly increases to 50% by late lactation - this increase causes firmer, less stools by 3 or 4mo.

What are your priorities when helping a woman with breastfeeding on day one?

,

If a woman approaches saying she doesn't have enough milk (baby unsettled at/after breast), what is your approach? (9 points)

- Discuss where her concerns stem from. - Observe a feed for position, latch, comfort, baby's behaviours. - Assess baby's output/ask about baby's nappies. Educate about these. - Observe baby's general behaviour/cues of satiation and educate about these. Discussion points: 1. Worrying is common: Many women worry about not having 'enough' milk for their babies. 2. Wide variation of 'normal': Conclusions of research find exclusively breastfed babies (1- to 6-month-olds) consume between 0 to 240 g of milk, between 6 and 18 times, during 24 hours. 3. Overnight feeding is normal: 64% of infants breastfeeding 1 to 3 times at night. 4. NORMAL NAPPIES education! Provide her with the visual and practice observing baby's output over 24 hours. Nappies alone can be the comfort women need to know they are producing enough. 5. Sustained fat intake: Despite fat content of breast milk varying between breastfeeds and between mothers (22.3-61.6 g/L), the amount of fat consumed by the infant is independent of the frequency of breastfeeding. 6. Supply increases according to frequent feeding/emptying: If baby is hungry and breastfeeds vigorously (cluster/marathon feeding), leaving the breast relatively empty, production speeds up. Each breast makes milk slowly or quickly depending on how full or empty it is. Therefore, when the mother's breast seems emptiest, it is making milk the fastest. Baby's appetite controls mother's milk production - also known as 'demand feeding' or "feeding according to need". This information can be a comfort and reassurance to a mother whose baby is feeding frequently in the evenings. 7. Breasts don't have to completely empty every time: On average, 67% of the available milk is consumed at each breastfeeding. 8. Breastfeeding works with all different breast types: Each breast has its own individualised maximum storage capacity, which is not related to breast size. Mothers with greater storage capacity (the difference between maximum and minimum breast volumes in 24-hour period) simply have greater flexibility in feeding intervals. Women with smaller storage capacity can produce more than adequate volumes of breastmilk for their babies, they just have to breastfeed more often. Also, the right breast usually produces significantly more milk than the left. 9. Demand feeding - breastfed infants should be encouraged to feed on demand, day and night, according to their individual needs rather than conform to an 'average' that may not be appropriate for the individual mother-infant dyad. Strict scheduling does not make sense for baby or mother's ongoing milk supply.

Poor breastfeeding positioning and attachment is associated with (causes) which three things?

- Engorgement (of milk, not venous engorgement/oedema) - Nipple trauma - Low milk supply

What three hormonal events trigger Lactogenesis 2 to begin?

1. The withdrawal of progesterone with the birth of the placenta 2. High levels of prolactin 3. High levels of oxytocin ____________________________________________ The birth of the placenta triggers a cascade of hormonal effects. These are: 1. * LOWERED PROGESTERONE. The inhibitory effect of progesterone (released by placenta) is removed 2. * INCREASED PROLACTIN. Prolactin is then released by the anterior pituitary gland (because progesterone's inhibitory effect is removed) — to prepare for milk production and influence lactose synthesis 3. * INCREASED OXYTOCIN. Oxytocin is released by the posterior pituitary gland — this activates the myoepithelial cells surrounding alveoli in mammary glands, thus initiating the letdown reflex

What three things can the midwife suggest to women to manage lactation suppression after a perinatal death?

1. Wear a supportive bra 2. Using cool / cold packs or compresses to relieve discomfort 3. Take simple analgesia if needed

The main 4 maternal hormonal influences that affect breastfeeding are?

1. progesterone lowered 2. oestrogen lowered 3. prolactin rising 4. release of oxytocin rising ...the production of breastmilk also requires several other hormones for milk synthesis at the alveolar level: insulin, cortisol, thyroid, parathyroid, and growth hormone.

The number of ductal openings in the maternal nipple are?

4-18 per breast

What is the average normal milk volume per day by the end of the first week after birth?

500ml/day

What is the % water content for colostrum and mature milk?

87% for both.

What is the initiation rate of breastfeeding in Australia?

