3/22/2011 Research Validation of How Breastfeeding Works - - PDF document

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Research Validation

• f

How Breastfeeding Works

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Training Agenda

Synthesis and Secretion of Breastmilk Changes in Volume and Composition of Breastmilk Breastfeeding Patterns of babies How Babies Regulate Milk Production

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In Utero

Fetus receives continuous nutrition

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Exclusive breastfeeding is the optimum way to nourish babies from birth to 6 months old, and it is recommended that breastfeeding

After birth …

and it is recommended that breastfeeding continues into the second year of life and

• beyond. World Health Organization 2001

Advantages of Breastfeeding:

Mother

Recover from childbirth

Baby

Gold Standard infant food Facilitates Body weight loss Cholesterol clearance Suppression of maternal fertility. Diabetics Facilitates growth and development Protects against illness

How is breastmilk made?

Alveoli ‐ group of lactocytes

Myoepithelial cells Blood supply Milk Duct Lactocyte

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How is breastmilk made?

Alveoli ‐ group of lactocytes

Blood Supply Rough Endoplasmic Reticulum Nucleus

How is human milk manufactured?

Lactocyte – milk making cell

Golgi Process/Dispatch Proteins Tight/Gap Junctions Hold Cells Together Milk

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New Breast Cells

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Maternal Diet: Volume and Composition

NO….diet is not a factor

Maternal Diet: Volume and Composition

Energy Content = determined by concentrations of lactose, fat and protein 630 Kcal/day is energy required to produce average daily milk production. On average, breastfeeding mothers lose 2 kg more body weight over 6 months of lactation compared with mothers who do not breastfeed.

Maternal Volume and Composition

Well balanced diet is important Diet does affect concentrations of some vitamins and minerals in breast milk. AAP Guidelines for Vitamin D supplementation

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Secretory Differentiation

Lactogenesis I

Ability to secrete milk components during pregnancy

Secretory Activation

Lactogenesis II

Prolactin Insulin Adrenal Cortisol Occurs about 60 hours postpartum Oxytocin release causes MER (milk ejection reflex) Secretory Activation

Volume Changes Babies volume of feeds change from day to day

0 – 5 mL within 60 minutes of birth 7 – 123 mL in first 24 hour

Generally, in 3‐8 breastfeeds (Arthur, 1989; Saint, 1984)

395 – 868 mL from 2‐6 days

Generally, in 5‐10 breastfeeds (Arthur, 1989; Saint 1984; Casey, 1986; Glassier,

1990)

750 – 800 mL by 1 month of age (Hartmann, 1995; Kent, 2006; Cox 1996;)

Milk production on day 6 is significantly associated with milk production at week 6. (Neville, 1991)

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Secretory Activation

Composition Changes Increase in lipid content, casein, lactose, potassium, citrate, calcium, phosphate D i t t l t i di d hl id Decrease in total protein, sodium and chloride

(Thrift, 1999, Harzer, 1986; Neville, 1991; Kunz, 1992)

Changes in lactose, citrate, protein and sodium are biochemical markers that Secretory Activation has taken place. (Arthur, 1989; Cregan, 2002)

Established Lactation

Milk Volume and Composition Baby’s growth rate is related to the total amount of milk consumed rather than the concentration of fat, protein or

• lactose. (Kent, 1999; Butte, 1984)

Range of Milk Production

(71 Western Australian Mothers) Mothers

12 14 16 18 20

Number of

24‐h Milk Production (mL)

2 4 6 8 10

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Infra-red Image of Lactating Breast

28.0 30.0 32.0 20.0 22.0 24.0 26.0

Storage Capacity

Computerized Breast Measurement

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Established Lactation

Storage Capacity Storage capacity is the maximum amount of milk that can be stored in the breast and is available to the infant be stored in the breast and is available to the infant under normal patterns of breastfeeding.

Established Lactation

Storage Capacity Relates to the amount of milk available to the baby ranges from 81 to 606 mL (Daly, 1993)

t Volume (mL) Storage Capacity 2000 1800 1600 Available Right breast

Storage Capacity and Available Milk

Breast 6:30 16:30 20:30 12:30 1600 1400 1150 1050 950 Milk Time of Day Left breast

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Established Lactation

Appetite Babies do not drain the breast at each feed ~ 1or more times/day. On average, take only 67% of the available milk Indicates babies feed according to appetite; they do not stop feeding because the breast is empty.

e of Fullness

0.6 0.8 1.0

Breast is not drained after each feed

Degree

Storage Capacity: 192 mL Average Feed: 80 mL 0.0 0.2 0.4 6:00 12:00 18:00 0:00 6:00 12:00

Time of Day

Milk storage is a function of the mother’s breast anatomy and

Established Lactation

mother s breast anatomy and the baby’s appetite.

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Tidal volume is the amount of air taken in during normal breathing. Vital capacity is the largest amount of air that can be exhaled after taking a deep breath.

