3/22/2011. Research Validation of How Breastfeeding Works. In Utero. Training Agenda

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1 Research Validation of How Breastfeeding Works Training Agenda Synthesis and Secretion of Breastmilk Changes in Volume and Composition of Breastmilk Breastfeeding Patterns of babies How Babies Regulate Milk Production In Utero Fetus receives continuous nutrition

2 After birth Exclusive breastfeeding is the optimum way to nourish babies from birth to 6 months old, 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 Body weight loss Cholesterol clearance Suppression of maternal fertility. Diabetics Baby Gold Standard infant food Facilitates growth and development Protects against illness How is breastmilk made? Alveoli group of lactocytes Blood supply Myoepithelial cells Lactocyte Milk Duct 2

3 How is breastmilk made? Alveoli group of lactocytes How is human milk manufactured? Lactocyte milk making cell Blood Supply Rough Endoplasmic Reticulum Nucleus Golgi Process/Dispatch Proteins Tight/Gap Junctions Hold Cells Together Milk 3

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5 New Breast Cells 5

6 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 6

7 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 ml in first 24 hour Generally, in 3 8 breastfeeds (Arthur, 1989; Saint, 1984) ml from 2 6 days Generally, in 5 10 breastfeeds (Arthur, 1989; Saint 1984; Casey, 1986; Glassier, 1990) 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) 7

8 Secretory Activation Composition Changes Increase in lipid content, casein, lactose, potassium, citrate, calcium, phosphate Decrease in total t 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) Number of Mothers Range of Milk Production (71 Western Australian Mothers) 24 h Milk Production (ml) 8

9 Infra-red Image of Lactating Breast Storage Capacity Computerized Breast Measurement 9

10 Established Lactation Storage Capacity Storage capacity is the maximum amount of milk that can bestored 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) Storage Capacity and Available Milk 2000 t Volume (ml) Breast Right breast Storage Capacity Available Milk Left breast Time of Day 6:30 16:30 20:30 12:30 10

11 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. Breast is not drained after each feed e of Fullness Degree Storage Capacity: 192 ml Average Feed: 80 ml 6:00 12:00 18:00 0:00 6:00 12:00 Time of Day Established Lactation Milk storage is a function of the mother s breast anatomy and the baby s appetite. 11

12 Established Lactation Lung Capacity Tidal volume is the amount of air taken in during normal breathing. Vital capacity is the largest amount of air that can be exhaled ed after taking a deep breath. Expiratory reserve is the air that is left in the lungs after exhaling in normal breathing. Established Lactation Lung Capacity In the average adult, the amount of air that can be exhaled from a deep breath is about 4.5 L (8.4 pints.) Awell-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.) Established Lactation Breastmilk Storage Capacity Similarly, breastfeeding storage capacity can: Increase if the breast us consistently well-drained. Decrease if the demand d on the breast decreases. 12

13 Established Lactation Appetite cream skim milk Established Lactation Appetite If fat content before a feed is <4%, breast is reasonably full with a significant amount of milk available to the baby. If fat ftcontent tafter a feed dis >10%, breast is reasonably well drained indicating baby has taken most of the available milk. 13

14 Demand and Supply 350 Basal Peak Plasma Prolactin (µg/l) Milk Production (ml/d) Month of Lactation Demand and Supply 14

15 The more the breast is drained, the faster the milk is made 2000 Breast Volume (ml) :30 16:30 2:30 12:30 Time of Day Demand and Lactation Do they both produce the same quantity of milk? Difference Between Breasts h Milk Production (ml) P < ml) (range More Productive Kent, 2006 Less Productive 15

16 Breastfeeding Patterns Feed on Demand Breastfeeding Patterns A breastfeed is defined as a feed from one breast. During a breastfeed, a baby may: feed from one breast (unpaired breastfeed) OR feed from both breasts (two paired breastfeeds) within 30 min OR have a cluster of breastfeeds Left Right Unpaired Feeds (30% of babies) Paired Feeds (13% of babies) Fee ed (ml) :00 12:00 18:00 0:00 6:00 Time of Day 24h Production Left Breast 253 g Right Breast 534 g Total 787 q 0 12:00 18:00 0:00 6:00 12:00 18:00 Time of Day 24h Production Left Breast 353 g Right Breast 397 g Total 750 q 16

17 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.) Breastfeeding Patterns Babies who are exclusively breastfed on demand show a wide range of breastfeeding behavior. (Kent, 2006) Breastfeeding Patterns Normal Breastfeeding Behavior Average Range Number of Feeds Average Feed (ml) Storage Capacity (ml) % Avail Milk Removed Fat Content (g/l) h Production (ml)

18 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. Feeding Frequency Month of Lactation Feeds Meals Night Feeds Breastfeeding Patterns The baby gets enough fat if it has many small feeds or few large feeds 18

19 % Cream Fat Intake is adequate Fore milk Hind milk Mother A Average Feed 39 g Average Storage Capacity 200 g 24-h Milk Production 673 g 6pm 9pm 12am 3am 6am 9am noon 3pm 6pm 24-h Fat Intake 30 g Mother B Average Feed 103 g Average Storage Capacity 168 g 24-h Milk Production 782 g 24-h Fat Intake 32 g 12am 3am 6am 9am noon 3pm 6pm 9pm 12pm Time of Day Fat intake range g/24h Independent of feed frequency Extended Lactation and Involution Changes in milk composition occurs with gradual weaning (introduction of complementary feeds) after 6 months Decrease Glucose, citrate, phosphate, calcium Increase Fat, lactose, protein, sodium Breast Tissue During Weaning 19

20 Acknowledgements Peter Hartmann Jackie Kent 20