96% approx.

How does the degree to which medications bind with plasma proteins in the mother's circulation effect the drug level in breastmilk?

A drug that is HIGHLY bound to plasma proteins is LESS likely to enter breastmilk.

What advice do you give to a woman who's transitional milk has just 'come in' about protecting ongoing supply?

After the milk "comes in" it is still vital that the baby is fed frequently and according to need. - Women may feel like they have enough milk to feed 50 babies at this point! - The first two weeks have been described as a "launchpad" for ongoing breastmilk supply. - The colostrum elements of the breastmilk need to be completely emptied from the breast to maximise ongoing supply - this is assured with good positioning and attachment, and a baby doing her job to vigorously empty the breast. - Care should be taken with expressing to enthusiastically build supply. Formula use should be minimised and ceased as soon as possible. - Breastfeeding according to need is the BEST way to protect supply.

What is transitional milk? How can a woman tell if her milk is transitional?

As colostrum volumes increase over the first days, this breastmilk is often referred to as "transitional" because it contains many of the protective elements of colostrum as well as some features of mature milk. Transitional milk is often days 3-9, then becomes mature milk. How to tell if your milk is transitional: - Change in baby's feeding may include hearing their baby gulp milk during feeds and more pauses in the feed as the baby swallows. - Also, a feeling that breasts are "filling" or becoming heavier. - It has been noted that the milk of mothers with premature babies tends to contain features of colostrum for longer - in reflection of the increased immunological vulnerability of these babies.

When are Prolactin levels at their highest in the breastfeeding woman?

At night! They are not highest before a breastfeed, or immediately after birth.

What are bifido-bacteria and lactation-acid bacteria in breastmilk? What is their function?

Bifido-bacteria and lactation-acid bacteria are probiotics. These improve digestion and create a more acidic digestive tract (lower pH) which protects from infection. By contrast, formula makes a more alkaline environment.

What is Cholecystokinin (CCK)? Why is it important?

CCK is the digestive hormone in breast milk that helps baby absorb fat, feel satiated and sleep well. CCK peaks after feeding so may help to hold baby for 30min before putting them down. CCK increases with skin to skin and kangaroo care.

What are the reasons that Australian women most commonly give for stopping breastfeeding?

Central mediators of breastfeeding duration and top reasons for ceasing to breastfeed in Australia: 1. Poor attachment - concerns regarding breast trauma 2. Milk supply - "not enough breastmilk for the baby", 3. An unsettled baby - levels of infant satiety

What is the difference in fat content of colostrum versus mature milk?

Colostrum has 2-3g/100ml of fat. Mature breastmilk has 4-5g/100ml of fat (almost double). Fat in mature milk is 2-5% of its total volume.

What are named stages of milk transition after birth?

Colostrum is for first 3-5 days Transitional milk over next two weeks Mature milk from two weeks onward.

What is colostrum (its contents and amount) and what is its function?

Colostrum is initially produced in small volumes and is the perfect food for newborn babies, who have limited metabolic and gastro-intestinal capacity to utilise large volumes of any kind of milk, and who are acutely in need of protection. Contents: It is a mixture of residual cells in the breast and the first, newly formed milk. It is also rich in antibodies that protect the newborn. It is thick and yellow to orange in colour due to high levels of beta-carotene. It has higher concentrations of sodium, potassium, chloride, protein, fat-soluble vitamins, and minerals than mature milk. Function: Colostrum nourishes and protects the newborn. It also has an important laxative effect on the infant bowel that assists in the emptying of meconium. This is important because the retention of meconium may contribute to neonatal jaundice due to reabsorption of its bilirubin content. Amount: Babies get only a small amount of colostrum at each feed (approx 10ml per feed), but this matches what the baby's stomach (size of a marble at birth) is comfortably able to contain. Mothers produce widely varying amounts of colostrum (from 7 mL to 123 ml in the first 24 hours!!). Newborns are also likely to take widely varying volumes during breastfeeds. Many women will need reassurance that they have sufficient breastmilk for their baby in the first days.

What is the difference in nutrient contents of colostrum, mature milk, and later lactation milk?