Established Lactation

Lung Capacity

e a ed a e a g a deep b ea Expiratory reserve is the air that is left in the lungs after exhaling in normal breathing. In the average adult, the amount of air that can be exhaled from a deep breath is about

4.5 L (8.4 pints.)

A well-trained athlete has a greater lung capacity. The

Established Lactation

Lung Capacity

A well trained athlete has a greater lung capacity. The average amount of air she could exhale from a deep breath is 6.5 L (12 pints.)

Similarly, breastfeeding storage capacity can:

Increase if the breast us consistently well-drained. D if th d d th b t d

Established Lactation

Breastmilk Storage Capacity

Decrease if the demand on the breast decreases.

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Established Lactation

Appetite

cr cream eam skim milk skim milk

If fat content before a feed is <4%, breast is reasonably full with a significant amount of milk available to the baby. If f t t t ft f d i 10% b t

Established Lactation

Appetite If fat content after a feed is >10%, breast is reasonably well‐drained indicating baby has taken most of the available milk.

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Maintaining Lactation

Demand and Supply

Milk Production 200 250 300 350 Plasma P l ti 500 600 700 800 900

Basal Peak

Production (mL/d) 50 100 150 1 2 4 6 Month of Lactation Prolactin (µg/L) 100 200 300 400

Maintaining Lactation

Demand and Supply

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The more the breast is drained, the faster the milk is made

Breast Volume (mL)

2000 1800 6:30 16:30 2:30 12:30

Time of Day

1600 1400

Maintaining Lactation

Demand and Lactation

Do Do they ey bot both pr produ

• duce t

ce the e same qu me quan antity of

• f milk?

milk?

Difference Between Breasts

24‐h Milk Production (mL)

P < 0.0001 300 400 500 9 mL) More Productive Less Productive 100 200 (range 161 ‐769

Kent, 2006

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Maintaining Lactation

Breastfeeding Patterns

“Feed on Demand”

A breastfeed is defined as … a feed from one breast. During a breastfeed, a baby may:

Maintaining Lactation

Breastfeeding Patterns

feed from one breast (unpaired breastfeed) OR feed from both breasts (two paired breastfeeds) within 30 min OR have a cluster of breastfeeds

Paired Feeds (13% of babies) Unpaired Feeds (30% of babies)

ed (mL)

60 80 100 120 140 60 80 100 120 140

Maintaining Lactation

Left Right

24h Production Left Breast 253 g Right Breast 534 g Total 787 q 24h Production Left Breast 353 g Right Breast 397 g Total 750 q

Fee Time of Day

6:00 12:00 18:00 0:00 6:00

Time of Day

20 40 60 12:00 18:00 0:00 6:00 12:00 18:00 20 40 60

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Maintaining Lactation

Breastfeeding Patterns

11 breastfeeds/day (on average) but ranged from 6 – 18 feeds.

( )

They took these breastfeeds as 8 meals (on average) but ranged from 4 – 13 meals (Kent, 2006.)

Babies who are exclusively breastfed on demand show a

Maintaining Lactation

Breastfeeding Patterns

wide range of breastfeeding behavior.

(Kent, 2006)

Maintaining Lactation

Breastfeeding Patterns

Normal Breastfeeding Behavior

Average Range

Number of Feeds 11 6-18 Number of Feeds 11 6 18 Average Feed (mL) 76 30-135 Storage Capacity (mL) 179 74-382 % Avail Milk Removed 67 43-92 Fat Content (g/L) 41 22-62 24-h Production (mL) 798 478-1298

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Maintaining Lactation

Breastfeeding Patterns Most babies feed at night, often the time of the biggest breastfeed from a full breast. Babies who do not feed at night usually had their largest breastfeed in the morning-when breasts were usually full.

Feeds Meals

6 8 10 12

Maintaining Lactation

Feeding Frequency

Meals Night Feeds

2 4 6 2 4 6

Month of Lactation

Maintaining Lactation

Breastfeeding Patterns The baby gets enough fat if it has many small feeds or few large feeds

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% Cream

Fat Intake is adequate

2 4 6 8 10 12 14

Mother A Average Feed 39 g Average Storage Capacity 200 g 24-h Milk Production 673 g 24-h Fat Intake 30 g

6pm 9pm 12am 3am 6am 9am noon 3pm 6pm

Fore‐milk Hind‐milk

Fat intake range 15–50 g/24h Independent of feed frequency 2 4 6 8 10 12 14

Time of Day

12am 3am 6am 9am noon 3pm 6pm 9pm 12pm

Mother B Average Feed 103 g Average Storage Capacity 168 g 24-h Milk Production 782 g 24-h Fat Intake 32 g

Maintaining Lactation

Extended Lactation and Involution Changes in milk composition occurs with gradual weaning (introduction of complementary feeds) after 6 months

Decrease Increase

Glucose, citrate, phosphate, calcium Fat, lactose, protein, sodium

Maintaining Lactation

Breast Tissue During Weaning

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Acknowledgements

Peter Hartmann Jackie Kent