Colostrum: - Has 2.5 times more protein than mature milk - colostrum is very high in whey protein. - Has lower fat content than mature milk (nearly half), - Lower energy and lactose then mature milk. Late lactation: - Zinc levels are lower later in lactation (with older babies) - Immune components in breast milk decrease over time as babies mature - but Lysozymes (enzymes in tears, saliva, sweat, and other body fluids which are bacteri-acidal and anti-inflammatory) continue to rise after 6mo.

What is engorgement? What causes it?

Engorgement (milk and venous) is caused by a build-up of milk, blood and other oedematous fluids in the breast tissue. Breast engorgement often occurs when feeding in the first days are infrequent and/or of limited duration. Women may find their breasts become larger and feel heavy, warmer and uncomfortable when their milk 'comes in', usually about 2-6 days after your baby is born. Engorgement is different from breast fullness alone. The process of painful engorgement is: 1. Increased blood flow to the breasts causes tissue congestion 2. The ducts and alveoli thus become constrained 3. Oedema develops secondary to swelling and obstruction of the lymphatic drainage system. 4. Oedema in the breasts means that the nipple may become flattened/taut and not protrude as normal. It can be painful for the mother and difficult for the baby to latch correctly.

What are the current recommendations of the World Health Organisation (WHO) in relation to breastfeeding?

Exclusive breastfeeding for around the first six months of life, with continued breastfeeding to 2 years and beyond with appropriate complementary foods.

How common is breastfeeding in Australia? How long do Australian women breastfeed for on average?

Exclusive breastfeeding is recommended by the WHO and Australia's NHMRC until the baby is around six months old. However, most women in Australia who breastfeed will also use formula after the first 1-2 weeks, and ONLY 15% of babies are breastfed to 5 months. - 96% of mothers initiate breastfeeding. Thereafter, exclusive breastfeeding rates drop off. - Less than half (39%) of babies are still being exclusively breastfed to 3 months (less than 4 months) - less than one quarter (15%) to 5 months (less than 6 months). - at 12 months, 28% of children were still being breastfed - at 18 months, 9% of children - at 24 months, 5% were still being breastfed.

What is the % fat content of mature breast milk?

Fat is 2-5% of the total milk volume. This varies from woman to woman and day to day. Fat levels are highest in the evening, and higher near end of feeding (hindmilk). Mature milk fat content near doubles from colostrum.

How does the breast change post-lactation (weaning)?

Following lactation, the breasts involute (i.e., the mammary gland returns to its nonproductive state of milk secretion). If milk is not removed (or minimally removed) from the breasts, as during weaning, the glands become distended. This interferes to some degree with the blood supply to the breasts, and milk production ceases. There is also evidence that an enzyme (FIL) produced by the unremoved milk decreases production. Milk remaining in the alveoli is gradually reabsorbed, and the alveoli collapse or rupture. Initially, after weaning, the breasts may appear smaller than their pre-pregnancy size. This is due to the reduced adipose tissue within the lactating breast. The adipose tissue gradually increases and the breast returns to its original adult state.

Advice for breastfeeding women whose baby suddenly slows/plateaus in weight gain?

Have there been any changes in your baby's behaviour? For example, has your baby been taking fewer feeds as a result of sleeping longer at night? Have you been trying to feed at set times instead of when the baby indicates? Have you (the mother) been stressed or unwell? For some women, this can cause a temporary dip in supply. Have you just started a new medication such as the contraceptive pill? Could you be pregnant? These factors can cause a dip in your supply. Has your baby been ill? Even a small cold can disrupt feeding and weight gain for a week or two. Has your baby previously gained well and is now slowing down normally? It is very normal for an exclusively breastfed baby's weight gain to slow down at 3-4 months. The World Health Organisation child growth standards, based on healthy breastfed babies, help demonstrate this. In most cases of sudden weight change, a 'wait-and-see' approach is justified if your baby seems happy and the other indicators of growth and health are fine. If there seems to be a temporary low supply problem, offering a couple of extra breastfeeds a day can help avoid a more serious situation. If you are concerned, talk to a HCP.

What prevents lactogenesis I proceeding into lactogenesis II before birth?

High circulating levels of progesterone and oestrogen is what keeps progression into Lactogenesis 2 at bay. The breasts are "quiescent but poised (ready)".

What are some symptoms of an oversupply of milk? What is the management plan for the woman?

If you keep making too much milk after the early weeks, you might have an over-supply of milk. Symptoms: - You might have rapidly-filling breasts between feeds - breastmilk might leak from your nipples between feeds - You might also have a fast letdown reflex. If you have a fast letdown you might notice that your baby often gags or gulps at the start of the feed and might come off the breast coughing. - A baby whose mother has an over-supply often has more wet and dirty nappies than usual, a lot of unsettled behaviour and large weight gains. - Baby might also spit up quite a bit of milk after feeds. Risks: If you have an over-supply you have a higher risk of a blocked duct or mastitis. Management: If you think you might have an over-supply call the Australian Breastfeeding Association Helpline on 1800 686 268 or talk to a lactation consultant. It is important to identify an oversupply properly so that it can be managed whilst protecting breastfeeding.

What is the role of oxytocin during pregnancy and in initiating lactation?

In pregnancy: Oxytocin receptor sites in the breast gradually increase up to 10-fold in pregnancy, as well as receptor sites in the uterus. The number of oxytocin receptor sites in the uterus also increase dramatically in pregnancy — this is so the uterus takes up more oxytocin in order to cause contractions, thereby facilitating birth and preventing postpartum haemorrhage. The uterus oxytocin receptor sites then dramatically decrease after birth. After birth: Oxytocin's role after birth is to cause milk ejection. This is the hormone responsible for the milk ejection response and the letdown reflex. How: The nipple becomes more sensitive to tactile stimulation in the 24 hours following birth. Stretch receptors in the nipple stimulate the release of oxytocin. Working together: Thus while prolactin is essential for initiating and maintaining lactation, oxytocin's function is to make the breastmilk available to the baby.

What can interfere with the letdown reflex?

In the early days of breastfeeding, it may take a number of minutes for the first letdown to occur. The letdown reflex may be interfered with by pain, stress, fatigue and anxiety.

What allows prolactin to enter breasts after birth?

In the first three days after delivery, oestrogen, progesterone, and hPL drop. Also, there are wide gaps in alveolar cells which allows prolactin to enter.

When judging the suitability of a medication for a breastfeeding mother, what things are important to consider about her situation?

It is important to consider: - The volume of breastmilk being consumed by the baby - How frequently the baby is being breastfed - The maturity and age of the baby ... These considerations are more important than whether there has been testing of the drug done on breastfeeding mothers.

What is the definition of lactation?

Lactation is the cyclical process of milk synthesis and secretion. Process: When the infant suckles, a series of events takes place within the mother's body. Stimulation of the nipple and areola sends signals to the mammary gland, which are then relayed to the central nervous system.

Which constituent of human breastmilk is most responsible for anti-inflammatory activity?

Lactoferrin - this is the second most abundant protein in breastmilk, found in whey protein. It has a multifaceted role in the immunity of an infant: - Prevents infection (has a direct antibiotic effect on harmful bacteria such as staphylococci and E. coli) - Plays a role in iron metabolism (lactoferrin binds with iron and deactivates pathogens that try to bind with iron, thereby neutralising unwanted gut flora) - Is anti-inflammatory - Is an antioxidant.

What happens in Lactogenesis 1? When does it occur and how?

Lactogenesis 1 is when colostrum begins to be produced. The mammary gland is now sufficiently formed and differentiated to secrete milk (secretory differentiation). When: Lactogenesis 1 occurs at around 16 weeks. (You may note in your practice that even women who birth babies prior to 24 weeks will produce colostrum and transition to Lactogenesis 2.) Note: Women may or may not leak colostrum through their pregnancy and this is not necessarily a reflection of presence or absence of colostrum or of post-birth volumes. Cause: High circulating levels of progesterone and oestrogen is what keeps progression into Lactogenesis 2 at bay. The breasts are "quiescent but poised (ready)".

When does Lactogenesis 2 usually begin (the 'milk coming in')?

Lactogenesis 2 begins usually at 40 hours post-birth, regardless of the volume of colostrum the woman has produced. It may initially go unnoticed by the mother. It may be delayed 10-20 hours if the mother has GDM.

What happens in Lactogenesis 2?

Lactogenesis 2 is defined as 'the milk coming in', or the time of copious milk secretion. - Secretory activation - Signs: It is marked by increases in blood flow to the breasts, increased oxygen and glucose requirements as well as sharply increased concentrations of citrate in the breast. When: This is greatly varied — usually between 40-60 hours post-birth, but can occur any time between 24 to 102 hours post-birth. There is significant variation for this event between women and even between their different babies. Cause: Lactogenesis 2 commences with the sudden withdrawal of progesterone when the placenta separates and is born. Reduced oestrogen levels and constant prolactin levels also trigger it. - Endocrine to autocrine: In Lactogenesis 2, milk production is initially under endocrine control. Continued production of milk gradually becomes governed by the infant — the breasts will begin to produce milk independent of infant suckling and the hormones this activates (prolactin). Thus the transitioning to autocrine control.

What is the definition of Lactogenesis?

Lactogenesis is the two-step process through which the mammary gland develops the capacity to secrete milk. It encompasses all the processes necessary to transform the gland from the undifferentiated state of early pregnancy, to a fully differentiated state after pregnancy. It is this differentiated second state (lactogenesis II) that allows full lactation (i.e., activates the process of milk production).

What is the function of lactose in breast milk?

Lactose is the primary carbohydrate in human milk. - It is a sugar that provides energy, particularly for the brain, cognitive development and CNS, but also for body growth. - Lactose intolerance doesn't occur in newborns

What is lactose overload? How is it caused? What are its symptoms?

Lactose overload can occur when baby is only getting foremilk. May cause frothy stools and possible failure to thrive. To prevent, try to keep baby on one side until finished to fully empty the breast before switching to the other side. This way baby gets plenty of fat-rich hindmilk too.

What is breastmilk lipase?

Lipase is a digestive enzyme (protein) in breast milk that helps an infant break down fat.

What component of human breastmilk is responsible for higher cognitive development and vision?

Long-chain (Omega 3) fatty acids

Four main stages of lactation and their timing are?

Mammogenesis - the process of growth and development of the mammary glands. breasts get larger and heavier. - starts in embryo, then accelerated at puberty Lactogenesis 1 - Colostrum (mid-pregnancy, from 16 weeks to end of pregnancy ) - secretory differentiation (myoepothelial cells in the alveoli differentiate into secretory cells) - under Endocrine control - progesterone inhibits prolactin at this time so Lactogenesis II is held off until birth Lactogenesis 2 - Transitional milk (the onset of more copious milk) - occurs approx 60 hours after birth of placenta (which is withdrawal of progesterone) - secretory activation - Endocrine control (suckling simulates letdown reflex via prolactin = increases prolactin receptor sites = higher production capacity of the breast) Lactogenesis 3 aka galactopoesis - mature breast milk (10 to 14 days post birth onwards) - Autocrine control (cyclical stimulation and draining of the breast is the primary catalyst for milk synthesis, instead of endocrine hormone reliant. The prolactin receptor sites are autonomous)

Define mammogenesis?

Mammogenesis is the process of growth and development of the mammary gland in preparation for milk production. This process begins when the mammary gland is exposed to oestrogen at puberty, and is completed during the third trimester of pregnancy. In addition to its effect on the mammary cells themselves, oestrogen stimulates the synthesis and release of prolactin. Rising prolactin levels appear to be necessary for oestrogen to exert its biologic effects on the mammary gland.

What is mature milk, and its two types?

Mature milk becomes predominant by around day 9. Mature milk supplies everything that baby needs longterm, including water. - Mature milk is 90% water, and the remaining 10% is carbohydrates, proteins, and fats (necessary for growth and energy). - There are particular advantages to babies receiving only their mother's mature breastmilk for the first six months of life. Research has demonstrated that the nature of breastmilk changes throughout a single breastfeed. It has two different components called foremilk and hindmilk. - Foremilk is found at the beginning of the feed; it contains water, vitamins, and protein. It can be thought of as the thirst-quenching part of the breastfeed for the baby. - Hindmilk is available after the baby has been suckling for some time and contains higher levels of fat, which satiate the baby and assist in weight gain. The more relatively empty the breast is, the higher the fat content of the milk, and the more stimulation there is to produce milk.

What is FIL? What is its role in galactopoiesis?

Milk contains a small whey protein called Feedback Inhibitor of Lactation (FIL). The role of FIL is to slow milk synthesis when the breast is full. Thus milk production slows when milk accumulates in the breast (because more FIL is present), and speeds up when the breast is emptier (and less FIL is present). The transition to autocrine control of milk production (galactopoiesis/ Lactogenesis III) involves the gradual activation of the mechanisms for the Feedback Inhibitor of Lactation (FIL). With this, prolactin levels gradually decrease with no impact on milk production.

Describe the compatibility of the most common medications used in the postnatal period with breastfeeding. Why is it important more women know about medication compatibilities?

Most drugs transfer to the infant via breastmilk in varying quantities, but most drugs are safe due to the quantity being too small to elicit a reaction. Maternal morbidity is common, with women experiencing short and long term issues following childbirth. It is the responsibility of the midwife to educate women about their health and to encourage women to seek help about the long term health problems they may experience. Some women do not seek help as they are not willing to take medication if they are breastfeeding. The majority of new mothers in Australia will initiate breastfeeding, adding complexity to prescribing of medication in the postpartum period.

What is the definition of the term exclusive breastfeeding?

No liquid or solid enters the infant's mouth other than breastmilk

What is the definition of Galactopoiesis ('Lactogenesis 3')? When does it occur?

Once Lactogenesis 2 has happened, continued production of milk is governed and guided by the infant. The process transitions to autocrine from endocrine function. It is defined by when milk removal from the breasts becomes the barometer for moderating breastmilk supply - milk production matches the infant's needs, and 'settles down' into a rhythm. Prolactin levels gradually decrease with no impact on milk production. Autocrine: Systems that are necessary to maintain the milk supply include the neuroendocrine (i.e., intact neurohormonal pathways and suckling) and autocrine (milk removal). In galactopoiesis, as the breastmilk supply is established, the autocrine system takes control of supply. When: Varies from occurring approximately 10 -14 days to 4-6 weeks postpartum.

What is the let-down (milk ejection) reflex? What are the steps of hormonal interactions that cause it to occur?

Oxytocin's role after birth is to cause the letdown reflex. This is the hormone responsible for the milk ejection response. How does letdown happen? - Oxytocin, like prolactin, is released in pulses. Oxytocin release is triggered by two things: 1) stimulation/stretching off the nipple, and/or 2) the mother thinking about feeding her baby or hearing a baby cry. (The first pulse often begins with 2), before the baby is put to the breast.) - Oxytocin then acts on the smooth muscle of each alveolus, causing it to contract, which triggers milk ejection. Contraction of the alveoli actively pushes the milk into the lactiferous ducts toward the nipple and finally to the infant. As the baby continues to suckle, additional milk ejection responses occur triggered by nipple stimulation. (Often the initial letdown pulse is the only one a woman can 'feel').

Where in the brain is OXYTOCIN secreted from?

POSTERIOR pituitary gland.

What is the primary cause of nipple pain during a breastfeed?

Poor positioning /attachment. This causes friction on the nipples during a feed caused by them rubbing on the hard palette roof of the baby's mouth.

What are the composition differences between preterm milk and term milk?

Preterm milk has: More energy- nucleotides and nitrogen More SIgA and other anti-infective properties 30% more fat More sodium, chloride, and iron

What is the role of progesterone during pregnancy and then in initiating lactation?

Progesterone acts as an antagonist to prolactin (receptor site blocker). In pregnancy, it therefore enables the prolactin level to rise without subsequent milk production. After birth of the placenta, pregnancy hormones progesterone (and oestrogen) suddenly drop. The elevated (and unblocked) prolactin level, in addition to the presence of insulin and cortisol, stimulates the milk supply to begin. How: Progesterone does this specifically by interfering with prolactin's activity on the cell receptor sites in the alveoli of the breast.

Which key hormone does NOT impact on mammogenesis during pregnancy?

Progesterone does NOT impact on mammogenesis during PREGNANCY. Prolactin, placental lactogen, and oestrogen DO.

What is the role of prolactin during pregnancy?

Prolactin is the main hormone involved in the formation and production of milk. It is secreted from the anterior pituitary gland. Role during pregnancy: Prolactin is associated with oestrogen. The high levels of circulating oestrogen during pregnancy cause a parallel increase in the circulating levels of prolactin. Together this helps to complete lobular development in the breasts, preparing them for lactation. (Progesterone is the antagonist that holds off full Lactogenesis 2 until after birth.)

How much milk do women produce, on average, per day at 2 weeks?

Range of 750-1200mls!

The breast's three main components - glandular tissue, fibrous tissue and adipose tissue - can change in relative proportions to each other according to what events? In what circumstance do these proportions/ratio never change?

Ratio of glandular, fibrous and fatty tissue in the breast can change depending on maternal age, menstrual cycle, and pregnancy. It does NOT change across breast sizes.

What is the role of prolactin in first initiation of lactation?

Role during breastfeeding: Prolactin release from the anterior pituitary promotes continued milk production. Its release is stimulated by breastfeeding, and is ejected in pulses directly in sync with stimulation of the areola or breast (sucking). Elevated prolactin levels in the early days of lactation also help both milk and receptor site production.

What is secretory activation?

Secretory activation is the initiation of copious milk secretion and is associated with major changes in the concentrations of many milk constituents. The withdrawal of progesterone with the birth of the placenta triggers the onset of secretory activation, as well as increased prolactin and oxytocin.

What is secretory differentiation?

Secretory differentiation is the first process of differentiation of the mammary epithelial cells into lactocytes, with the capacity to synthesize unique milk constituents such as lactose. It occurs in mid to late pregnancy.

What are the only four stages of mammary development in the human breast?

The breast is a mammary gland and is the only organ in the human body that is not fully developed at birth. It undergoes four stages of growth and development: 1. in utero (through 2 stages) 2. at puberty (mammogenesis) 3. during pregnancy (mammogenesis/ lactogenesis I) 4. during lactation (lactogenesis II).

Breast anatomy: What are the 8 main structures of the breast?

The breast is primarily composed of glandular tissue, fibrous tissue, and adipose (fatty) tissue. The relative proportion of each type of tissue changes with a woman's age, menstrual cycle, pregnancy, and nutritional status. The 8 significant structures of the adult female breast include: 1. Mammary/Glandular tissue - Clusters of alveoli lobes, glands, and milk ducts. a) Lactocytes - milk-producing cells on the mammary epithelial layer (most inner-layer of gland). b) Myoepithelial cell layer - smooth muscle cells on the outside of the gland which contract to squeeze ready milk out into the duct. Responsible for the letdown reflex! c) Lactiferous (milk) ducts - ducts that converge and form a branched system, down which milk is drawn, connecting the clusters of glandular lobules to the nipple. 2. Adipose/fat: a) Intraglandular Fat - adipose tissue amongst the glandular tissue b) Retromammary Fat - adipose tissue at the very back of the breast c) Subcutaneous Fat - adipose tissue layer directly under the surface of the breast skin 3. Fibrous tissue/ Collagen/Elastin - surrounding the glandular milk ducts and supporting their contraction/expansion 4. Coopers ligaments - supportive ligaments joining breasts to pectoral muscles 5. Axillary nodes - a group of lymph nodes in the axilla (armpit) which collect the lymph fluid drainage from the arm and lactating breast. 6. Areola - the dark area around the nipple, highlighting it for the baby 7. Nipple - with several (4-18) lactiferous duct openings 8. Montgomery glands - a combination of milk glands and sebaceous glands. Can release some milk, but mostly oil which cleans/lubricates the nipple.

What triggers the breast to make colostrum and at what gestation?

The breast will produce colostrum if the fetus is born any time from 16 weeks. Under the influence of a 10- to 20-fold increase in placental lactogen, colostrum appears near the end of the second trimester. This is why a woman who experiences pregnancy loss after 18 weeks may experience her milk "coming in" after she gives birth. However, secretory milk-releasing alveolar cells (more mature milk) do not develop until the third trimester.

What is the lactiferous sinus?

The conventionally described lactiferous sinuses do not exist. These were thought to store a drop of milk closer to the nipple for the start of a feed. We now know that ducts can reside close to the skin surface, making them easily compressible. In fact, the majority of the glandular tissue is found within 30 mm of the nipple.

How do the first 2-4 weeks of breastfeeding form the 'launchpad' for later autocrine supply?

The first 4 weeks post-birth represents an important time for women establishing their breastmilk supply. - Whilst the copious milk production we see at day 4 or 5 or later seems to indicate an establishing supply - it is still merely an endocrine response to the delivery of the placenta. - REAL establishment of appropriate breastmilk supply occurs a few weeks later when the baby has participated in the supply and demand activities that allow the woman's breasts to make enough and not too much breastmilk for their baby/babies. Thus, breastfeeding/breast drainage in the first 2-4 weeks will have a big impact on later supply... it is essential to communicate this to women. - This has implications for when babies are offered formula top-ups at this time and for women who are expressing only during this time too (because of the difficulty of judging and ensuring adequate drainage). - It is more difficult for women with milk supply problems later on to increase their supply.

Why is it vital for the baby to ingest breastmilk, not formula, as its first food after birth?

The newborn gut is sterile and highly permeable.

Oxytocin is released from where?

The posterior pituitary gland.

What is the ratio of whey:casein protein in mature breastmilk?

The whey:casein ratio of mature breastmilk is initially 80:20. This 80% whey is what can often make mature breastmilk a bluish-white colour. Ratio then moves toward 60:40 in mature milk, then 50:50 by late lactation.

How is human breastmilk unique from other mammal milks?

Unique: Breast milk is not a uniform body fluid but a mammary gland secretion of changing composition. No two samples of breast milk are the same, even when taken from the same mother. Nutritious: Human milk is a living, highly complex substance with a balance of nutrients and an array of functional properties that promote metabolic efficiency. It is a living fluid composed of more than 200 known ingredients, including vitamins, minerals, trace elements, protein, fat, and carbohydrates. It contains 4,000 live cells (mostly leukocytes) per millilitre. Protective antibodies: Breast milk offers antibody protection for the infant, who is protected through passive immunity from any diseases for which the mother has developed antibodies. This protection continues as long as the baby is breastfeeding. Specific (nutrition): Although breast milk is not uniform, variations in milk composition are functional, interactive and not random. Breast milk contains "species specific" nutrients. When an infant suckles, the release of 19 different gastrointestinal hormones occurs for both the mother and the infant. These hormones stimulate growth of intestinal villi, increasing the surface area and the absorption of calories with each feeding. Infant guided: Because breastfeeding is an interactive process, the infant helps to determine the milk's composition.

Which component of breastmilk varies most with maternal diet?

Vitamins

When does the transition of lactation from endocrine to autocrine control occur? What is the hormonal process of this transition?

When Lactogenesis II is completed and there is copious production of breastmilk, the regulation of milk supply gradually changes from endocrine-based to autocrine-based. This becomes Lactogenesis III, or galactopoiesis - meaning that, very gradually, the amount of milk produced will mirror the infant's needs, and 'settle down' into a rhythm. ENDOCRINE: * Lactogenesis I and the period up to Lactogenesis II is under endocrine control, governed by prolactin. * Essentially, as long as the proper hormones are in place, mom will start making colostrum about halfway through pregnancy (Lactogenesis I) and her milk will increase in volume (Lactogenesis II - copious milk production) around 30-40 hours after birth. AUTOCRINE: * It is helpful to consider Lactogenesis as a 2 stage process: 1. It starts with the birth of the placenta and subsequent drop in progesterone, oestrogen, placental lactogen and gradual closure of the inter-mammary cells. Prolactin is no longer inhibited, leading to copious milk production in 40+ hours post-birth. 2. THEN - the change to autocrine control of milk production (galactopoiesis/ Lactogenesis III) involves the gradual activation of the mechanisms for the Feedback Inhibitor of Lactation (FIL). * Prolactin levels gradually decrease with no impact on milk production. * Some research indicates that there is a 2-4 week period in which this process establishes. One theory is that prolactin receptors are produced in greater number during this period if there is frequent emptying of the breast.

Which cells are destroyed with milk freezing?

White cells like T- and B-lymphocytes